Patent Publication Number: US-2023157734-A1

Title: Vertebral joint implants and delivery tools

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. Ser. No. 15/198,718, filed on Jun. 30, 2016, entitled “Vertebral Joint Implants and Delivery Tools, which is a continuation of Ser. No. 14/297,861, filed on Jun. 6, 2014, entitled “Vertebral Joint Implants and Delivery Tools,” now U.S. Pat. No. 9,629,665, which is a continuation application of Ser. No. 13/627,825, filed Sep. 26, 2012, entitled “Vertebral Joint Implants and Delivery Tools,” now U.S. Pat. No. 8,753,347, which is a continuation application of Ser. No. 12/653,283, filed on Dec. 10, 2009, entitled “Vertebral Joint Implants and Delivery Tools,” now U.S. Pat. No. 8,425,558, which is a continuation-in-part “CIP” application of Ser. No. 12/455,814, filed Jun. 5, 2009, entitled “Facet Joint Implants and Delivery Tools,” now U.S. Pat. No. 8,361,152, which claims priority to U.S. Provisional Patent Application No. 61/169,601, filed on Apr. 15, 2009, entitled “Facet Joint Implants and Delivery Tools”, and is a Continuation-in-part “CIP” application of Ser. No. 12/317,682, filed on Dec. 23, 2008, entitled “Facet Joint Implants and Delivery Tools,” now U.S. Pat. No. 8,267,966, which claims priority to U.S. Provisional Application No. 61/109,776 filed on Oct. 30, 2008, entitled “Facet Joint Implants” and U.S. Provisional Application No. 61/059,723, filed Jun. 6, 2008, entitled “Spine Distraction Device.” The full disclosures the above listed patent applications are hereby incorporated by reference herein. 
    
    
     FIELD OF INVENTION 
     The following detailed description relates to a device for distracting the spine. More particularly the description relates to a tool for distracting a facet joint of the spine and an implant for maintaining the distracted position of the joint. More particularly the description relates to an implant that may be used together with a tool to distract a facet joint, the implant remaining in place separated from the tool. In some instances, the implant itself may extract the joint. 
     BACKGROUND 
     Chronic back problems cause pain and disability for a large segment of the population. Adverse spinal conditions may be characteristic of age. In particular, spinal stenosis (including, but not limited to, central, canal, and lateral stenosis) and facet arthropathy may increase with age. Spinal stenosis results in a reduction of foraminal area (i.e. the available space for the passage of nerves and blood vessels), which may compress cervical nerve roots and cause radicular pain. Both neck extension and ipsilateral rotation, in contrast to neck flexion, may further reduce the foraminal area and contribute to pain, nerve root compression, and neural injury. 
     Cervical disc herniations may be a factor in spinal stenosis and may predominantly present upper extremity radicular symptoms. In this case, treatment may take the form of closed traction. A number of closed traction devices are available that alleviate pain by pulling on the head to increase foraminal height. Cervical disc herniations may also be treated with anterior and posterior surgery. Many of these surgeries are performed through an anterior approach, which requires a spinal fusion. These surgeries may be expensive and beget additional surgeries due to changing the biomechanics of the neck. There is a three percent incidence of re-operation after cervical spine surgery. Moreover, these surgeries may be highly invasive leading to long recovery times. 
     There is a need in the art for a device and procedure to increase foraminal height to reduce radicular symptoms of patients suffering the effects of spinal stenosis. There is also a need for the device to be adapted to allow for the procedure to be minimally invasive and to avoid modifying the biomechanics of the spine. 
     SUMMARY OF THE INVENTION 
     In one embodiment, a spinal joint distraction system may include a driver assembly including a tubular shaft having a longitudinal axis and a pair of implant holder arms positioned on a distal end of the tubular shaft, where the arms are configured to hold a spinal implant. In another embodiment, the driver assembly may also include an implant distractor positioned along the longitudinal axis near the distal end of the tubular shaft, an internal actuator positioned within the tubular shaft and adapted to advance the implant distractor, and a distractor knob adapted to control the internal actuator. In another embodiment, the system may also include a delivery device with a tubular shaft, a receiving assembly positioned on a proximal end of the tubular shaft, and a pair of forks extending from a distal end of the tubular shaft, where the may be adapted to penetrate a facet joint and the delivery device may be adapted to slidably receive the driver assembly. In some embodiments, the system may include an implant adapted for holding by the implant holding arms of the driver assembly. In some other embodiments, the system may include a chisel with a shaft portion, a tip at a distal end of the shaft, and a head at a proximal end of the shaft, where the delivery device is adapted to receive the chisel, and the head of the chisel is adapted to be tapped by a driving member to insert the tip of the chisel into a facet joint. In still other embodiments, the system may include an injector with a cannula with a closed distal end and two exit doors positioned on opposite sides of the distal end, a plunger with a seal positioned within the cannula, a stop disc at a proximal end of the cannula, and a handle positioned on a proximal end of the plunger, where the delivery device is further adapted to receive an injector. 
     In another embodiment, the internal actuator may be a stand alone device insertable into the driver assembly. In another embodiment, the internal actuator may include a handle and an internal rod, the internal rod being adapted to hold an implant distractor, and the handle being configured to release the implant distractor. In another embodiment, the system may include a collet positioned on a distal end of the internal rod, the collet adapted to securely hold the implant distractor. 
     In another embodiment, a spinal distraction implant may include an upper member and a lower member, the upper and lower member being generally rectangular and each having a distal edge, a proximal edge, and two parallel lateral edges, the upper and lower member positioned adjacent and substantially parallel to each other and having an inner surface and an outer surface, the distal edges of the upper and lower member connected to each other and the proximal edges adapted to receive an implant distractor, and teeth positioned along the lateral edges of at least one of the upper or lower member and extending outwardly. In another embodiment, the implant may include flanges extending substantially orthogonally from a proximal end of the upper and lower members. In some embodiments, the flanges may include openings for receiving anchors to anchor the implant to a lateral mass of a facet joint. In another embodiment, the implant may include a truncated threaded slot adapted to engage a cross-cut thread feature of an implant distractor. In another embodiment, the upper and lower members may each include an interlocking scissor feature. 
     In another embodiment, a method of distracting a facet joint of the spine may include inserting a delivery device to access the facet joint of a patient, inserting a driver assembly holding an implant into the delivery device, and actuating the driver assembly thereby distracting the implant. 
     In another embodiment, a spinal distraction implant may include an upper member, a lower member, and a proximal member, the upper and lower members being generally rectangular and each having a distal edge and two parallel lateral edges, the upper and lower members extending generally continuously into each other to form the proximal member, the upper and lower member positioned adjacent and substantially parallel to each other and having an inner surface and an outer surface, the proximal member being generally perpendicular relative to the upper and lower members, at least one of the upper and lower members further including threaded slots adapted to receive threads of an implant distractor and outwardly extending teeth positioned along the lateral edges of at least one of the upper or lower members. In another embodiment, the proximal member may include a penetration for receiving an implant distractor. 
     In another embodiment, a spinal distraction implant may include a threaded bolt with a proximal end terminating in a head, a proximal non-threaded block positioned along the bolt and abutting the head of the bolt, a distal threaded block positioned a distance away from the proximal threaded block, and a plurality of expansion members positioned between the proximal and the distal threaded blocks. In one embodiment, the plurality of expansion members may be V-shaped members. In another embodiment, the plurality of V-shaped members may be adapted to deformably flatten out and expand laterally when compressed between the distal and proximal blocks. In another embodiment, the plurality of expansion members may be planar plates with slotted holes such that when freely positioned on the bolt, the plates are positioned in a skewed position relative to a longitudinal axis of the bolt. In another embodiment, the planar plates may be adapted to engage one another and thus position themselves perpendicular to the bolt when compressed between the distal and proximal blocks. 
     In another embodiment, a spinal distraction implant may include a pair of stacked structures separated by a sloping plane, the structures having an engagement surface along the plane including ratchet teeth. In one embodiment, a first structure of the pair of stacked structures increases in thickness in a proximal direction and a second structure of the pair of stacked structures increases in thickness in a distal direction. 
     In another embodiment, a spinal distraction implant may include a generally tapered shaft in the form of a screw, the shaft defining a longitudinal axis and having a length, the shaft having threads along an outer surface for engaging articular surfaces of a facet joint. In one embodiment, the threads may be notched along the length of the implant creating serrations for cutting into the articular surfaces of a facet joint. In another embodiment, the threads may include leaf springs for preventing backing out of the implant. In another embodiment, the threads may have a T-shaped cross-section. In another embodiment, the implant may include a relatively broad head with a decorticating feature on a distal surface thereof. In another embodiment, the decorticating feature may include tabs projecting distally from the head. In another embodiment, the decorticating feature may include spurs. In another embodiment, the head may be in the form of a floating collar and be free to pivot about the longitudinal axis of the implant in a ball and socket type fashion. In another embodiment, the implant may include a torque limiting mechanism. In another embodiment, the shaft may include a hollow cavity and take the form of a cone, the cone being made from a relatively malleable material, the implant further including an inner core support member for use when inserting the implant and for removal once the implant is in place. In still another embodiment, the generally tapered shaft may be a first tapered shaft and the implant may also include a second generally tapered shaft in the form of a screw where the second generally tapered shaft may be positioned adjacent to the first generally tapered shaft and have communicative threaded serrations such that when one shaft is rotated, the other shaft rotates in the opposite direction. In another embodiment, the implant may include an arm type locking mechanism, the arm being biased in a distal direction such that when implanted the arm provides a biasing force to maintain friction on the threads. In another embodiment, the arm may have engaging teeth. In another embodiment, the implant may include flaps extending from the head of the shaft and including teeth for engaging a lateral mass of a facet joint. 
     In another embodiment, a spinal distraction implant may include a plate and a orthogonally positioned bumper, the superior aspect of the bumper having a rounded surface for opposing the lateral mass of a superior vertebra, the implant including an anchoring screw for securing the implant to a lateral mass of a facet joint. 
     In another embodiment, a spinal distraction implant may include a wedge insertable between facet surfaces, the wedge having teeth on at least one of an anterior and inferior surface thereof. In another embodiment, the implant may also include a diagonally placed anchor screw positioned through the implant for advancing into the surface of a facet joint. 
     In another embodiment, a spinal distraction implant may include an anterior hook, a posterior hook, and a bolt joining the anterior and posterior hook. In another embodiment, the anterior hook may be C-shaped with a lip and the posterior hook may be S-shaped with a lip, the anterior hook adapted to engage the anterior aspect of the inferior facet and the posterior hook adapted to engage the posterior aspect of the posterior facet. 
     In another embodiment, a spinal distraction implant may include an insert and tabs positioned to extend orthogonally from a proximal end of the insert. In one embodiment, the insert may be rectangular and the tabs may have holes for receiving an anchor. 
     In another embodiment, a spinal distraction implant may include a collapsible diamond shaped structure including two opposing threaded corners, and two opposing non-threaded corners including pads. The implant may also include a bolt threaded through the threaded corners of the diamond shaped structure, where actuating the bolt draws the threaded corners together and extends the non-threaded corners. 
     In another embodiment, a spinal distraction implant may include an upper member, a lower member, a hinge connecting the upper member to the lower member, and a brace member for maintaining the implant in an open position. 
     In another embodiment, a spinal distraction implant may include a generally cylindrically shaped member including at least two sections separated by a slot, the sections connected together at distal ends to form a tip, the member adapted to receive a screw to cause it to expand, and the outer surface of the sections including teeth for engaging articular surfaces of a facet joint. 
     In another embodiment, a method of securing a superior verterbra may include applying a force to the superior vertebra to increase the foraminal area between the superior vertebra and an inferior vertebra and placing an angled screw through a superior facet, through a facet capsule, and into an inferior facet. 
     In another embodiment, a spinal distraction implant may include a collapsible triangular shaped implant including a central shaft and at least two springing leaves connected to the distal end of the shaft, extending proximally along the shaft, and biased in a direction to form an arrow shape, where the implant may be collapsed within a tube and delivered to a site where the tube is removed and the implant is allowed to expand. 
     In another embodiment, a spinal distraction implant may include a facet spacer plate and screw, wherein the screw may be inserted diagonally through a facet surface to engage the facet spacer plate thereby forcing separation of a facet joint. In another embodiment, the spacer may have a C-shape and the screw may pass through the spacer plate prior to entering the spinal structure. 
     In another embodiment, a spinal distraction implant may include a first bracket, second bracket, and a bolt extending between the brackets, where the brackets are adapted to separate when the bolt is turned. In another embodiment, the first and second brackets may be adapted to be attached to a lateral mass of a facet joint. In yet another embodiment, the first and second brackets may include a leg adapted to be inserted into a facet joint. 
     In another embodiment, a spinal distraction implant may include a triangular shaped wedge, an anchor screw positioned diagonally through the wedge, and a malleable flap extending from the wedge including teeth for engaging a lateral mass of a facet joint. 
     In another embodiment, a spinal distraction implant may include an anchoring plug, an expandable plate, and two external plates, where securing the external plates to a lateral mass of a facet joint and inserting the anchoring plug causes the facet joint to separate. 
     In another embodiment, a spinal distraction implant may include a delivery system and at least two nitinol hooks, where the hooks may be flattened and inserted with the delivery system and once in place may be allowed to assume their pre-flattened shape. 
     In another embodiment, a spinal distraction implant may include a hollow screw sleeve having barbs adapted to be ejected from a retracted position and a wedge adapted to be inserted in the hollow screw sleeve to eject the barbs. 
     In another embodiment, a spinal distraction implant may include a collapsible nut positioned over a bolt, the bolt defining a longitudinal axis, where advancing the bolt may cause the nut to collapse along the longitudinal axis in an accordion shape, thereby expanding laterally. 
     In another embodiment, a spinal distraction implant may include a collapsible plate positioned over a bolt, the bolt defining a longitudinal axis, where advancing the bolt causes the plate to collapse along the longitudinal axis in an accordion shape, thereby expanding laterally. 
     Another embodiment, a spinal distraction implant may include a wire surrounding a block in a helical fashion, the wire adapted to contract and expand laterally when pulled taught or released respectively. 
     In another embodiment, a spinal distraction implant may include an outer housing and an internal spring, where the housing may be biased to be in a laterally broad position when the spring is in a neutral position. 
     In another embodiment, a spinal distraction implant may include a pair of stacked structures separated by a sloping plane and a fastener positioned at an angle through the pair of structures thereby preventing relative movement along the plane. 
     In another embodiment, a spinal distraction implant may include a collapsible cylinder with side cutouts, the cylinder made from a resilient elastic material. 
     In another embodiment, a spinal distraction implant may include a distal tip of a delivery tool, where the tip is adapted to distract a facet joint and detach from the delivery tool. 
     In another embodiment, a spinal distraction implant may include a housing, a central gear rotatably positioned within the housing, and two plates slidably positioned in the housing and positioned opposite one another adjacent to the central gear and including teeth for engaging the gear, where rotating the gear slidably extends the plates beyond an outer surface of the housing in opposite directions. 
     In another embodiment, a spinal distraction implant may include a triangularly bent plate with a first and second bracket on each side, the first bracket adapted to receive an anchor screw and the second bracket including teeth for biting into a lateral mass of a facet joint. 
     In another embodiment, a spinal distraction implant may include a rotatable cone with a longitudinal axis including a shoulder with a ledge defining a cam surface and an anchor screw, where the shoulder is adapted to be inserted into a facet joint and the implant rotated to cause a superior facet to ride upward along the cam surface and distract the joint, wherein the screw may be advanced to secure the implant. 
     In another embodiment, a spinal distraction implant may include a housing with penetrations for ejection of spikes, internal spikes positioned with the housing and in alignment with the penetrations, and an internal wire routed through the spike positions, where pulling the wire taught forces the spikes from the housing to engage articular surfaces of a facet joint. 
     In another embodiment, a spinal distraction implant may include a housing, a cavity within the housing, penetrations on lateral surfaces of the housing extending from the cavity through the wall of the housing, spikes positioned to be ejected through the penetrations, the spikes having a beveled inner surface, and a piston having a torpedo shaped distal end positioned within the cavity, where advancing the piston engages the torpedo shaped distal end with the beveled inner surface of the spikes causing them to eject through the penetrations and engage articular surfaces of a facet joint. 
     In another embodiment, a spinal distraction implant may include two parallel equal length side bars and at least two struts pivotably positioned between the side bars at each end, the struts having textured surfaces on each end thereof, where the struts may be pivoted to lie in plane with and parallel to the side bars and once in position in a facet joint, may be pivoted substantially perpendicular to the side bars to distract the facet joint. 
     In another embodiment, a spinal joint distraction system may include a delivery device with a tubular shaft, a receiving assembly positioned on a proximal end of the tubular shaft and including a seating cavity, and a pair of forks extending from a distal end of the tubular shaft, the forks adapted to penetrate a facet joint. The system may also include a chisel including a shaft with a chamfered tip, the chisel being adapted for slidable insertion through the delivery device. The system may further include a decorticator sleevably positioned on the tubular shaft of the delivery device, the decorticator including a tubular shaft portion with a chamfered distal end, a plurality of serrated teeth at the distal tip of the chamfered end, a beveled edge extending along the periphery of the chamfered distal end, and a handle positioned on the proximal end of the tubular shaft portion, the handle having a bore adapted to receive a gripping tool and a threaded bore for receiving a set screw. The system may also include a driver assembly adapted for slidable insertion through the delivery device, the driver assembly including an implant shaft, a handle positioned on the proximal end of the implant shaft, and implant holding arms extending from the distal end of the implant shaft. The system may also include an internal actuator adapted for slidable insertion through the driver assembly and further adapted to advance an implant distractor, the internal actuator including a longitudinal shaft, a handle positioned on the proximal end of the longitudinal shaft and adapted to rotatably advance the implant distractor, and an internal rod including an engagement feature adapted to secure the implant distractor. The system may further include an injector adapted for slidable insertion through the delivery device, the injector including a longitudinal delivery shaft, a seating feature positioned around the shaft, and a plunger adapted to pass through the longitudinal delivery shaft causing ejection of material from the distal end of the longitudinal delivery shaft. 
     In another embodiment, a spinal joint distraction system may include a delivery device with a decorticator sleevably positioned thereon, a chisel adapted for insertion through the delivery device, a driver assembly adapted for insertion through the delivery device and further adapted to hold an implant, an internal actuator adapted for insertion through the driver assembly and adapted to deliver and advance an implant distractor thereby distracting the implant, and an injector adapted for insertion through the delivery device and further adapted to deliver flowable material to or around the joint. 
     In another embodiment, a spinal distraction implant may include an upper member and a lower member each with a distal end, the distal end of the lower member coupled to the distal end of the upper member, and an implant distractor adapted to be advanced between the upper and lower member and separate the upper and lower members causing the upper and lower member to pivot relative to one another about their respective distal ends. 
     In another embodiment, a spinal distraction implant may include an upper member and a lower member each including a distal edge, a proximal edge, and two parallel lateral edges, the edges defining a generally rectangular shape, an inner surface, an outer surface, a threaded slot passing through the member from the inner surface to the outer surface, a truncated threaded slot passing through the member from the inner surface to the outer surface, a plurality of teeth spaced along the two parallel lateral edges, a guide feature positioned on the proximal edge, and an interlocking scissor feature positioned on the distal edge. The implant may also include an implant distractor including a cylindrical body tapering to a point at a distal end, a coil shaped thread feature having an abrupt proximal end and being interrupted by at least one cross-cut, and an annular stop ring; wherein the upper and lower members may be pivotally coupled to one another via their respective interlocking scissor features, the respective guide features on the upper member and the lower member may oppose one another and may be adapted to receive and guide the distal end of the implant distractor between the upper and lower members, the respective threaded slots on the upper and lower member may be adapted to receive the coil shaped thread feature, and the respective truncated threaded slots may be adapted to engage the abrupt proximal end or the at least one cross-cut of the coil-shaped thread feature. 
     In another embodiment, a method of distracting a facet joint of the spine may include dilating a path to a facet joint using a dilator set, inserting a chisel into the facet joint, advancing a delivery device over the chisel and inserting forks of the delivery device into the facet joint, removing the chisel from the joint, inserting a driver assembly with an implant into the delivery device, seating the driver assembly in the delivery device thereby positioning the implant between the forks of the delivery device and in the facet joint, inserting an internal actuator into the driver assembly and advancing an implant distractor into the implant thereby distracting the implant, actuating a button on the internal actuator thereby releasing a grip on the implant distractor and removing the internal actuator and the driver assembly, and inserting an injector and injecting a flowable material into or around the facet joint. 
     In another embodiment, a method of distracting a facet joint of the spine may include inserting a chisel into a facet joint to provide initial distraction and decorticate the surface of the joint, inserting a delivery device over the chisel to maintain the initial distraction, inserting an implant through the delivery device and into the joint, the implant having teeth adapted to engage the surfaces of the joint, distracting the implant by advancing an implant distractor, the implant distractor having a coil-shaped thread feature for engaging threaded slots of the implant, the implant distractor further having cross-cut threads for engaging truncated threaded slots on the implant, wherein, advancing the implant distractor includes causing the cross-cut threads to engage the truncated threaded slots and prevent backing out of the implant, and releasing the implant distractor and removing the delivery device thereby leaving the implant and the implant distractor in place in the joint. 
     In another embodiment, a spinal joint distraction system may include a delivery device, a driver assembly adapted for insertion through the delivery device and further adapted to hold an implant, and an internal actuator adapted for insertion through the driver assembly and adapted to deliver and advance an implant distractor thereby distracting the implant. 
     In another embodiment, a spinal joint distraction system may include a driver assembly adapted to hold an implant and an internal actuator adapted for insertion through the driver assembly and adapted to deliver and advance an implant distractor thereby distracting the implant. 
     In another embodiment, a spinal joint distraction system may include an implant, an implant distractor adapted to engage the implant, and an internal actuator adapted to advance the implant distractor thereby distracting the implant. 
     In another embodiment, a method of distracting a facet joint of the spine may include inserting a delivery device into a facet joint, inserting an implant through the delivery device and into the joint, and distracting the implant by advancing an implant distractor. 
     In another embodiment, a method of distracting a facet joint of the spine may include partially engaging an implant distractor with an implant and engaging the implant distractor with an internal actuator to form an assembly, inserting the implant portion of the assembly into the facet joint, and distracting the facet joint. 
     In another embodiment, a spinal distraction implant may include an upper member and a lower member each with a distal end, the distal end of the lower member coupled to the distal end of the upper member, wherein the upper member and lower member each comprise a plurality of threaded slots adapted to engage an implant distractor. 
     In another embodiment, a spinal distraction implant may include an upper member and a lower member each with a distal end, the distal end of the lower member including an interlocking scissor feature coupled to a corresponding interlocking scissor feature included on the distal end of the upper member. 
     In another embodiment, a spinal distraction implant comprising an upper member and a lower member, each with a distal end, the distal end of the lower member coupled to the distal end of the upper member, wherein the implant is adapted to receive an implant distractor between the upper and lower member. 
     In another embodiment, a spinal distraction implant may include an upper member and a lower member, the upper member and lower member coupled at respective distal ends, the upper and lower members being biased toward a position parallel to one another. 
     In another embodiment, a spinal joint distraction system for treating a facet joint including articular surfaces having a contour can include a delivery device including a generally tubular structure adapted to engage a facet joint, an implant adapted to be delivered through the delivery device and into the facet joint, the implant comprising two members arranged in opposed position, and an implant distractor comprising a generally elongate member adapted to advance between the two members of the implant causing separation of the members and distraction of the facet joint, wherein the implant is adapted to conform to the shape of the implant distractor upon being delivered to the facet joint. 
     The system can also include a driver assembly adapted to hold the implant and advance the implant distractor and the driver assembly can further be adapted for insertion through the delivery device. The system can also include a chisel adapted for insertion through the delivery device to facilitate initial engagement with the facet joint and a decorticator can be provided for lateral engagement with the delivery device. A malleting tool can be included with a first end adapted to engage the decorticator for a malleting process and a second end adapted to facilitate separation of parts of the system and an injector can be provided and adapted for insertion through the delivery device and further can be adapted to deliver a bone paste. 
     In another embodiment, a spinal joint distraction system can include a delivery device and chisel assembly adapted to engage a facet joint and a driver assembly adapted to hold and distract an implant, where the driver assembly can be adapted for insertion through the delivery device to deliver and distract the implant. The system can also include a place holding chisel adapted to replace the chisel and maintain the established position of the delivery device and chisel assembly. The delivery device can include a tubular shaft and a receiving assembly positioned on a proximal end of the tubular shaft and the chisel of the assembly can include a handle having a connection feature adapted to engage the receiving assembly. The connection feature can include a protrusion or recess adapted to form a detent relationship with an opposing protrusion or recess respectively. In another embodiment, the connection feature can include a latch type feature positioned on a deflectable portion of the handle, wherein advancing the chisel handle toward the receiving assembly causes the latch type feature to snap into place and depressing the deflectable portion of the handle releases the latch type feature. The receiving assembly can include a malleting anvil positioned on a proximal face of the receiving assembly and the chisel can include a slot cavity adapted to receive the malleting anvil and a malleting head adapted to engage the malleting anvil to resist relative motion between the delivery device and the chisel during malleting. The delivery device of the assembly can include forks adapted to penetrate the facet joint and it can also include a bull nose positioned on the surface of the forks near the intersection of the forks with the tubular structure, where the bull nose can be adapted to mark the position of the delivery device. The system can also include an indication hole positioned along the lateral side of the delivery device near the intersection of the forks and the tubular structure. The driver assembly can include an implant shaft having a diameter substantially equal to or less than a width of the implant and can also include a handle with a malleting bar adapted to transfer malleting blows to the driver assembly. The driver assembly can also include a slot cavity having a bearing surface where the slot cavity can be adapted to receive the malleting anvil of the receiving assembly and the bearing surface can be adapted to engage the malleting anvil to resist relative motion between the delivery device and the driver assembly during malleting. A decorticator can also be provided and can be adapted for positioning upon the delivery device from a lateral side of the delivery device. The decorticator can include a U-shaped longitudinally extending member with teeth on a distal end and it can include a malleting element at a proximal end adapted to distribute malleting blows to the longitudinally extending member. The driver assembly can include arms adapted to hold an implant and the arms can be positioned within a boundary defined by a width of the implant. 
     In another embodiment, a spinal distraction implant for the distraction of a facet joint having articular surfaces can include a first and a second member arranged in opposing position. Each of the first and second member can include a threaded slot passing through the member adapted to receive a thread feature and a plurality of teeth spaced along two parallel lateral edges, the teeth adapted to engage the articular surfaces of the facet joint, where the implant is constructed from a malleable material and is further adapted to conform to the shape of the articular surfaces upon being distracted within a facet joint. The plurality of teeth can have a linearly sloped distal face and a proximal face positioned orthogonally to the respective first or second member and the teeth can be equally spaced. The first and second members can each have an interlocking engagement feature on respective distal edges, wherein the first and second members engage one another via their respective interlocking engagement features. The first and second members can also be coupled together via a weld. 
     In another embodiment, a method of distracting a facet joint and a contralateral facet joint of a spine can include inserting a delivery device and chisel assembly into the facet joint, removing the chisel from the assembly and replacing the chisel with a place holding chisel, removing the delivery device from the facet joint, inserting the delivery device and chisel assembly into the contralateral facet joint, removing the chisel from the assembly, placing and distracting a first implant in the contralateral facet joint, removing the delivery device from the contralateral facet joint, placing the delivery device back in the facet joint via the place holding chisel, placing and distracting a second implant in the facet joint. The place holding chisel can be a radiolucent chisel and the method can also include performing lateral fluoroscopy to determine proper placement of the first implant. 
     In another embodiment, a method of distracting a facet joint of the spine can include inserting a delivery device and chisel assembly into the facet joint to provide initial distraction and decorticate the surface of the joint, removing the chisel assembly from the delivery device, inserting a driver assembly through the delivery device, the driver assembly holding an implant and further comprising an implant distractor adapted to distract the implant, distracting the implant, and removing the driver assembly and the delivery device. The method can also include positioning the delivery device and chisel assembly by selectively malleting a proximal end thereof and/or selectively malleting a proximal end of the driver assembly. A decorticator can be positioned on the delivery device from the lateral side of the device and the method can include advancing the decorticator along the length of the driver assembly, positioning a malleting tool against the proximal end of the decorticator, and malleting the malleting tool to forcibly advance the decorticator and decorticate the lateral mass of the facet joint. The decorticator can be retracted, rotated, and re-advanced to a new position for malleted with the malleting tool to decorticate a different location. Intra-operative patient symptom feedback can also be obtained. 
     In another embodiment, a spinal distraction implant delivery tool can include an implant and an assembly, where the assembly includes a means for holding the implant, a means for positioning the implant within a facet joint, and a means for distracting the implant. The implant can include a first substantially planar member and a second substantially planar member arranged in parallel and opposing position to the first substantially planar member and a biasing connection connecting the first and second planar members to one another, the biasing connection adapted to create a biasing force directed toward biasing the members toward the parallel and opposing position. The means for holding can include a pair of implant holding arms, the arms adapted to pass between the planar members and force them apart against the biasing force. The holding arms can each include a means for engaging the implant. The means for distracting the implant can include an implant distractor and a means for rotatably advancing the implant distractor. The implant distractor can include a generally elongate member adapted to pass between the substantially planar members and force the members apart against the biasing force. 
     In another embodiment, a method of performing an interbody fusion can include inserting a delivery device and chisel assembly into a joint between vertebral bodies of the spine, removing the chisel assembly from the delivery device, and inserting a driver assembly through the delivery device. The driver assembly can hold an implant and an implant distractor adapted to distract the implant. The method can also include distracting the implant and removing the driver assembly and the delivery device. In some embodiments, the method can further include repeating the steps to place a second implant in the joint. 
     Further aspects of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations thereon. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of a delivery device and chisel positioned relative to a facet joint of a spine, according to certain embodiments. 
         FIG.  1 A  is a perspective view of a chisel according to certain embodiments. 
         FIG.  2    is a perspective view of a distal end of a delivery device, according to certain embodiments. 
         FIG.  3    is a perspective view of a distal end of a delivery device with an advanced chisel, according to certain embodiments. 
         FIG.  4    is a perspective view of a distal end of a delivery device with an advanced internal decorticator, according to certain embodiments. 
         FIG.  5    is a perspective view of a delivery device and chisel positioned relative to a facet joint of a spine with a driving member positioned proximally to the chisel head, according to certain embodiments. 
         FIG.  6    is a perspective view of a delivery device with an exterior decorticator in an advanced position, according to certain embodiments. 
         FIG.  6 A- 6 C  are perspective views of a delivery device and an internal decorticator, according to certain embodiments. 
         FIG.  7    is a perspective view of a delivery device with an exterior decorticator being retracted, according to certain embodiments. 
         FIG.  8    is a perspective view of a delivery device with a driver assembly and implant poised for insertion into the delivery device, according to certain embodiments. 
         FIG.  9    is a close-up view of a distal end of a driver assembly and a delivery device, according to certain embodiments. 
         FIG.  10    is close-up view of a distal end of a driver assembly, according to certain embodiments. 
         FIG.  11    is a perspective view of an implant and a distal end of a driver assembly, according to certain embodiments. 
         FIG.  12    is a perspective view of distal end of a driver assembly holding an implant, according to certain embodiments. 
         FIG.  13    is a perspective view of a distal end of a driver assembly positioned within a delivery device, according to certain embodiments. 
         FIG.  14    is a perspective view of an implant distractor, according to certain embodiments. 
         FIG.  15    is a perspective view of a distal end of a driver assembly positioned within a delivery device, according to certain embodiments. 
         FIG.  16    is a perspective view of an implant according to certain embodiments. 
         FIG.  16 A  is a perspective view of an implant showing a guide feature, according to certain embodiments. 
         FIG.  16 B  is a perspective view of an implant showing a guide feature, according to certain embodiments. 
         FIG.  17    is a side view of an implant according to certain embodiments. 
         FIG.  18    is a top view of an implant according to certain embodiments. 
         FIG.  18 A  is a top view of an implant showing the guide feature of  FIG.  16 A , according to certain embodiments. 
         FIG.  18 B  is a top view of an implant showing the guide feature of  FIG.  16 B , according to certain embodiments. 
         FIG.  19    is a proximal end view of an implant according to certain embodiments. 
         FIG.  20    is a side view of an implant according to certain embodiments. 
         FIG.  21    is side view of a U-member according to certain embodiments. 
         FIG.  22    is a perspective view of a U-member according to certain embodiments. 
         FIG.  23    is a perspective view of an implant according to certain embodiments. 
         FIG.  23 A  is a perspective view of an implant according to certain embodiments. 
         FIG.  24    is a top view of an implant according to certain embodiments. 
         FIG.  24 A  is a side view of the implant shown in  FIG.  23 A , according to certain embodiments. 
         FIG.  25    is perspective view of a deliver device with a driver assembly inserted and advance, according to certain embodiments. 
         FIG.  26    is perspective view showing the removal of the driver assembly from the delivery device having left the implant behind, according to certain embodiments. 
         FIG.  27    is a perspective view of an injector, according to certain embodiments. 
         FIG.  28    is a perspective view of a delivery device with an advanced injector inserted and ejecting a material, according to certain embodiments. 
         FIG.  29    is a perspective view of an implant in a collapsed position according to certain embodiments. 
         FIG.  30    is a perspective view of an expanded implant according to certain embodiments. 
         FIG.  31    is a perspective view of an implant in a collapsed position according to certain embodiments. 
         FIG.  32    is a perspective view of an expanded implant according to certain embodiments. 
         FIG.  33    is a perspective view of an implant in a collapsed position according to certain embodiments. 
         FIG.  34    is a perspective view of an expanded implant according to certain embodiments. 
         FIG.  35    is a perspective view of an implant in a collapsed position according to certain embodiments. 
         FIG.  36    is a perspective view of an expanded implant according to certain embodiments. 
         FIGS.  37 A-D  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  38 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  39 A-D  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  40 A-C  include side views of an implant, according to certain embodiments. 
         FIGS.  41 A-D  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  42 A-F  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  43 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  44 A-D  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  45 A-D  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  46 A-D  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  47 A-B  include side views of an implant, according to certain embodiments. 
         FIGS.  48 A-C  include side and end views of an implant, according to certain embodiments. 
         FIGS.  49 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  50 A-B  include side views of an implant, according to certain embodiments. 
         FIGS.  51 A-B  include side views of an implant, according to certain embodiments. 
         FIGS.  52 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  53 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  54 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  55 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  56 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  57 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  58 A-B  include side views of an implant, according to certain embodiments. 
         FIGS.  59 A-B  include side views of an implant, according to certain embodiments. 
         FIGS.  60 A-B  include side views of an implant, according to certain embodiments. 
         FIGS.  61 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  62 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  63 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  64 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  65 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  66 A-C  include side views of an implant, according to certain embodiments. 
         FIGS.  67 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  68 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  69 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  70 A-C  include side views of an implant, according to certain embodiments. 
         FIGS.  71 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  72 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  73 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  74 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  75 A-B  include side views of an implant, according to certain embodiments. 
         FIGS.  76 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  77 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  78 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  79 A-C  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  80 A-D  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  81 A-C  include side views of an implant, according to certain embodiments. 
         FIGS.  82 A-F  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  83 A-B  include side and perspective views of an implant, according to certain embodiments. 
         FIGS.  84 A-B  include perspective views of an implant, according to certain embodiments. 
         FIG.  85    is an exploded perspective view of a kit, according to certain embodiments. 
         FIG.  86    is an assembled perspective view of a kit, according to certain embodiments. 
         FIGS.  87  and  88    are perspective views of a chisel portion of the kit shown in  FIGS.  85  and  86   . 
         FIGS.  89  and  90    are perspective views of a delivery device portion of the kit shown in  FIGS.  85  and  86   . 
         FIG.  91    is a perspective view of part of a driver assembly portion of the kit shown in  FIGS.  85  and  86   . 
         FIGS.  92  and  93    are perspective views of a part of a driver assembly portion of the kit shown in  FIGS.  85  and  86   . 
         FIGS.  94  and  94 A  are views of a chisel according to certain embodiments. 
         FIGS.  95 ,  95 A and  95 B  are views of a delivery device according to certain embodiments. 
         FIG.  96    is a perspective view of a driver assembly according to certain embodiments. 
         FIG.  97    is a perspective view of an internal actuator according to certain embodiments. 
         FIG.  98    is a perspective view of an injector according to certain embodiments. 
         FIGS.  99 - 99 D  are several views of a driver assembly according to certain embodiments. 
         FIGS.  100 - 101    depict relative positions of a driver assembly and a delivery device according to certain embodiments. 
         FIGS.  102 - 103    depict relative positions of an internal actuator, a driver assembly, and a delivery device according to certain embodiments. 
         FIG.  104    is a side view of an internal actuator according to certain embodiments. 
         FIG.  105    is a side view of an internal actuator according to certain embodiments. 
         FIGS.  106 - 108    are several side and cross-section view of an internal actuator according to certain embodiments. 
         FIG.  109    is a side view of a collet according to certain embodiments. 
         FIG.  110    is a side view of a longitudinal shaft of an internal actuator according to certain embodiments. 
         FIGS.  111 - 113    include several views of an implant distractor according to certain embodiments. 
         FIG.  114    is a perspective view of an injector according to certain embodiments. 
         FIGS.  115 - 116    depict relative positions of an injector and a delivery device according to certain embodiments. 
         FIGS.  117 - 120    include several perspective views of an implant according to certain embodiments. 
         FIG.  121    includes several parts of a tool according to certain embodiments. 
         FIG.  122    is a perspective view of a chisel according to certain embodiments. 
         FIG.  123    is a perspective view of a delivery device according to certain embodiments. 
         FIG.  123 A  is a perspective view of the proximal end of a delivery device according to certain embodiments. 
         FIG.  124    is a perspective view of a decorticator according to certain embodiments. 
         FIG.  125    is a perspective view of a driver assembly according to certain embodiments. 
         FIG.  126    is a perspective view of an internal actuator according to certain embodiments. 
         FIGS.  126 A and  126 B  are cross-sectional views of an internal actuator according to certain embodiments. 
         FIGS.  127  and  127 A  are perspective views of an internal rod with a collet according to certain embodiments. 
         FIG.  128    is a perspective view of an injector according to certain embodiments. 
         FIGS.  129 - 131    are several view of a dilator set according to certain embodiments. 
         FIGS.  132  and  132 A  are two views of a dilator rod according to certain embodiments. 
         FIGS.  133 ,  133 A, and  133 B  are several views of a dilator sleeve according to certain embodiments. 
         FIGS.  134  and  134 A  are two views of a dilator sleeve according to certain embodiments. 
         FIGS.  135 ,  135 A, and  135 B  are several views of a dilator sleeve according to certain embodiments. 
         FIG.  136    includes a perspective view of several parts of a tool according to certain embodiments. 
         FIG.  137    includes a perspective view of several parts of the tool of  FIG.  136   . 
         FIG.  138    is a perspective view of a chisel of the tool of  FIG.  136   . 
         FIGS.  139 A-C  include several views of a chisel of the tool of  FIG.  136   . 
         FIG.  140    is a perspective view of a malleting head of the chisel of  FIG.  138   . 
         FIG.  141    is a top view thereof. 
         FIG.  142    is a top view of a shaft portion of the chisel of  FIG.  138   . 
         FIG.  143    is a close up side view of a tip of the chisel of  FIG.  138   . 
         FIG.  144    is a top view of a chisel and delivery device of the tool of  FIG.  136   . 
         FIG.  145    is a close up side view of a tip of a chisel and delivery device of the tool of  FIG.  136   . 
         FIG.  146    is a perspective view of a decorticator of the tool of  FIG.  136   . 
         FIG.  147    is a perspective view of a driver assembly of the tool of  FIG.  136   . 
         FIG.  148    is a perspective view thereof. 
         FIG.  149    is a perspective view of several tips of several of the elements of the tool of  FIG.  136   . 
         FIG.  150    is a perspective view of the proximal ends of several of the elements of the tool of  FIG.  136   . 
         FIG.  151    is a perspective view of a plunger of the injector of the tool of  FIG.  136   . 
         FIG.  152    is a perspective view of an implant distractor, according to certain embodiments. 
         FIG.  153 A-C  are several side views thereof. 
         FIG.  154    is a perspective view of several handles and their engaging features for engaging with the receiving assembly of the delivery device of the tool of  FIG.  136   . 
         FIG.  155 A-B  include a cross-sectional view and close-up view thereof 
         FIG.  156    is a perspective view of an implant according to certain embodiments. 
         FIG.  157 - 161 B  include several perspective views thereof including the relationship of the implant to a facet joint. 
         FIG.  162    is a side view of a mechanically tested implant, according to certain embodiments. 
         FIG.  163    is a table of exemplary dimensions of an implant. 
         FIG.  164    is a table of exemplary dimensions of a delivery device. 
         FIG.  165    is a table of exemplary dimensions of an implant distractor. 
         FIG.  166    is a table of exemplary dimensions of a chisel. 
         FIG.  167    is a table of exemplary dimensions of a place holding chisel. 
         FIG.  168    is a table of exemplary dimensions of a driver assembly. 
         FIG.  169    is a table of exemplary dimensions of a decorticator. 
         FIG.  170    is a table of exemplary dimensions of a malleting tool. 
         FIG.  171    is a perspective view of a chisel according to certain embodiments. 
         FIG.  172    is a top perspective view of a distal portion thereof. 
         FIG.  173    is a bottom perspective view of a distal portion thereof. 
         FIG.  174    is a perspective view of a proximal portion thereof. 
         FIG.  175    is a top view of implants positioned in a joint between two vertebral bodies. 
         FIG.  176    is another top view of implants positioned in a joint between two vertebral bodies. 
         FIG.  177    is yet another top view of implants positioned in a joint between two vertebral bodies. 
         FIGS.  178 - 185    depict several methods according to certain embodiments. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following description generally relates to devices and methods for treating spinal stenosis. Spinal stenosis reflects a narrowing of one or more areas of the spine often in the upper or lower back. This narrowing can put pressure on the spinal cord or on the nerves that branch out from the compressed areas. Individual vertebrae of the spine are positioned relative to each other and their separation is maintained by discs separating main vertebral bodies and by capsules positioned within facet joints. The discs and capsules are separated from the bone of their respective joints by cartilage. Spinal stenosis is often indicative of degeneration of a disc, a capsule, or the cartilage in a joint, which leads to a compression of the joints and the narrowing mentioned. 
     As such, the following detailed description includes discussion of a device for distracting a facet joint of the spine to remedy this condition. The device may include a tool and an implant for distracting and maintaining the distracted position of the joint. Several embodiments of an implant are described in addition to several embodiments of a tool. In addition, several embodiments are described where the implant and the tool work together to distract the facet joint and thereafter leave the implant behind to maintain the distraction of the joint. In short, the device may be adapted to access a facet joint by inserting a delivery tool and an implant, forcibly separate the associated articular surfaces with the tool, the implant, or both, and leave the implant in place to maintain the separation of the articular surfaces. This approach may allow for maintaining the distraction of the joint, thereby relieving symptoms associated with spinal stenosis. 
     The present application hereby incorporates the following U.S. patent applications by reference herein in their entireties: U.S. patent application Ser. No. 11/618,619, which was filed on Dec. 29, 2006 and is entitled Cervical Distraction Device; U.S. Provisional Patent Application No. 61/020,082, which was filed on Jan. 9, 2008 and is entitled Methods and Apparatus for Accessing and Treating the Facet Joint; U.S. Provisional Application No. 61/059,723, which was filed on Jun. 6, 2008 and is entitled Spine Distraction Device; U.S. Provisional Application No. 61/097,103, which was filed on Sep. 15, 2008 and is entitled Cervical Distraction/Implant Delivery Device; U.S. Provisional Application No. 61/109,776, which was filed on Oct. 30, 2008 and is entitled Facet Joint Implants; U.S. Non-provisional application Ser. No. 12/317,682, which was filed on Dec. 23, 2008 and is entitled Facet Joint Implants and Delivery Tools; U.S. Non-provisional application Ser. No. 12/350,609, which was filed on Jan. 8, 2009 and is entitled Method and Apparatus for Accessing and Treating the Facet Joint; U.S. Provisional Application 61/169,601, which was filed on Apr. 15, 2009 and is entitled Facet Joint Implants and Delivery Tools; U.S. Non-provisional application Ser. No. 12/455,814, which was filed on Jun. 5, 2009 and is entitled Facet Joint Implants and Delivery Tools; and U.S. Non-provisional application Ser. No. 12/559,193, which was filed on Sep. 14, 2009 and is entitled Cervical Distraction/Implant Delivery Device. 
     Referring now to  FIGS.  1 - 28   , a first embodiment of a tool and an implant is shown.  FIG.  1    shows the tool  100  in position posterior to the spine  102 . The tool  100  includes a delivery device  104 , a decorticator  106 , and a chisel  108 . 
     The delivery device  104  may include a receiving assembly  110  at a proximal end, anchoring forks  112  at a distal end, and a generally tubular shaft  114  defining a longitudinal axis and extending between the receiving assembly  110  and the anchoring forks  112 . The tubular shaft  114  may have an annular shaped cross-section with an inner radius and an outer radius, where the difference between the two radii defines a thickness of the tubular shaft  114 . 
     The receiving assembly  110  of the delivery device  104  may have a generally conical outer surface defining a generally hollow volume or solid mass. The conical outer surface may have a longitudinal axis that coincides with that of the tubular shaft  114 . The conical outer surface may be defined by a first radius at a proximal end and a second radius at a distal end. Where the tubular shaft  114  and the receiving assembly  110  are manufactured as one piece, the second radius may match the outer radius of the tubular shaft. Alternatively, the distal end of the receiving assembly  110  may be adapted for a press fit over the proximal end of the tubular shaft  114 . The receiving assembly  110  may also include a longitudinally extending bore  116  having an inner radius matching that of the tubular shaft  114  or may have a conically shaped inner surface leading to the tubular shaft  114 . The receiving assembly  110  may also include a relatively thin annular ring  118  offset from its distal end by two relatively thin extension elements  120 . The space between the proximal end of the conical portion of the receiving assembly  110  and the distal end of the annular ring  118  may define an access opening  122 . 
     In another embodiment as shown in  FIGS.  6 A- 6 C , a receiving assembly  111  may not include the annular ring  118  and the extension elements  120 , but may remain generally conical and may include the longitudinally extending bore  116 . In addition, near the proximal end of the receiving assembly  111 , seating recesses  119  may be included. These recesses  119  may be positioned on opposing sides of the bore  116  and may recess into the proximal end of the receiving assembly  111  and the inner surface of the bore  116 . These recesses may function to receive positionally matched protrusions from any one or all of the devices being inserted into the deliver device. As such, the recesses  119 , may allow for orienting the devices properly relative to the forks  112  positioned in the facet joint. It is noted that any number of recesses may be provided and that any orientation may be used, either symmetrical or non-symmetrical, such that one or several orientations may be controlled. That is, an asymmetrical arrangement may allow for only one proper insertion position as opposed to the symmetrical orientation shown, which may allow for two proper insertion positions. 
     As shown in more detail in  FIG.  2   , the delivery device  104  may include two anchoring forks  112  formed by coping two opposing portions of the distal end of the tubular shaft  114 . The forks  112  may have a generally V-shaped tip  124  at their distal end and may have a generally rectangular cross-section extending from the V-shaped tip  124  to the proximal end of the forks  112 . The rectangular cross-section may have an inside face and an outside face where the inside face faces the longitudinal axis of the delivery device  104 . The rectangular cross-section may also have opposing surfaces connecting the inside face to the outside face and completing the rectangular cross-section. At the proximal end of the forks  112 , as suggested by the coping mentioned above, the cross-section may gradually change from rectangular to a shape matching that of half of the annular shape of the tubular shaft portion. The forks  112  may also include serrations or teeth along the opposing surfaces to assist with anchoring the delivery device  104 . 
     Referring again to  FIG.  1   , the chisel  108  may have a generally cylindrical cross-section forming a shaft  128 . The shaft  128  may have a radius substantially equal to the inner radius of the tubular shaft  114  portion of the delivery device  104  allowing for slidable insertion of the chisel  108  within the delivery device  104 . The chisel  108  may include a basic single or doubly chamfered tip  130  at a distal end or may have a coped distal end. 
     The chisel  108  may also include a head  132  at a proximal end. The head  132  may be a generally solid material and may have a generally flat distal face and a spherically shaped proximal face. The shaft  128  and tip  130  portion of the chisel  108 , measured from the distal face of the head  132  to the distal end of the chamfered tip  130 , may have a length substantially equal to the distance from a proximal face of the annular ring  118  of the delivery device  104  to the distal tip of the delivery device  104 . 
     In another embodiment, the chisel  108  may include a longitudinal lumen  131  as shown in  FIG.  1 A . While not shown, this embodiment may also include the head  132  shown in  FIG.  1    and the lumen  131  may extend there through. The lumen  131  in the chisel  108  may be used for advancing a scope along with the chisel  108  to properly place the chisel  108  and the delivery device  104 . The lumen  131  may also be used to provide suction or fluid flushing to the surgical site to remove or flush debris created by inserting the serrated forks  112  of the delivery device  104  and the tip  130  of the chisel  108 . 
     As shown in  FIG.  3   , the tip  130  of the chisel  108  may have a coped shaped similar to that of the forks  112  of delivery device  104 . In this condition, the tip  130  may include a generally V-shaped distal end matching that of the forks  112 . The tip  130  may have a width substantially equal to twice the inner radius of the tubular shaft  114  of the delivery device  104  such that the tip  130  extends between the two inside faces of the forks  112 . 
     Referring again to  FIG.  1   , the decorticator  106  may have a tubular shaft  134  portion, an abrasive distal end  136 , and a handle  138  at a proximal end. The tubular shaft  134  may have an inner radius substantially equal to the outer radius of the tubular shaft  114  of the delivery device  104  and may allow for sliding movement of the decorticator  106  along the length of the delivery device  104  and rotationally around the delivery device  104 . The abrasive distal end  136  may include serrated teeth as shown, or may include a more flat annular surface with a gritty surface. The handle  138  may have a generally cylindrical portion with randomly or patterned raised portions or recesses adapted to assist gripping the handle. The proximal and distal ends of the handle  138  may be generally spherical. It is noted that the decorticator  106  may alternatively be separate from the delivery device  104  and may be slidably inserted within the delivery device  104  as shown in  FIG.  4   . In this embodiment, the decorticator  106  may be inserted, advanced to the implantation site, and rotated similar to the decorticator  106  described above to roughen the bone surface. 
     In still another embodiment, a decorticator  106  may take the form of a relatively sharp pick, as shown in  FIG.  6 A- 6 C . As shown in  FIG.  6 A , the decorticator  106  may include a control handle  139  for advancing and pivoting the device. The control handle  139  may be connected to a tubular shaft  135 , which may be connected to a sharp flexible tip  137 . As shown, the tip  137  may be relatively thin and may have a neutral position relative to the longitudinal axis of the delivery device  104  so as to position the tip  137  within the boundary defined by the inner surface of the delivery device  104 . As such, when inserted in the delivery device  104 , the tip  137  may slide readily through the delivery device  104 . When the decorticator  106  is advanced to the distal end of the delivery device  104 , the tip  137  may be rotated and maneuvered to decorticate the surface of the lateral mass. It is noted that the shaft  135  may be relatively narrow when compared to the inner bore of the delivery device  104  to facilitate better maneuverability of the tip of the decorticator as it extends out the end of the deliver device. The decorticator may be used as shown in  FIGS.  6 B and  6 C  to rotationally scrape or longitudinally penetrate the lateral mass of a facet joint. A driving member may be used to assist the decorticating process. 
     Referring now to  FIG.  5   , the tool  100  is shown with the chisel  108  fully inserted into the delivery device  104  such that the distal face of the head  132  of the chisel  108  is in abutting relationship with the annular ring  118  of the receiving assembly  110  on the delivery device  104 . The distal tip  130  of the chisel  108  thus extends to the distal end of the delivery device  104 . A hammer  140  is shown for use in tapping the proximal end of the chisel  108  and thus advancing the forks  112  of the delivery device  104  and the tip  130  of the chisel  108  into the facet joint. As the chisel  108  and the delivery device  104  are advanced into the joint, the forks  112  of the delivery device may channel into the fact surface and displace or remove tissue. In some embodiments, this may be removed by a suction lumen in the chisel. Once the chisel  108  and delivery device  104  are tapped into place, the chisel  108  may be removed and the serrations on the opposing surfaces of the forks  112  may aid in anchoring the delivery device  104  in the joint and preventing dislodgement. 
       FIG.  6    shows the decorticator  106  in an advanced position along the length of the delivery device  104  such that the distal end is in contact with the bone surfaces surrounding the facet joint. The handle  138  is being used to rotate the decorticator  106  around the perimeter of the delivery device  104  to roughen the associated bone surfaces. Alternatively, either of the internal decorticators shown in  FIG.  4  or  6 A- 6 C  may be used. 
       FIG.  7    shows the decorticator  106  retracted and also shows the resulting roughened bone surfaces. 
     Referring now to  FIG.  8   , the tool  100 , including the delivery device  104  and retracted decorticator  106 , is shown lodged in a facet joint. Also shown is a driver assembly  142  portion of the tool  100 . The driver assembly  142  includes a distractor knob  144 , an implant shaft  146 , implant holding arms  148 , an implant distractor  150 , and an internal actuator  152  (not shown). The driver assembly  142  shown is holding an implant  154  and is poised for insertion into the delivery device  104 . 
     Referring now to  FIGS.  9 - 15    several views of the driver assembly  142  are shown. In  FIG.  9   , a portion of the delivery device  104  is shown for receiving the driver assembly  142 . The distal end of the driver assembly  142  is also shown.  FIG.  10    shows a close-up view of the distal end of the driver assembly  142  where the implant  154 , the implant distractor  150  and the internal actuator  152  are not shown. As shown, the implant shaft  146  of the driver assembly  142  defines a longitudinal axis thereof and has a generally annular cross-section with an inner radius and an outer radius where the difference between the two radii defines the wall thickness of the shaft  146 . The outer radius of the implant shaft  146  is substantially equal to the inner radius of the tubular shaft  114  of the delivery device  104 . The implant shaft  146  also includes a keyway feature  156  for preventing relative rotation between the tubular shaft  114  of the delivery device  104  and the implant shaft  146  of the driver assembly  142  when inserted. As shown, the keyway feature  156  may include a pair of tabs on opposing sides of the implant shaft  146  for engaging with a corresponding longitudinal slot in the inner surface of the tubular shaft  114  of the delivery device  104 . In another embodiment, this keyway feature  156  may be in the form of a longitudinal slot in the outer surface of the implant shaft  146  of the driver assembly  142 , as shown in  FIG.  11   , which may receive an internal ridge, tab, or other protrusion from the inner surface of the tubular shaft  114  of the delivery device  104 . 
     With continued reference to  FIG.  10   , two arms  148  are shown extending from the distal end of the implant shaft  146 . The arms  148  may be formed by coping opposing surfaces of the implant shaft  146 . As shown, the arms  148  have a generally rectangular cross-section with an inside face facing the longitudinal axis of the implant shaft  146  and an opposite outside face. The inside and outside faces of the cross-section are connected by two opposing faces. The arms  148  may include an engagement feature  158  at a distal end for engaging an implant  154 . As shown, the engagement feature  158  may include a generally rectangular element positioned orthogonal to the arms  148  and flush with the outside face of the arms. As shown in  FIG.  9   , the implant  154  may slide over the distal end of the arms  148  and may include a receiving feature  160  for receiving the engagement feature  158  of each of the arms  148 . 
     Referring now to  FIG.  11   , another embodiment of the arms  148  is shown in relation to an implant  154 . In this embodiment, the arms  148  may still be formed by coping opposing surfaces of the implant shaft  146 . In this embodiment, the outside face of the arm  148  may be a continuation of the outside surface of the implant shaft  146 . However, the inside face of the arm  148  is more detailed than that of the embodiment shown in  FIG.  10   . That is, as shown in  FIG.  11   , the inside surface may include a longitudinal ridge  162  extending the length of the arm  148 . The arm  148  may also include a bull nose engagement feature  158  extending transverse to the longitudinal axis of the implant shaft  146  along the inside face of the arm  148 . As shown in  FIG.  12   , where the arms  148  are engaged with and holding the implant  154 , the longitudinal ridges  162  of each arm  148  are positioned between upper and lower planar members of the implant  154  and the bull nose engagement features  158  are positioned in the U-shaped receiving feature slots  160  on the lateral edges of the implant  154 . 
     The implant distractor  150  is shown in  FIG.  9    and a close-up view is shown in  FIG.  14   . The implant distractor  150  may be a generally narrow conical element tapered to a point at a distal end. At a proximal end, the implant distractor  150  is shown to include an extruded hexagon shape  164 . In the present embodiment, the outer surface of the implant distractor  150  includes a continuous coil-shaped thread feature  166 . The implant distractor  150  is shown positioned proximal to the implant  154  and engaged by the internal actuator  152 . Those of skill in the art will understand and appreciate that the implant distractor  150  may take on a variety of shapes and sizes other than that shown in the present embodiment. For example, the implant distractor  150  may be a triangular shaped wedge, a generally conical shape without threads, or other shape adapted to cause separation and distraction of a facet joint. 
     Referring again to  FIG.  9   , the internal actuator  152  is visible extending from the distal end of the implant shaft  146 . The internal actuator  152  generally includes a longitudinal shaft positioned within the driver assembly  142 . The internal actuator  152  may have a radius substantially equal to the inner radius of the driver assembly  142  and may be adapted for slidable longitudinal and rotational movement relative to the driver assembly  142 . The internal actuator  152  may be moved relative to the implant shaft  146  longitudinally, rotationally, or both via the distractor knob  144  and may cause a corresponding motion of the implant distractor  150 . As such, the internal actuator  152  may advance the implant distractor  150  into the implant  154  thus expanding the implant  154  in the joint causing distraction of the joint. The distal end of the internal actuator  152  may include a hex driver type tip as most clearly shown in  FIG.  15    for engaging the extruded hexagonal shaped proximal end of the implant distractor  150 . Those skilled in the art will understand and appreciate that several driving engagements are known in the art including flat screwdriver types, phillips head types, square drive, etc. and that these are within the scope of the invention. 
     In one embodiment, when the driver assembly  142  is inserted, it may carry the internal actuator  152 , the implant distractor  150 , as well as the implant  154  with it. However, to properly position the driver assembly  142  and the implant  154 , some force may be required via a mallet or other member driving member. In this embodiment, the internal actuator  152  may be slightly isolated from the driver assembly  142 , so as to avoid advancing the internal actuator  152 , and thus the implant distractor  150 , when forcing the driver assembly  142  into the joint. This isolation may help to avoid inadvertently advancing the internal actuator  152  and the implant distractor  150 , thus avoiding inadvertent distration prior to proper placement. The isolation of the internal actuator  152  from the driver assembly may take the form of a loosely fitting threaded engagement between the driver assembly  142  and the internal actuator  152 . Alternatively, this isolation may be in the form of a clip between the two features. 
     For a detailed discussion of an implant  154  according to certain embodiments, reference is now made to  FIGS.  16 - 24   . 
     As can be understood from  FIGS.  16  and  17   , the implant  154  may include upper  168  and lower  170  members. The members  168 ,  170  may be generally planar and may also be generally rectangular. As most clearly shown in  FIG.  18   , each of the upper  168  and lower  170  members may include a proximal edge  172 , a distal edge  174 , and a pair of parallel lateral edges  176  extending longitudinally between the distal edges  174  and the proximal edges  172 . The distal  174  and proximal edges  172  may be generally square edges, while the lateral edges  176  may be defined by a radiused curve. 
     As shown in cross-section in  FIG.  19   , the inner surface  178  of the upper  168  and lower  170  member may be generally flat as it approaches the lateral edge  176 . Gradually, the inner surface  178  departs from generally flat and follows a radiused curve until it intersects with the outer surface  180 . The members  168 ,  170  may be joined at their respective distal edges  174  by a U-member  182  to form a leading end. Alternatively, as shown in  FIGS.  23  and  24   , the leading end may be formed via a weld (not shown) that couples the distal edges  174  of the planar members  168 ,  170  together. In yet another embodiment, the upper  168  and lower  170  members may be formed from a single plate bent to create the implant as shown in  FIGS.  23 A and  24 A . In any or all of these embodiments, the planar members  168 ,  170  may be biased by the leading end to be generally parallel to each other, the inner faces  178  of the planar members  168 ,  170  facing each other in an opposed fashion and abutting or nearly abutting each other. A guide feature  184  may be included on each of the upper  168  and lower  170  members as well as teeth  186  projecting outwardly from the outer faces  180  of the members  168 ,  170 . The receiving features  160  mentioned above with respect to  FIGS.  11  and  12    may also be included. Threaded slots  188  may also be included in each planar member  168 ,  170  for receiving the coil-shaped thread feature  166  on the implant distractor  150 . 
     With continued reference to  FIGS.  16  and  17   , the guide feature  184  may take the form of a half-conical feature and may be positioned at or near the proximal edge  172  of each of the upper  168  and lower  170  members. The half-conical feature may begin at the proximal edge  172  with the widest radius of the half-conical feature and may taper to a zero or approximately zero radius as the half-conical feature extends in the direction of the distal edge  174 . Where the upper  168  and lower  170  members are in parallel position, the half conical features may oppose one another and function to receive and guide an advancing implant distractor  150 . As such, like the upper  168  and lower  170  members described above, the half-conical features may also include threaded slots  188  for receiving the coil-shaped thread feature  166  on the implant distractor  150 . In other embodiments, the half-conical feature may not actually be a full half cone. Instead, the proximal end of the feature may be a segment of a circle and the feature may be relatively subtle in the form of a cone segment. In another embodiment the guide feature  184  may include a V-shaped notch or a rectangular notch in the proximal end of the upper  168  and lower  170  members as shown in  FIGS.  16 A and  18 A  and  FIGS.  16 B and  18 B  respectively. Those skilled in the art will understand and appreciate that other shaped notches or elements may be positioned on proximal end of the upper  168  and lower  170  members to guide the implant distractor  150 , and these elements are within the scope of the present disclosure. 
     As shown, the upper  168  and lower  170  members may also each include teeth  186  projecting outwardly (e.g. a direction opposite the position of the other upper or lower member) from the outer surfaces  180  of the upper  168  and lower  170  members. As shown in  FIG.  17   , the teeth  186  may be equally spaced along each lateral edge  176  and may have a linearly sloped distal face  190  and a proximal face  192  oriented orthogonally to its respective upper  168  or lower  170  member. The distal face  190  and proximal face  192  may intersect to form a point  194 . The teeth  186  may also be bounded by opposing inside  196  and outside  198  lateral faces separated by a thickness approximately equal to the thickness of the upper  168  and lower  170  members. As shown in  FIG.  19   , the outside face  198  of the teeth  186  follows an extension of the radiused curve formed by the inner surface  178  of the upper  168  or lower  170  member at the lateral edge  176 , this curve being referred to as a first radiused curve. Additionally, the inside face  196  of the teeth  186  follows a second radiused curve offset from the first radiused curve, such that the teeth  186  have a generally constant thickness from the location where they depart from the outer surface  180  of the upper  168  or lower  170  member to the point  194 . The radiused shape of the teeth  186  allows the implant  154  to slidably engage the inside of the delivery device  104  when it is advanced toward the implantation site. Those skilled in the art will understand and appreciate that one, as opposed to both, of the upper  168  and lower  170  members may include teeth  186  to facilitate freedom of motion of the facet joint once the implant  154  is in place. 
     As shown in  FIGS.  16  and  17   , where a U-member  182  is used to connect the upper  168  and lower  170  members, the U-member  182  may overlap the upper  168  and lower  170  members. Alternatively, as shown in  FIG.  20   , the U-member  182  may attach to the distal ends  174  of the upper  168  and lower  170  members via a butt joint. In either case, the U-member  182  may be fastened via welding, fusing, or other techniques known in the art. As shown in  FIGS.  21  and  22   , the U-member  182  may be a relatively thin, generally rectangular piece of material formed into the shape of the letter if. The rectangular piece of material may have a length defined by the amount of overlap of the upper member  168  and the lower member  170  in addition to the length associated with hairpin or U portion of the member  182 . The width of the rectangular plate may be substantially equal to the distance between the teeth  186  of the upper  168  and lower  170  members. The U-member  182  may be adapted to provide the parallel biased position mentioned and yet allow distraction of the upper  168  and lower  170  member when a separation force is applied, the proximal edge  172  of the upper  168  and lower  170  member distracting more than the distal edge  174 . 
     As shown in  FIGS.  23  and  24   , where the distal edges  174  of the upper  168  and lower  170  member are joined via welding, the distal edges  174  may include a notch to facilitate more weld length and to cause flexure to occur in the upper  168  and lower  170  members rather than in the weld itself. Also shown in  FIGS.  23  and  24    are the U-shaped receiving feature slots  160  for receiving the bull nosed engagement features  158  of the arms  148  of the driver assembly  142 . As shown most clearly in  FIG.  24   , the U-shaped receiving feature slots  160  are positioned between the equally spaced teeth  186  and extend into the lateral edges  176  of the upper  168  and lower  170  member just beyond the inside edge of where the teeth  186  begin extending from the outer surfaces  180 . 
     The receiving feature  160  may take several forms including a rectangular notch in the lateral edge  176  of the upper  168  and lower  170  member or a U-shaped notch. The receiving feature  160  may be adapted to receive an engagement feature  158  positioned on the arm  148  of the driver assembly  142 . The receiving feature  160  may be any shaped recess and may be adapted to be engaged by the engagement feature  158  so as to prevent or limit relative longitudinal motion between the arms  148  and the implant  154 , when the implant  154  is in the neutral position. However, when in an expanded or distracted position, the receiving features  160  may be such that they are lifted free of the engagement feature  158  of the arms  148 , thus allowing relative longitudinal motion between the driver assembly  142  and the implant  154 . 
     The driver assembly  142  and implant  154  described with respect to  FIGS.  8 - 24   , may be used to distract a facet joint. With the delivery device  104  positioned as shown and described with respect to  FIG.  7   , the implant  154  may be positioned to be held by the arms  148  of the driver assembly  142 . The driver assembly  142  and implant  154  may then be inserted into the delivery device  104  and slidably advanced such that the implant  154  is positioned between the forks  112  of the delivery device  104  and within the facet joint. The advanced position of the driver assembly  142  and implant  154  within the delivery device  104  may be most clearly seen in  FIG.  13   . The proximal end of the driver assembly  142  may be tapped on to fully advance the driver assembly  142  and properly position the implant  154 . The implant shaft  146  of the driver assembly  142  may be prevented from rotating by the keyway feature  156  securing it against relative rotation with respect to the delivery device  104 . As such, once positioned, the distractor knob  144  of the driver assembly  142  may be turned, as shown in  FIG.  25   , thereby advancing the internal actuator  152  and further advancing the implant distractor  150 . In the embodiment described, the coil-shaped thread feature  166  on the implant distractor  150  may engage the threaded slots  188  of the half-conical features  184  of the upper  168  and lower  170  members of the implant  154 . As such, the implant distractor  150  may be guided and remain in position to further engage the threaded slots  188  on the upper  168  and lower  170  members. As the implant distractor  150  continues to advance, those of skill in the art will understand and appreciate that its tapered shape advancing between the upper  168  and lower  170  members will force the upper  168  and lower  170  members of the implant  154  apart causing them to pivot about a point defined by the attachment to each other at their distal ends  174 . As the implant  154  continues to be distracted, the upper  168  and lower  170  members of the implant  154  are laterally separated such that they clear the engagement features  158  on the arms  148  of the driver assembly  142 . As shown in  FIG.  26   , when the implant distractor  150  has been fully advanced and the implant  154  is in place, the driver assembly  142  may be slidably removed from the delivery device  104  leaving behind the implant distractor  150  and the implant  154 . 
       FIG.  27    shows yet another device, the device being adapted for placing bone paste over the implant  154  in the joint. An injector  202  is shown and includes a syringe type cannula  204  with a closed distal end  206  and two exit doors  208  positioned on opposite sides of the distal end  206  of the cannula  204 . The cannula  204  includes a plunger  210  with a seal and further includes a stopping disc  212  at its proximal end, the plunger  210  penetrating the stopping disc  212  and having a handle  214 . The cannula  204  may have an outer radius substantially equal to that of the inner radius of the delivery device  104  to allow for slidable engagement of the two devices. The disc  212  at the proximal end is generally flat and is adapted to engage the receiving assembly  110  of the delivery device  104  and provide a stop point for the injector  202  when inserted into the delivery device  104 . As shown, the cannula  204  may contain a bone paste material in a liquid form. 
     As shown in  FIG.  28   , the injector  202  may be inserted into the delivery device  104  and slidably advanced such that the distal end  206  is near the implantation site and the disc  212  abuts the annular ring  118  of the receiving assembly  110  of the delivery device  104 . The injector  202  may be rotatably positioned such that the doors  208  are positioned to open perpendicular to a line connecting the distal ends of the forks  112 . The disc  212  may include tabs  216  for such positioning relative to the annular ring  118  on the receiving assembly  110 . Once in position, the plunger  210  may be actuated to compress the bone paste material creating an internal pressure which forces the exit doors  208  open allowing the bone paste to escape and flow over the implantation site. 
     The above description has included some references to use to allow for a better understanding of the structure. Below is a more detailed discussion of that use including the devices and techniques for distracting and retaining a facet joint in a distracted and forwardly translated condition. The implantation procedure may be performed under conscious sedation in order to obtain intra-operative patient symptom feedback. 
     Initially an incision may be made in the patients back. Tools known in the art may be used to create this incision and to open an access path through the tissues of the back to access the spine. Once an access path is created, the chisel  108  described above may be inserted into the delivery device  104  and the two of them may be inserted through the incision and the distal tip  130  may be positioned adjacent the target facet joint. It is noted that visualization may be provided by first inserting a scope down the delivery device  104  rather than the chisel  108 . Additionally, an incision in the facet joint capsule may be made prior to beginning the procedure, and thus prior to insertion of the chisel  108 . Once the distal tip of the delivery device  130  is properly positioned adjacent the facet joint and any other preparation steps are completed, the chisel  108  may be inserted. Once the chisel  108  and delivery device  104  are properly positioned, the head  132  of the chisel  108  may be tapped with a driving device  140  such as a hammer or other instrument to advance the distal tip  130  of the chisel  108  and the forks  112  of the delivery device  104  into the facet joint. Once the delivery device  104  is properly positioned, the chisel  108  may be removed. At this point, the implant  154  may be placed in the driver assembly  142  and the implant  154  and driver assembly  142  may be slidably advanced through the delivery device  104 . The forks  112  of the delivery device  104  may be holding the facet joint slightly distracted. As such, the implant  154 , in its flat and parallel position, may slide relatively easily into the facet joint. To the extent that it does not, the proximal end of the driver assembly  142  may be tapped to properly advance and position the implant  154 . Once properly positioned, the distractor knob  144  on the driver assembly may be rotated or otherwise actuated to activate the internal actuator  152 . The internal actuator  152  advances the implant distractor  150  into the implant  154  and thus distracts the implant  154 . It is noted here that the distraction of the implant  154  may cause the upper  168  and lower  170  member of the implant  154  to clear the engagement features  158  of the holder arms  148  thus allowing the driver assembly  142  to be freely removed from the delivery device  104  leaving the implant  154  and the implant distractor  150  behind. The injector  202  may then be advanced through the delivery device  104  and positioned to allow the doors  208  to open in a direction approximately perpendicular to the forks  112  of the delivery device  104 . The handle  214  may be depressed thus advancing the plunger  210  and ejecting the bone paste or other anchoring material. The injector  202  may then be removed. The delivery device  104  may also be removed and the incision closed. 
     Those skilled in the art will understand and appreciate that several modifications or variations from the above the identified embodiments may be made while still falling within the scope and spirit of the present disclosure. For example, several alternative actuation mechanisms at the proximal end of the tool for actuating the distracting elements of the tool may be available. Additionally, several alternative implants may be available. For example, as shown in  FIGS.  29  and  30   , an implant  218  similar to that previously described is shown and includes a body  220  and a screw  222 . The body  220  includes an upper  224  and lower  226  face joined together at a leading end  228  and separated from each other at a trailing end  230 . 
     As shown in  FIG.  29   , when the screw  222  is not received in the body  220 , the upper  224  and lower  226  faces may reside against each other such that the body  220  is generally flat. As shown in  FIG.  30   , when the screw  222  is received in the body  220 , the upper  224  and lower  226  faces may be separated from each other, the degree of separation increasing as the screw  222  is increasingly received in the body  220 . As the upper  224  and lower  226  faces are separated from each other, the body  220  takes on more of a wedge shape, with the leading end  228  being the narrow end of the wedge and the trailing end  230  being the wide end. The faces may include teeth  232  and the trailing end  230  of the upper face  224  may be formed to project towards the leading end, both of these features assisting in the implant  218  anchoring to the bone facet surfaces. Holes  234  may exist in the faces  224 ,  226  such that when the screw  222  is received in the body  220 , the thread edges of the screw  222  may project through the holes  234  to bite into the facet surfaces. The wedge shape of the implant  218  may facilitate anchoring the implant  218  within the facet joint and may also facilitate distraction, translation, or subluxation of the facet surfaces relative to each other. 
     As can be understood from  FIG.  29   , the collapsed and flattened body  220  may be placed between the opposing surfaces of the facet joint. The posterior or trailing end  230  of the body  220  is configured to be capable of receiving a screw, bolt, or some other inserted component  222 . As indicated in  FIG.  30   , upon insertion of the screw, bolt, etc.  222 , the body  220  begins to expand. This expansion and separation is enabled by a hinge  236  at the anterior or leading end  228  of the body  220 . As the body  220  expands, sharp directional teeth, cleats, or keels  232  on the opposing (superior &amp;inferior) surfaces or faces  224 ,  226  of the body  220  may become anchored in the cortical bone of the opposing facet surfaces. These teeth, cleats, or keels  232  may engage the facet surfaces and provide acute fixation of the body  220  within the facet joint. The teeth, cleats, or keels  232  may be included on only one surface  224 ,  226  as opposed to both surfaces  224 ,  226  so as to allow for a movement of the joint after placement of the implant  218 . 
     The distraction and separation of the facet joint via the expanded implant (see  FIG.  30   ) may increase foraminal area and reduce the symptoms associated with nerve root compression. 
     Another implant embodiment is depicted in  FIGS.  31  and  32   , wherein a screw  238  also acts to spread apart the faces  240 ,  242  of the body  244  of the implant  236 . In this embodiment, the implant  236  may have an upper  240  and a lower  242  member positioned adjacent to each other. The upper  240  and lower  242  member may be substantially rectangular with a distal edge a proximal edge and parallel lateral edges. The distal edge may be slightly radiused. The upper  240  and lower  242  members may be connected along their distal edge by a connection member  246  in the form of a triangularly bent plate or other connection. The connection member may include a penetration  248  adapted to receive an implant distractor  238 . As with the previous embodiments, the implant  236  may include teeth  250  on the outer surface of the upper member  240  or the lower member  242  or both as shown. In one embodiment, the implant  236  may be formed from a single plate and folded to create the shape shown. In use, the implant  236  may be positioned in a facet joint and the implant distractor  238  may be advanced thereby separating the upper  240  and lower  242  member and distracting the joint. Similar to that discussed above with respect to  FIGS.  29  and  30   , such an embodiment as depicted in  FIGS.  31  and  32    may have holes (not shown in  FIGS.  31  and  32   ) in the body surfaces  240 ,  242  so as to allow the threads of the implant distractor  238  to extend through the surfaces of the body  244  to bite into the facet surfaces. 
       FIGS.  33  and  34    depict isometric views of another implant  248  with V-shaped members  250  residing on a threaded bolt  252  between an anterior threaded block  254  and a posterior non-threaded block  256 . The V-shaped members  250  may slidably engage the bolt  252  As shown in  FIG.  33   , the V-shaped members  250  are in a non-expanded state and are spaced apart from each other along the length of the bolt  252 . The implant  248  may be inserted into the facet joint in the non-expanded state depicted in  FIG.  33   . As can be understood from  FIG.  34   , the bolt  252  may be rotated to cause the anterior threaded block  254  to travel along the bolt  252  towards the posterior non-threaded block  256 . It is noted that in use, the rotation of the blocks  254 ,  256  may be prevented by their position within a facet joint, thus causing the anterior threaded block  245  to travel rather than rotate when the bolt  252  is rotated. The posterior non-threaded block  256  may be in abutting position against the head  258  of the bolt  252  thereby preventing it from moving away from the anterior thread block  254 . Thus, as the anterior threaded block  254  advances toward the posterior non-threaded block  256 , the V-shaped members  250  are squeezed together. As the V-shaped members  250  are increasingly squeezed together between the blocks  254 ,  256 , the V-shaped members  250  are increasingly expanded outward, thereby biting into the facet joint surfaces to anchor the implant  248  in the facet joint and distract, translate and/or subluxate the facet surfaces relative to each other. 
       FIGS.  35 - 36  and  37 A -D, depict isometric views of another implant  260  with planar plates or leaves  262  residing on a threaded bolt  264  and parallel shafts  266  between an anterior threaded block  268  and a posterior non-threaded block  270 . As shown in  FIG.  35   , the planar plates  262  are in a skewed non-expanded state and are spaced apart from each other along the length of the bolt  264  such that may lie generally flat or, more specifically, at approximately 45 degrees on the bolt  264  and shafts  266 . The plates  262  may include a slotted hole for receiving the bolt  264 , which allows for the position described. The implant  260  may be inserted into the facet joint in the non-expanded state depicted in  FIG.  35   . As can be understood, the bolt  264  may then be rotated to cause the anterior threaded block  268  to travel along the bolt  264  towards the posterior non-threaded block  270 , thereby causing the planar plates  262  to squeeze together. As the planar plates  262  are increasingly squeezed together between the blocks  268 ,  270 , the planar plates  262  are increasingly expanded outward or, more specifically, are caused to be generally perpendicular to the bolt  264  and shafts  266 . As a result, the planar plates  262  bite into the facet joint surfaces to anchor the implant  260  in the facet joint and distract, translate and/or subluxate the facet surfaces relative to each other. 
       FIGS.  37 A-D  show an embodiment, which combines features of the embodiment shown in  FIGS.  33  and  34    with features of the embodiment shown in  FIGS.  35  and  36   . 
       FIGS.  38 A-C  shows another embodiment of an implant  272 . The implant  272  may include two stacked structures  274  that interface along a plane  276 . Each structure  274  may include opposing ratchet teeth  278  along the plane. The position and orientation of the ratchet teeth  278  may be such that relative translation between the two structures  274  is allowed when a force is applied to each structure  274  in opposing directions. That is, once the implant  272  is properly positioned within the facet, a device may be use to apply a force to the superior structure  274  which causes forward translation of that structure  274  relative to the inferior structure  274 . The ratchet teeth  278  on the superior structure  274  may slide up the slope of the teeth  278  on the inferior structure  274  until opposing apexes of teeth  278  pass by each other causing the two structures  274  to nest in a new relative position, the displacement being equal to the length of the teeth  278 . Each structure  274 , or only one of the structures  274 , may increase in thickness along its length, such that continual relative ratcheted displacement creates a greater overall thickness. The increasing thickness of the implant structures  274  may cause distraction and forward translation in the facet joint. The opposing facet surfaces may be separated and the superior vertebra may be pushed anterior relative to the inferior vertebra. In addition, anchoring teeth  280  may be provided on the outer surface of both structures  274  of the implant  272  to provide acute fixation to the articular surfaces. The implant  272  may be configured in a number of different shapes including, but not limited to, a wedge, a double wedge, a rectangular box, and “v” shaped. 
       FIGS.  39 A-D  show another embodiment of an implant  282 . In this embodiment, a screw like implant  282  may be inserted between the facet. The insertion of this screw may serve to distract the joint surfaces resulting in a decompression of the nerve root. Additionally, the threads  284  of the screw may include V-shaped notches  286  in the threads  284  spaced throughout the length of the screw creating serrated teeth. As the screw implant  282  is threaded progressively further anterior, the serrated teeth may cut/bore into the cortical bone of the opposing facet surfaces. The defect in the bone these serrations produce may prevent the implant  282  from backing out posteriorly or migrating medial/lateral because the threads  284  are configured with the serrated teeth to allow the implant  282  to catch or “bite” in the bone if any posterior withdraw or backing out occurs. Additionally or alternatively, as shown in  FIGS.  40 A-C , the screw threads  284  may include a leaf spring  288  to maintain friction of the threads  284  against the newly cut threads in the bone thereby preventing the screw from backing out. 
       FIGS.  41 A-D  show another embodiment similar to the one shown in  FIGS.  39 A-D . That is, in this embodiment, the implant  290  may take the form of a screw, but the threads  292  of the screw may have a T-shaped profile as shown in  FIG.  41 D . In addition, the flat surface of the T-shaped profile may define a diameter at any given point along the length of the screw. In one embodiment, the diameter may increase over the length of the screw and not be limited to just the tip like a traditional screw. As such, when the implant  290  is placed, the more it is advanced into the facet joint, the more separation it creates. 
       FIGS.  42 A-F  show another embodiment of an implant  294 . In this embodiment, the implant  294  may again take the form of screw. The screw may have a washer or extra broad head  296  with sharp protrusions  298  on the distal surface of the head  296  that engage the superior and inferior lateral mass surfaces as the screw is inserted into the facet joint. The engagement of the sharp protrusions  298  may occur as a result of both the longitudinal translation of the screw together with the rotational motion causing the sharp protrusions  298  to cut into the lateral mass surface as the screw is advanced and rotated. As the washer  296  rotates, the sharp protrusions  298  roughen the lateral masses and create a fracture environment. This fracture environment causes osteoblastic activity that will lead to bone production and assist in fusion of the joint at the lateral mass. Moreover, the moat created by the rotating and cutting protrusions  298  may begin to lock the facet surfaces together. 
     In the present embodiment, the protrusions  298  may be tab like and cut relatively deeply into the lateral mass. In addition as shown in  FIGS.  42 D-F , the tabs may position themselves as shown where the superior tab is flared to engage the lateral mass and the inferior tab is wedged into the joint. In this configuration, the tabs may act to further distract the joint beyond that provided by the diameter of the screw portion of the implant. In other embodiments, as shown in  FIGS.  43 A-C , the sharp protrusions  300  may be sharp prongs or spurs adapted to roughen the surface. 
       FIGS.  44 A-D  show another embodiment of an implant  302 . In this embodiment, a facet distraction implant  302  has a floating collar  304  for use with a screw type implant. As shown, the collar  304  may be positioned to pivot about the head  306  of the screw due to the spherical shaped head  306  on the screw in a ball and socket fashion. The floating collar  304  allows the screw implant to accommodate irregular, non-planar surfaces of the lateral mass and may aid in the prevention of reverse threading of the implant  302  once the screw has been advanced to the proper position within the facet. As shown, the screw may be implanted to provide distraction and forward translation of the joint. The floating collar  304  may include teeth or spikes  308  that roughen/decorticate the cortical bone of the superior and inferior lateral masses resulting in the creation of a fracture environment. This may improve the chance of posterior lateral mass facet fusion. 
       FIGS.  45 A-D  show yet another embodiment of a decorticating screw type implant  310 . 
       FIGS.  46 A-D  show another embodiment of an implant  312 . In this embodiment, a structural implant  312  is inserted between the opposing surfaces of a facet joint. This implant  312  may be in the form of a screw as described above or may be a different implant requiring a torque or other force to be applied to anchor the implant  312  in the facet joint. As shown, when the implant  312  is inserted increasingly more anterior within the facet, a torque limiting mechanism  314  within the device may measure the force or torque applied to the system. Once a predetermined value of torque or force is achieved, the distal end of the system may detach causing the implant  312  to become a permanent distraction implant. 
     In the case of a screw implant, the torque limiting mechanism  314  may be a necked down portion of the device creating a calibrated weakened portion intended to fail when a specified torque is exceeded. 
     In this embodiment, the implant  312  may also include a number of anti migration features to prevent backout. These features may include directional teeth, roughened surfaces, keels, spikes, or other features known in the art. As with other implants, the geometry of the implant may cause distraction of the joint and lead to a more pronounced forward translation of the joint as the opposing facet surfaces separate. 
       FIGS.  47 A-B  show another embodiment of an implant  316 . In this embodiment, again a screw shaped implant  316  may be inserted into the facet to distract the facet surfaces and increase foraminal height resulting in a decompression of a symptomatic nerve root. In this embodiment, however, the implant may include two main components. First, the implant  316  may include a relatively stiff but malleable cone-shaped screw structure  318  with aggressive threads for biting into the opposing surfaces of the facet joint. These threads may have a number of variations for preventing movement of the implant after it is implanted. Second, the implant may include an inner core support member  320 . The core support member  320  may be in place when the implant  316  is placed to assist in maintaining the shape of the screw structure  318 . After placement, the core support member  320  may be removed. The malleability of the screw structure  318  may allow it to collapse slightly once the implant  316  is properly positioned and inserted. The collapsing of the screw structure  318  would change the alignment of the threads and prevent reverse threading that could lead to posterior migration. 
     Yet another embodiment is show in  FIGS.  48 A-C . In this embodiment, a superior  324  and an inferior  326  screw may be used to create an implant  322 . The two screws  324 ,  326  may have communicative threaded serrations that work in opposition to one another. As such, when the inferior screw  326  is rotated, the threads may interact with the superior screw  324  causing it to rotate in the opposite direction. Moreover, the threads on the inferior screw  326  and superior screw  324  are such that opposite direction rotation draws both screws  324 ,  326  in to the facet joint. As the screws  324 ,  326  enter the joint, the facet surfaces are distracted apart from one another and the threads of the screw bite into the facet surfaces. The opposing rotation of the two screws  324 ,  326  may also assist in preventing back out of the implant or reverse threading/unscrewing. It is noted that several configurations may be used to create the opposite rotation of the screws. In one embodiment, a housing may be placed over each screw allowing the screws to freely rotate relative to the housing, but securing the screws adjacent to one another. In this embodiment, the opposite rotation may occur due to the threads engaging with one another as described above or the screw heads may have gear teeth for engaging one another and causing opposite rotation. In another embodiment, the screws may have gears on them positioned within the housing to engage one another and cause opposite direction rotation. 
       FIGS.  49 A-C  show yet another embodiment of an implant  328 . In this embodiment, a translating system including a vertical plate  330  and a bumper  332  may be included. The superior aspect  334  of the bumper  332  may have a rounded concave surface for opposing the lateral mass of a superior vertebra. The translating system may be secured by anchoring a screw  336  to the lateral mass of an inferior vertebrae. The screw  336  may act as the foundation for a bumper system intended to push a superior vertebra forward (anterior) creating translation of the superior vertebra relative the inferior vertebra. This forward translation may create an increase in foraminal area and results in a decompression of the nerve root. The implant  328  may be configured to maintain permanent forward translation in order to prevent foraminal narrowing and nerve root compression. In addition, the implant  328  may provide rigid resistance when the superior vertebra exerts posterior translation vectors because it is anchored by the inferior lateral mass screw. The prevention of this posterior translation may keep the segment in a state of forward translation and preserve the associated increase in foraminal area. 
       FIGS.  50 A-B  show another embodiment of an implant  338 . In this embodiment, a wedge shaped or triangular implant  338  may be inserted between the face surfaces. The angled/pointed portion  340  with two acute line segments may allow the implant  338  to enter into the flat facet joint when sufficient force is applied. As the implant  338  is inserted progressively more anterior, the distraction of the opposing facet surfaces may increase. This separation results in an increase of foraminal height and decompresses the symptomatic nerve root. 
     The surfaces of this implant  338  may include teeth, spikes, cleats, surface roughening, and/or keels  342  to help prevent migration or backout. In another configuration of this embodiment, as shown in  FIGS.  51 A-B , the wedge shaped or triangular implant  338  may be anchored in position by one or two (one shown in FIG.) lateral mass screws/nails  344  that would connect the superior &amp;inferior aspects of the implant  338  to the corresponding superior &amp;inferior lateral masses of the affected segment. 
       FIGS.  52 A-C  show another embodiment of an implant  346 . In this embodiment, a distraction/translation system may include an anterior hook  348  and a posterior hook  350  joined by a threaded bolt  352 . The anterior hook  348  may be placed over the anterior aspect of the inferior facet and the posterior hook  350  may be positioned posterior to the superior facet. The anterior hook  348  may have a C-shaped profile with a lip for engaging the anterior aspect of the inferior facet. The posterior hook  350  may have a S-shaped profile with a lip for engaging the posterior aspect of the superior facet. The threaded bolt  352  may be positioned through the facet joint and may threadably engage a posterior leg  354  of the anterior hook  348  and an anterior leg  356  of the posterior hook  350  as shown. As the bolt  352  is tightened and the hooks  348 ,  350  are drawn together, they create anterior translation of the superior vertebra relative to the inferior vertebra. This translation may result in increased foraminal area and nerve root decompression. The translation is maintained through the permanent placement of the hooks and bolt. 
       FIGS.  53 A-C  show another embodiment of an implant  358 . In this embodiment, an insert  360  may be placed in the facet joint between two opposing facet surfaces. The geometry of the implant  358  could take a number of shapes including, but not limited to, rectangular, conical, triangular, or trapezoidal shape. Once the implant  358  is properly positioned, it may then be rotated some degree of rotation. This rotation may result in an increased height of the implant and cause facet surface separation and thus increased foraminal area and decompression of the symptomatic nerve root. In another configuration as shown in  FIG.  53 C , the rotated implant  358  may have outer tabs  362  that are capable of receiving a bone screw, nail, or pin that can be anchored in the superior and inferior lateral masses. These tabs  362  and anchors may assist in the prevention of implant migration leading to a reduction in the foraminal area. 
       FIGS.  54 A-C  show another embodiment of an implant  364 . In this embodiment, an implant  364  may take the form of a collapsible diamond shape  366  with an adjustment bolt  368  abutting a first corner  371  and threaded through an opposing corner  370  of the shape. The other corners  372  may include pads  374  for positioning against opposing articular faces of a facet joint. The implant  364  may be placed into the facet joint in a collapsed position and the adjustment bolt  368  may then be actuated to draw the opposing corners  371 ,  372  of the shape together thereby expanding the shape and pressing the pads  374  against the articular faces. As the shape expands, additional facet distraction is achieved resulting in an increased foraminal opening. This implant  364  may be provided in a number of geometries or materials to provide directional distraction where, for example, more distraction occurs near the posterior edge of the facet relative to the anterior edge of the facet. Additionally, the surface of the pad  374  may include teeth or keels to enable bone purchase in the facet. 
       FIGS.  55 A-C  show another embodiment of an implant  376 . In this embodiment, the implant  376  may take the form of an expandable hinged structure with an upper member  378  and a lower member  379  connected at their distal ends  380  by a hinge  382 . The implant  376  may be placed between the facet surfaces in a collapsed state. The posterior aspect of the implant  376  may include a receiving slot that is able to receive a screw, bolt, or other activation system. Engaging this slot with an activator would cause the implant  376  to expand on its hinge  382  creating distraction and translation of the joint. For example, the activator may be a wedge, a turnable flat tool, a tapered screw, or any other device that may be inserted into the receiving slot to forcibly expand the upper  378  and lower  379  members. As shown, the hinge  382  may also include a brace member  384  for maintaining the posterior halves of the hinge in a separated position. The brace member  384  may be spring loaded or otherwise engaged with the hinge halves  378 ,  379  such that when expanded the brace  384  moves into position to support the open position of the hinge  382 . In some embodiments, the upper  378  and lower  379  member of the implant  376  may have teeth, cleats, or keels  386  to engage the cortical bone of the opposing facet surfaces. These mechanisms would provide fixation of the implant  376  to the joint. 
       FIGS.  56 A-C  include another embodiment of an implant  388 . In this embodiment, a collapsed and flattened structure  390  may be placed between the opposing surfaces of the facet joint. The posterior aspect  392  of the structure  390  may be configured to be capable of receiving a screw, bolt, or some other inserted component  394 . Upon insertion of the screw, bolt, etc.  394 , the structure may begin to expand. This expansion and separation may be enabled by a hinge  396  at the anterior aspects of the structure  390 . As the structure  390  expands, sharp directional teeth, cleats, or keels  398  on the opposing (superior &amp;inferior) surfaces of the structure may become anchored in the cortical bone of the opposing facet surfaces. These teeth, cleats, or keels  398  may engage the face surfaces and provide acute fixation of the structure within the facet joint. Together with the these teeth, cleats, or keels  398 , or as an alternative to them, as shown, the proximal end of the implant  388  may also include flanges  400  that overlap the lateral mass of the facet joint. These flanges  400  may include holes  402  for anchoring the implant  388  to the superior and inferior facet masses, or to only one of the masses. In a related embodiment, the superior and inferior surfaces may have open ports  404  that enable the screw threads to exit the structure and gain purchase in the opposing facet surfaces. The distraction and separation of the joint may increase foraminal area and reduce the symptoms associated with nerve root compression. 
       FIGS.  57 A-C  show yet another embodiment of an implant  406 . In this embodiment, the implant  406  may resemble a screw and wall anchor. The wall anchor portion  408  may be generally cylindrically shaped and include two half sections  410  separated by a slot or it may include a multitude of longitudinally extending sections  410 . 
     These sections  410  may be connected together at the tip  412  as shown or they may be connected together at the proximal end  414  of the implant  406  and at the tip  412  and may include several connections along the length of the implant  406 . The implant  406  may have a sharp, triangular or conical tip  412  that allows for access into the flattened facet joint. Once the implant  406  is inserted into the facet surface, a screw, bolt, or other insertion component  416  may be inserted into the implant  406 . As this component  416  is advanced the sections  410  may expand creating additional separation of the joint and allowing for measured distraction of the space. The sections  410  of the wall anchor portion  408  may include sharp directional teeth, cleats, or keels  418  that engage the cortical bone of the opposing facet surfaces. 
       FIGS.  58 A-B  show yet another embodiment of an implant  420 . In this embodiment, a tool  422  may be used to apply a force to the superior vertebra of a motion segment. This forward translation would result in an increase in foraminal area and reduced nerve root decompression. Following the forward translation of the motion segment, an angled screw  424  would be placed through the superior facet surface, facet capsule, and inferior facet surface. This screw  424  would provide temporary immobilization of the joint which leads to fusion. 
       FIGS.  59 A-B  show yet another embodiment of an implant  426 . In this embodiment, a collapsed, triangular shaped implant is inserted into the facet. The implant  426  may include a central shaft  428  and two or more springing leaves  430 . The leaves  430  may be connected to the distal end of the shaft  428  and may extend proximally along the shaft  428 . The leaves  430  may be connected at the distal end so as to be biased in a direction to form an arrow shape. The leaves  430  may be held in the compressed state by an insertion &amp;delivery tool  432 . The delivery tool&#39;s compression of the implant  426  prevents the superior and inferior surfaces of the implant  426  from springing open to a distracted position. Once the compressed implant  426  is positioned correctly, the delivery tool  432  may be removed. Removing the tools causes the leaves  430  to open/expand causing distraction and separation of the facet joint thus resulting in increased foraminal area and reduced nerve root compression. 
       FIGS.  60 A-B  show yet another embodiment of an implant  434 . This concept has at least three embodiments. The first embodiment consists of a direction facet joint screw  436  that is advanced through an inferior facet until it makes contact with the opposing superior facet. Once the screw  436  makes contact with superior facet surface, the energy applied to advance the screw  436  results in distraction and separation of the joint due to bearing of the screw tip  438  on the underside of the superior articular surface. In one variation of this embodiment, the hole for the screw in the inferior facet may be pre-drilled. When the screw is installed and encounters the superior facet, the screw may bite into the superior facet as it forces the fact upward and distracts the joint. Alternatively, in this embodiment, the screw may have a blunt tip  438  to distract the joint without biting into the superior facet. 
     In the second embodiment, as shown, a directional facet screw  436  may be advanced through the inferior facet surface until it engages with a facet spacer/plate  440  that is inserted in between the facet surfaces within the facet capsule. As the screw  436  makes contact with the facet spacer/plate  440 , the flat surface of the spacer/plate  440  may push up against the opposing superior facet surface causes distraction and forward translation. This separation of the facet surfaces results in increased foraminal area and reduced nerve root compression. 
     In a third embodiment, the spacer/plate  440  may have a shape to allow the screw  436  to pass through a first end and the other end to be placed in the facet joint. In this embodiment, the C-shaped spacer  440  may be positioned in the joint, thereby slightly distracting the joint. The screw may then penetrate a first end of the spacer  440  thereby anchoring the spacer  440  in the joint. The screw may then be advanced through the inferior facet surface until it engages with the spacer/plate  440 . As the screw  436  makes contact with the facet spacer/plate  440 , the flat surface of the spacer/plate  440  may push up against the opposing superior facet surface causes distraction and forward translation. In some embodiments, the screw may penetrate the spacer and aid in fixing the joint. 
       FIGS.  61 A-C  show yet another embodiment of an implant  442 . In this embodiment, bracket type structures  444  may be attached to the superior and inferior lateral masses. The bracket type structures  444  may enable the attachment of a single bolt  446 . The bolt  446  may be configured to create a distraction energy. That is, it may be connected to the inferior bracket  444  to allow rotation but not relative translation. In contrast, the bolt may threadably engage the superior bracket  444 . As such, when the bolt  446  is “unscrewed” it may function to push the inferior and superior brackets  444  apart. This distraction may result in increased foraminal area and reduction in nerve root compression. 
       FIGS.  62 A-C  show yet another embodiment of an implant  448 . In this embodiment, bracket type structures  450  may each have a leg  452  for positioning within a facet joint and another leg  454  for receiving a bolt  456 . As with the bracket above, the bolt  456  may be configured to create distraction energy. That is, it may be connected to one of the superior or inferior bracket  450  so as to allow rotation but not relative translation. The other bracket  450  may threadably engage the bolt  456 . As such, when the bolt  456  is “unscrewed” it may function to push the brackets apart resulting in and increased foraminal area. 
       FIGS.  63 A-C  show yet another embodiment of an implant  458 . In this embodiment, a triangular shaped implant  458  including a bent plate and a filler wedge may be inserted in the facet joint. As the triangular implant  458  is inserted progressively more anterior, the joint may be distracted to an optimal level. Once the desired distraction is achieved, an anchoring screw  460  may be inserted through the implant  458  and into the inferior lateral mass. The superior aspect of the implant  458  may include a metal flap  462  with teeth, spikes, or cleats  464 . This malleable flap  462  may be contoured to the superior lateral mass and anchored using its teeth, spikes, or cleats  464 . The metal flap  462  and inferior screw  460  may provide permanent fixation of the triangular implant  458  to enable permanent distraction of the facet and immobilization of the joint facilitating permanent fusion of the joint. 
       FIGS.  64 A-C  show yet another embodiment of an implant  466 . In this embodiment, a distraction system consists of a central anchoring plug  468 , an initiating plate  470 , and two external plates  472 . The two external (superior and inferior) plates  472  may be attached to the lateral masses of a motion segment and may be anchored using screws. The initiating plate  470  may then be inserted in the gap  471  between the external plates  472  to initiate opening of the plates  472  and the joint and allow for further insertion of the anchoring plug  468 . Following the insertion of this initiating plate  470  and turning or manipulating the plate  470  to open the external plates  472 , the central anchoring plug  468  may then be advanced into the gap  471  between the external plates  472  causing expansion of the plates and distraction and separation of the joint. 
       FIGS.  65 A-C  show yet another embodiment of an implant  474 . In this embodiment, nitinol hooks  476  may be configured to have a memory. The hooks  476  may be flattened and inserted through a delivery system  478 . The delivery system  478  may be placed in a facet joint. Once inserted within the facet, the nitinol hooks  476  may be activated via temperature, force, or other activation means causing them to assume their original (pre-flattened) shape and hook into the opposing facet surfaces. As the hooks  476  engage the cortical bone of the facet surfaces, they distract the joint. This separation results in increased foraminal area and reduced nerve root compression. 
       FIGS.  66 A-C  show yet another embodiment of an implant  480 . In this embodiment, a hollow screw sleeve  482  may be placed within the facet joint. A wedge  484  may then be placed within the hollow screw sleeve  482  causing it to expand and distract the joint. Additionally, the screw sleeve  482  may include sharp barbs  486  having a refracted position and a ejected position. As the wedge  484  is inserted, the wedge  484  displaces the sharp barbs  486  causing them to be ejected through the screw sleeve  482  and engage the facet surfaces. These barbs  486  may provide acute fixation of the implant  480  to the joint and prevent migration of the implant  480 . The distraction and separation of the joint result in increased foraminal area and reduced nerve root compression. 
       FIGS.  67 A-C  show yet another embodiment of an implant  488 . In this embodiment, a panel anchor implant  488  may be placed within the facet joint. The implant  488  may include a bolt  490  and collapsible nut  492  that is rotationally free from the bolt  490  near the head of the bolt  490  and threadably engaged with the bolt  490  near the end opposite the head. As such, when the bolt  490  is advanced, the distal end of the nut  492  is squeezed toward the proximal end of the nut  492  and the nut  492  may collapse with an accordion effect. As shown, the compression of the nut  492  results in a taller structure that applies a distraction force to the opposing facet surfaces. This distraction leads to increased foraminal area and reduced nerve root compression. 
     In similar fashion, the embodiment shown in  FIGS.  68 A-C  may collapse causing distraction of the joint. In lieu of the nut  492  shown in  FIGS.  67 A-C , this embodiment, shows a flat plate  494  that collapses into an accordion shape. 
       FIGS.  69 A-C  show yet another embodiment of an implant  496 . In this embodiment, an implant  496  is placed within the facet joint. The implant could have a number of shapes and sizes but, in this embodiment, has a tension wire  498  that surrounds the implant  496  and is pulled taught during implantation. Once the implant  496  is properly positioned, the wire&#39;s tension is released. The release of this tension causes the wire  498  to return to a preset expanded shape and height that causes the implant  496  to expand. The expansion of the implant  496  as the wire returns to its preset, and larger profile, shape causes separation of the facet joint. This distraction results in increased foraminal area and reduced nerve root compression. 
     Similarly, as shown in  FIGS.  70 A-C , an implant  500  with an outer housing  502  and an internal spring  504  may be positioned in the facet joint with the wire spring  504  in a tensioned or elongated position. Once properly positioned, the tension on the spring  504  may be released thus collapsing the spring  504  and expanding the associated housing  502  of the implant  500 . 
       FIGS.  71 A-C  show yet another embodiment of an implant  506 . In this embodiment screw type implant  506  may be provided and may also include an arm type locking mechanism  508 . The locking mechanism  508  may extend from all sides of the head of the screw as shown and may be biased in a distal direction. As the screw advances, the locking mechanism  508  may anchor in the lateral mass of a vertebra. The biased position of the arm  508  pressing against the lateral mass may provide a force biasing the implant  506  against the advancing direction. However, this may cause constant friction between any newly cut threads in the surfaces of the facet joint thereby preventing unscrewing or back out of the implant. In addition, teeth  509  may be included on the arms  508  and may bite into the lateral mass further preventing backing out of the implant. 
       FIGS.  72 A-C  show yet another embodiment of an implant  510 . In this embodiment, two wedge shape opposing structures  512  are shown separated by a sloping plane  514 . The structures  512  may have a predetermined relative position, or a series of predetermined relative positions, where a bolt or screw  516  may be advanced at an angle as shown through one of the structures  512  and into a predrilled hole of the other 512 to maintain their relative position. Alternatively, the relative positions may not predetermined and a self-drilling screw  516  may be used. In either case, the implant  510  may be positioned in the facet joint in minimal profile position and then the two structures  512  may be slid relative to each other along the sloping plane  514  to expand the implant  510  and thus the facet joint. Once the desired position is achieved, the bolt, pin, screw, or other fastener  516  may be inserted to maintain the relative position of the structures  512 . 
       FIGS.  73 A-C  show yet another embodiment of an implant  518 . In this embodiment, an implant  518  is configured to be inserted in a collapsed state. In its non collapsed state, it has a vertical cylindrical profile with side cutouts  520 . When the implant is compressed, the side cutouts  520  allow the wall panels  522  to bend out as the height of the cylindrical implant  518  is reduced. These wall panels  522  create an anchor shape that can engage bone structures. This implant  518  may be placed within the facet join in its flattened, compressed profile. Once it is positioned correctly, a distraction energy may be applied to the implant  518  to cause it to expand or decompress. This decompression causes the implant  518  to attempt to return to its vertical cylindrical shape. The implant  518  may be made from a resilient elastic material such as nitinol, stainless steel, or other known materials. As the implant  518  becomes more cylindrical, it pushes against the opposing facet surfaces. This force causes distraction of the facet joint and results in increase foraminal area and reduced nerve root compression. 
     Similarly, as shown in  FIGS.  74 A-C , the implant  518  may be positioned on its side and the distraction energy may cause the implant  518  to collapse from its cylindrical shape and expand laterally to distract the facet joint. 
       FIGS.  75 A-B  show yet another embodiment of an implant  524 . In this embodiment, a delivery tool  526  is inserted within the facet joint. The distal tip  528  of the delivery tool  526  is shaped to distract the joint. Once the tool  526  is inserted into the facet joint and the desired amount of distraction is achieved, the distal tip  528  (part that is in the facet joint) may be detached from the delivery tool  526 . In one configuration of this embodiment, the detachable tip  528  would have teeth, cleats, spikes, or keels  530  to prevent it from migrating within the joint once it is detached. In another configuration of this embodiment, the implant  524  may be anchored in the facet joint by inserting a screw  532  through the superior facet, the implant, and the inferior facet. In both configurations, the detachable tip  526  (implant) may provide permanent distraction of the joint resulting in increased foraminal area and reduced nerve root compression. 
       FIGS.  76 A-C  show yet another embodiment of an implant  534 . In this embodiment, the implant  534  may include a housing  536  with a central gear  538  turnable by an allen type head  540  or other known attachment for turning, such as any known screwdriver heads. Adjacent the central gear  538  on each side, the implant  534  may include two plates  542  slidable in the housing  536  in a direction tangential to the gear surface. The plates  542  may include teeth  544  engaging the central gear  538  such that when the gear  538  turns, the plates  542  slide tangentially to the gear  538  and extend beyond an outer surface of the housing  536 . As such, the implant  534  may be positioned in a facet joint as shown in  FIG.  76 A . Once positioned, the gear  538  may be turned thus extending the plates  542  in opposite directions and distracting the facet joint. 
       FIGS.  77 A-C  show another embodiment of an implant  546 . In this embodiment a triangular shaped implant  546  in the form of a bent plate  548  may be wedged into the facet causing distraction and separation of the joint. On one side of the triangular distraction structure  548  is a bracket  550  with a screw  552 . The screw  552  may be inserted into the lateral mass to provide anchoring of the facet distraction implant  546 . The other side of the triangular distraction structure  548  may include teeth or other features  554  for biting into the associated lateral mass. The implant  546  would provide permanent distraction of the joint resulting in increase foraminal area and reduced nerve root compression. 
       FIGS.  78 A-C  show another embodiment of an implant  556 . In this embodiment, the implant  556  may have a tapered shape that is taller at the posterior aspect relative to the anterior aspect. The implant could be tapped in, malleted in, screwed in with threads, or pushed in with hand pressure. Once the implant  556  is positioned correctly, the head  558  of the implant  556  (posterior aspect) may be configured to have sharp teeth, spikes, or cleats that can be pushed into the cortical bone of the superior and inferior lateral masses of a motion segment. These flaps  558  could be hinged on the posterior aspect of the implant  556  to allow the flaps  558  to be pushed anterior enough to match the irregular contours of the lateral mass. The implant  556  would provide permanent distraction of the joint resulting in increase foraminal area and reduced nerve root compression. 
       FIGS.  79 A-C  show another embodiment of an implant  560 . In this embodiment, the implant  560  includes a single rotatable cone  562  with a shoulder shaped ledge  564  defining a cam surface  566 , the distance between the ledge and the bottom of the implant defining a shoulder height. The shoulder height may vary gradually from low to high and back to low along the circumferential perimeter of the cone  562 . In use, the implant  560  may be initially positioned such that the shoulder portion with the low ledge height enters the facet joint. Once in position, the implant  560  may be rotated to cause the higher ledge height to enter the joint thereby distracting the posterior portion of the joint by causing the superior articular face to ride upward along the cam surface  566 . The implant  560  may then be secured with a screw  568  extending along the longitudinal axis of the implant. 
       FIGS.  80 A-D  show yet another embodiment of an implant  570 . In this embodiment, an implant  570  may include a housing  572  with penetrations  574  adapted for ejection of retracted spikes  576 . Within the housing  572 , a wire  578  may be routed between the spikes  576  as shown in  FIG.  80 D . The implant  570  may be inserted into the facet joint while the wire  578  is relaxed and the spikes  576  are contained within the folds/curves in the collapsed wire  578 . Once the implant  570  is positioned correctly, the wire  578  may be pulled taught causing the spikes  576  to displace outwardly, extending out of the housing  572  and engaging the opposing facet surfaces with a force. This force may create distraction and separation of the joint, while the pointed tips of the spikes  576  would penetrate the surface of the facet joint and provide acute fixation preventing migration of the implant  570 . The implant  570  would provide permanent distraction of the joint resulting in increase foraminal area and reduced nerve root compression. 
       FIGS.  81 A-C  show yet another embodiment of an implant  580 . In this embodiment, an implant  580  may include a housing  582  with a cavity  584  and penetrations  586  on lateral surfaces extending from the cavity  584  through the wall of the housing  582 , the penetrations  586  adapted for ejection of retracted spikes  588 . Within the housing  582 , a threaded piston  590  may be positioned at a distal end and may be adapted for displacement through the cavity  584  in the proximal direction. The piston  590  may have a torpedo shaped distal end  592  and may engage the a beveled inner surface  594  of the retracted spikes  588 . The implant  580  may be positioned within a facet joint and when properly positioned, the piston  590  may be advanced via a turning tool, the torpedo shaped distal end  592  of the piston  590  thus engaging the beveled end  594  of the spikes  588  and advancing them laterally relative to the implant  580  out of the housing  582  with a force and into the face of the facets. This force may create distraction and separation of the joint, while the pointed tips of the spikes  588  would penetrate the surface of the facet joint and provide acute fixation preventing migration of the implant  580 . 
       FIGS.  82 A-F  show yet another embodiment of an implant  596 . In this embodiment, the implant  596  may include two parallel equal length side bars  598  with pivoting struts  600  positioned on a pin  602  between the bars  598  at each end. The pivoting struts  600  may include textured surfaces  604  on each end and the struts  600  may be pinned to the side bars  598  through one end. As shown in  FIG.  82 F , the struts  600  may have length so as to allow them to be pivoted to lie parallel to one another in the plane of the side bars  598 . In this position, the implant  596  may be positioned in the facet joint as shown in  FIG.  82 A  or anterior to the facet joint as shown in  FIG.  82 D . Once properly positioned, the struts  600  of the implant  596  may be rotated so as to be approximately perpendicular to parallel side bars  598  thus separating an inferior vertebra from a inferior vertebra. It is noted that the generally stout shape of the struts  600  with relatively broad textured ends  604  may facilitate stability preventing the implant  596  from racking back to the parallel condition. 
     Another variation of this embodiment is shown in  FIGS.  83 A-B , where a series of varying height struts  600  are positioned along a shaft. The entire implant may be placed within a facet joint on its side and then a single ninety degree turn may position the implant and distract the joint. 
       FIGS.  84 A-B  show yet another embodiment of an implant  606 . In this embodiment, two rotatable cams  608  may be positioned in a facet joint. It is noted that the cams may have a relatively low profile and the proportions in the FIGS. may be exaggerated for purposes of showing the concept. Once placed in the joint, a distraction/rotation energy may be applied to the cams causing them to rotate open to reveal two circular halves of the cam implant. As one half of the implant rotates superiorly, it may push the superior vertebra upward creating an increase in foraminal area and nerve root decompression. 
     In another embodiment, a kit is provided. As shown in  FIGS.  85  and  86   , the kit may include a delivery device  610 , a chisel  612 , several internal and external decorticators  614 ,  616 ,  618 , and a driver assembly  620 . As shown in  FIGS.  87  and  88   , the chisel head  622  and shaft  624  may be provided in two pieces that may be combined with a press fit. As shown in  FIG.  89   , the delivery device  610  may be provided in two pieces combinable with a press fit, the first piece being a tubular shaft and fork piece  626  and the second piece being a receiving assembly piece  628 . As show in  FIGS.  90 - 93   , the driver assembly  620  may be provided in several pieces including the internal actuator and the implant shaft/arms/handle portion.  FIG.  90    shows the shaft/arms/handle portion comprising two pieces, the first piece being a shaft with arms  630  and the second piece being the handle  632 .  FIGS.  91  and  92    show the internal actuator including a tip  634 , a shaft portion  636 , an adapter  638 , a pin  640 , and a distractor knob  642 . In addition to the elements shown, one or several implants may be provided as well as an injector as previously described. Several traditional instruments for use in accessing the surgical site and closing the surgical site may also be provided. 
     Referring now to  FIGS.  94 - 116   , another embodiment of a tool  800  is shown.  FIGS.  94 - 98    show a chisel  808 , a delivery device  804 , a decorticator  806 , a driver assembly  842 , an internal actuator  852 , and an injector  902 . 
     As shown in  FIG.  95   , the delivery device  804  may include a receiving assembly  810  at a proximal end, anchoring forks  812  at a distal end, and a generally tubular shaft  814  defining a longitudinal axis and extending between the receiving assembly  810  and the anchoring forks  812 . The tubular shaft  814  may have an annular shaped cross-section with an inner radius and an outer radius, where the difference between the two radii defines a thickness of the tubular shaft  814 . Some of the features of the delivery device  804  will now be described and additional features of the delivery device  804  may include those features shown and described with respect to delivery device  104 . For example, the delivery device  804  may include two anchoring forks  812 . 
     The receiving assembly  810  of the delivery device  804  may have a generally rectangular outer surface defining a generally solid volume with a bore  811  there through. The bore  811  may be positioned proximal to and in alignment with the tubular shaft  814  and may have an inner radius matching that of the tubular shaft  814  allowing for a smooth transition of devices from the receiving assembly into the tubular shaft. The receiving assembly  810  may include a seating cavity  813  at its proximal end for receiving and seating of other devices such as the driver assembly  842  or the injector  902 . The seating cavity  813  may be defined by an outer shell  815  that is substantially flush with the outer surface of the receiving assembly  810 . The shell  815  may include protrusions or recesses  817  on its inner surface, the protrusions or recesses  817  corresponding to protrusions or recesses on other devices. As such, these protrusions or recesses  817  may provide for a detent relationship between the delivery device  804  and other devices. The rectangular outer surface of the receiving assembly  810  may have a long side and a short side. The long side may be oriented parallel to a line connecting the forks  812  in turn aligning the seating cavity  813  with the forks  812 . As such, devices used with the delivery device  804  may be properly aligned relative to the forks  812  by positioning and seating them in the seating cavity  813 . Additionally shown on the outer surface of the receiving assembly  810  is a decorticator release button  819 . As shown, the button  819  may include slots on either side creating a cantilevered tab condition for the button  819 . As such, the button  819  may deflect about its proximal end when depressed. The button  819  may also include recesses or bumps on its surface for gripping. The button  819  may extend beyond the distal end of the receiving assembly  810  and may include an upwardly extending ridge  821 . The ridge  821  may be shaped and adapted to engage the decorticator  806  as described in greater detail below. There may be one button  819 , or two buttons  819 , one on each face of the receiving assembly  810 . Any number of buttons  819  may be included, for example in the case of a varying shaped receiving assembly,  810 . 
     Referring to  FIG.  94   , the chisel  808  may have a generally cylindrical cross-section forming a shaft  828 . The shaft  828  may have a radius substantially equal to the inner radius of the tubular shaft  814  portion of the delivery device  804  allowing for slidable insertion of the chisel  808  within the delivery device  804 . Alternatively, the radius of the shaft  828  may be smaller than the inner radius of the tubular shaft  814  providing for more play and adjustability of the chisel  808  and delivery device  804  relative to one another. The chisel  808  may include a single or doubly chamfered tip  830  at a distal end or may have a coped distal end. The chisel  808  may include a head or, in contrast to the chisel  108  described with respect to  FIG.  1   , the chisel  808  may not include a head as shown in  FIG.  94   . The chisel  808  may have an overall length slightly larger than the delivery device  804  so as to allow the chisel to be manipulated by its proximal end when sleeved within the delivery device  804 . Additional features of the chisel  808  may include those features shown and described with respect to chisel  108 . For example, similar to the chisel shown and described with respect to  FIG.  1 A , the chisel  808  may also include a longitudinally extending lumen  131 . A more detailed view of the chisel  808  and its chamfered tip  830  may be seen in  FIG.  94 A . As shown, the chisel  808  may include a circumferential bevel at its proximal end opposite the chamfered tip  830 . 
     In comparison to the use described with respect to  FIG.  5    above, it is noted that the chisel  808  may allow the option of inserting the chisel  808  prior to the delivery device  804  and sleeving the delivery device  804  over the chisel  808 . This is in contrast to the chisel  108 , with the head  132 , where the head  132  prevents the delivery device  104  from being sleeved over the chisel  108 . As such, the facet joint may be distracted by the chisel  808  initially allowing for smoother insertion of the delivery device  804 . Upon placement and proper positioning of the delivery device  804 , the chisel  808  may then be removed. Those of skill in the art will understand and appreciate that a chisel with a removable head may also be provided and may allow for either order of insertion of the delivery device  804  and chisel  808  and the removable head, once replaced, may then be used to more readily manipulate and properly position the chisel  808 . 
     In some embodiments, the forks  812  at the distal end of the delivery device  804  may have a bull nose tip as shown in  FIG.  95 A . This is in contrast to the relatively sharp tip shown in  FIGS.  2 - 4    with respect to forks  112 . The use of a chisel  808  without a handle, which may allow for insertion of the chisel  808  prior to the delivery device  804 , may, in turn, allow for this bull nose tip because the facet joint may be distracted prior to insertion of the delivery device  804 . 
     Referring again to  FIG.  95   , the decorticator  806  may have a tubular shaft portion  834 , an abrasive distal end  836 , and a handle  838  at a proximal end. The tubular shaft  834  may have an inner radius substantially equal to the outer radius of the tubular shaft  814  of the delivery device  804  and may allow for sliding movement of the decorticator  806  along the length of the delivery device  804  and rotationally around the delivery device  804 . In some embodiments, the inner radius of the tubular shaft  834  may be slightly or substantially larger than the outer radius of the tubular shaft  814  of the delivery device allowing for more freedom of movement of the decorticator  806 . The abrasive distal end  836  may include serrated teeth as shown, or may include a more flat annular surface with a gritty surface. The handle  838  may include a generally cylindrically shaped knob with a gripping surface along its peripheral edge. The handle  838  may also include a cavity on its proximal face for receiving a distal end of the decorticator release button  819 . The cavity may thus create an inner cylindrical surface opposite the gripping surface of the handle  838 . The inner cylindrical surface may be beveled or may include a groove for receiving the tip of the ridge  821  extending upwardly from the release button  819 . As such, where the release button  819  is in its natural state, the ridge  821  may project into the groove or opposed to the beveled surface of the handle  838  preventing the decorticator from being advanced distally. Where the release button  819  is depressed, the ridge may be removed from the groove or beveled surface allowing the decorticator to advance freely. Additional features of the decorticator  806  may include those features shown and described with respect to decorticator  106 . For example, the decorticator  806  may alternatively be separate from the delivery device  804  and may be slidably inserted within the delivery device  804  similar to that shown and described with respect to  FIG.  4    or  FIGS.  6 A- 6 C . 
     Referring now to  FIGS.  99 - 101   , the delivery device  804  and a driver assembly  842  are shown. As shown in  FIG.  99   , the driver assembly  842  includes a handle  844 , an implant shaft  846 , and implant holding arms  848 . The driver assembly  842  shown is holding an implant  154 . The handle  844  of the driver assembly  842  may have an outer surface defining a generally rectangular volume with a bore  843  there through. The bore  843  may have an inner diameter substantially equal to the inner diameter of the implant shaft  846  allowing for a smooth transition of devices passing through the driver assembly  842 . The handle  844  may have a necked down portion  845  at its distal end. The necked down portion  845  may have protrusions or recesses  847  on its outer surface corresponding to respective protrusions or recesses  817  on the inner surface of the shell  815  of the receiving assembly  810  on the delivery device  804 . As such, and as shown in  FIGS.  100  and  101   , the driver assembly  842  may be sleevably positioned within the delivery device  804  to deliver an implant  154 / 854  to the facet joint. When fully advanced as shown in  FIG.  101   , the handle  844  may be seated securely in the seating cavity  813  of the receiving assembly  810  and anchored with a detent relationship. Additional features of the driver assembly  842  may include those features shown and described with respect to driver assembly  142 . 
     A more detailed view of the implant holding arms  848  is shown in  FIG.  99 A . As shown, the implant holding arms  848  may include a chamfered tip. Additional features of the arms  848  may include features similar to those shown and described with respect to arms  148  in relation to  FIG.  11   . For example, the inside surface of the arms  848  may include a longitudinal ridge  862  extending the length of the arms  848 . The arms  848  may also include a bull nose engagement feature  858  extending transverse to the longitudinal axis of the implant shaft  846  along the inside face of the arm  848 . Where the arms  848  are engaged with and holding the implant  154 / 854 , the longitudinal ridges  862  of each arm  848  may be positioned between upper and lower planar members of the implant  154 / 854  and the bull nose engagement features  858  may be positioned in the U-shaped receiving feature slots on the lateral edges of the implant  154 / 854 . 
     In contrast to the driver assembly  142  described above, in the present embodiment shown in  FIGS.  102 - 105   , the internal actuator  852  may be a separate device from the driver assembly  842 . That is, while the internal actuator  852  may still function by passing longitudinally through the driver assembly  842 , the internal actuator  852  may be a separate device with its own handle  853 . The internal actuator  852  may include a longitudinal shaft  855  and an internal rod  857 . The longitudinal shaft  855  may be cylindrically shaped with an annular cross-section. The shaft  855  may have an outer diameter substantially the same as or smaller than the inner diameter of the implant shaft  846  of the driver assembly  842 . The shaft  855  may extend from the handle  853  proximally to a distal end. The internal rod  857  may be positioned within the shaft  855  and also may extend from the handle  853  to a distal end. The internal rod  857  may include an engagement feature  859  at its distal end for engaging and holding the implant distractor  850 . This engagement feature  859  may be any shape and provide for any engagement known in the art from a hex, allen, phillips, star, square, sleeve, or other connection capable of transmitting longitudinal and/or rotational forces from the internal rod  857  to the implant distractor  850 . As shown, in one embodiment, the engagement feature  859  includes a collet type device that is described in more detail with respect to  FIG.  109    below. As shown, the internal rod  857  may sleevably receive the implant distractor  850 . The internal rod  857  may be sleevably positioned within the longitudinal shaft  855 , such that when the longitudinal shaft  855  is in an advanced position over the end of the internal rod  857 , the longitudinal shaft  855  causes a clamping force of the collet to restrain the implant distractor  850  against being dislodged from the collet. Each of the shaft  855  and the internal rod  857  may engage the handle  853  at their respective proximal ends. The handle  853  may be used to retract the longitudinal shaft  855  along the length of the internal rod  857  thereby exposing the collet and reducing the clamping force. As such, when the longitudinal shaft  855  is in a retracted position, an implant distractor may be inserted into and/or removed from the collet. 
     As shown in  FIGS.  104  and  105   , the handle  853  may be a cylindrical/spherical handle or a T-type handle. Referring to  FIG.  104   , the cylindrical/spherical handle may include an outer cylindrical portion  861  capped at a proximal end by a first spherical portion  863 , the first outer cylindrical portion  861  being open at a distal end. The handle  853  may also include an inner cylindrical portion  865  capped at a distal end by a second spherical portion  867 , the inner cylindrical portion  865  being open at a proximal end. As shown, the proximal open end of the outer cylindrical portion  861  may be positioned opposing the distal open end of the inner cylindrical portion  865  and the inner cylindrical portion  865  may sleevably slide within the outer cylindrical portion  861 . The handle  853  may further include a collar  869  integral with the second spherical portion  867 , positioned concentrically to each of the outer and inner cylindrical portions  861 ,  865  and extending distally away from the second spherical portion  865 . Those of skill in the art will understand and appreciate that the collar  869  could also extend in a proximal direction. In either case, the shaft  855  of the internal actuator  852  may be connected to the distal end of the collar  869  and extend distally there from. The internal rod  857  of the internal actuator  852  passing proximally through the shaft may sleevably penetrate the collar  869  and the second spherical portion  867 , extend through the handle  853  to the inner/distal surface of the first spherical portion  863 , and be coupled thereto. In addition, the first and second spherical portions  863 ,  867  may have a biasing mechanism  871  positioned between them in the form of a spring, balloon, or other force inducing device. Those of skill in the art will understand and appreciate that the spherical portions  863 ,  867  could be flat, concave, or otherwise shaped and are not limited to spherical shaped caps. 
     In use, as understood by a review of  FIGS.  103  and  104   , a user may insert the internal actuator  852  through the driver assembly  842 , which is positioned and seated in the delivery device  804 . The internal actuator  852  may be used to advance and position the implant distractor  850  for advancement into the implant. Once properly positioned, the internal actuator  852  may be rotated via the handle  853  to advance the implant distractor  850 . In the cases of other implant distractors, the handle  853  may be otherwise manipulated to advance the implant distractor. Once the implant distractor is advanced and the implant is distracted, a user may compress the first and second spherical portions  863 ,  867  toward one another against the force of the biasing mechanism  871  (e.g. by squeezing the handle with their hand). The inner cylindrical portion  865  of the handle  853  may retract relative to the outer cylindrical portion  861  causing the longitudinal shaft  855  also to retract relative to the to the outer cylindrical portion  861 . This retracting motion relative to the internal rod  857  may cause the distal end of the longitudinal shaft  855  to be retracted and expose the collet on the distal end of the internal rod  857 . As such, the clamping force of the collet on the implant distractor  850  may be reduced allowing for removal of the internal actuator  852 , while leaving the implant distractor  850  behine and in place in the implant. It is noted that the shaft portion  855  of the implant distractor  852  may include a keyway for engagement with the inner surface of the implant shaft  846  of the driver assembly  842 . As such, the shaft  855  of the internal actuator  852  may be prevented from rotating relative to the internal rod  857 . 
     Referring now to  FIG.  105   , the T-type handle may have a cylindrical, rectangular, square, or other transverse cross-section, with a longitudinal axis extending generally perpendicular to the longitudinal axis of the internal rod  857  and shaft  855  and forming a T-shape. The longitudinal cross-section of the handle  853 , as depicted in  FIG.  105   , may include a proximal portion  873  and a distal portion  875  connected at one end and separated by a gap  877 . The proximal portion  873  may be a relatively thick portion and the distal portion  875  may be relative thin. As such, the handle  853  may be squeezable and may provide a biasing force which works to maintain the gap  877  between the distal and proximal portions  873 ,  875 . The handle  853  may also include a generally cylindrical or conical collar  879  positioned near the middle of the handle  853  along its longitudinal length. The collar  879  may be positioned parallel to and concentrically with the internal rod  857 . The shaft portion  855  of the internal actuator  852  may extend distally from the distal end of the collar  879 . The internal rod  857  may sleevably penetrate the collar  879  and the distal portion  875  of the handle  853  and may further be coupled to the proximal portion  873  of the handle  853  in a cylindrical bore  881 . A stop may be provided to prevent the internal rod  857  from passing proximally through the proximal portion  873  of the handle  853 . This may be in the form of a cap on the proximal portion  873  of the handle  853  covering the bore  881 , or the bore  881  may not pass all the way through the proximal portion  873  of the handle  853 . Alternatively, the internal rod  857  may be secured within the bore. 
     In this embodiment, as understood by a review of  FIGS.  103  and  105   , the internal actuator  852  may be inserted through the driver assembly  842  and the implant distractor  850  may be advanced in the same or similar fashion as that described with respect to the internal actuator  852  of  FIG.  104   . When the internal actuator is ready for removal, a user may compress the proximal  873  and distal  875  portions of the handle  853  toward one another against the biasing force by squeezing the handle  853 . The distal portion  875  of the handle  853  may retract relative to the proximal portion  873  causing the longitudinal shaft  855  also to retract relative to the proximal portion  873 . This retracting motion of the longitudinal shaft  855  relative to the internal rod  857  may cause the distal end of the longitudinal shaft  855  to be retracted and expose the collet on the distal end of the internal rod  857 . As such, the clamping force of the collet on the implant distractor  850  may be reduced allowing for removal of the internal actuator  852 , while leaving the implant distractor  850  behind and in place in the implant. 
     Still another embodiment of a handle  853  is shown in  FIGS.  106 - 108   . In this embodiment, a gripping mass  883  with a knob  885  is shown. A knob  885  is positioned on the proximal end of the internal rod  857  via a bore  887 . The knob  885  may be affixed against relative rotation with the internal rod  857 . The gripping mass  883  may include a generally rectangular mass spaced from the knob  885  along the internal rod  857  and including a bore  889  for the internal rod  857  to pass there through. The bore  889  may sleevably receive the internal rod  857 . The gripping mass  883  and the internal rod  857  may form the shape of a T and the gripping mass  883  may be affixed to the proximal end of the longitudinal shaft  855 . The gripping mass  883  may be held apart from the knob  885  along the internal rod  857  by a biasing mechanism  891  in the form of a spring, balloon, or other known device. 
     The implant distractor  852  shown in  FIGS.  106  and  107    may be inserted through the driver assembly similar to that shown and described with respect to  FIG.  103    above. The implant distractor may be rotated or otherwise manipulated to advance the implant distractor  850 . Once the implant distractor is positioned, a user may grip the gripping mass  883  with their fingers and allow the knob  885  to settle into the palm of their hand. The user may then squeeze the knob  885  toward the gripping mass  883  depressing the biasing mechanism  891  between the two and retracting the longitudinal shaft  855  along the internal rod  857  and causing the distal end of the longitudinal shaft  855  to be retracted and expose the collet on the distal end of the internal rod  857 . As such, the clamping force of the collet on the implant distractor  850  may be reduced allowing for removal of the internal actuator  852 , while leaving the implant distractor  850  behind and in place in the implant. 
     As shown in more detail in  FIG.  108   , the engagement feature  859  at the distal end of the internal rod  857  may take the form of a collet  893  for holding the implant distractor  850 . The collet  893  may be affixed to the distal end of the internal rod  857  and may be adapted to hold the implant distractor  850 . Those of skill in the art will understand and appreciate that the collet  893  may be permanently affixed to the distal end of the internal rod  857  or may be interchangeably coupled thereto. Those of skill will further understand that several collet and chuck arrangements are known in the tool industry for receiving bits or other devices, which are within the scope of the invention. As shown, the collet  893  is extending slightly out of the distal end of the longitudinal shaft  855  and is thus in position to receive an implant distractor or is in position to allow removal of the internal actuator  852  after placement of the implant distractor  850 . 
     The collet  893 , positioned on the distal end of the internal rod  857  and shown in  FIG.  108   , may be seen more clearly in  FIG.  109   . In some embodiments as shown, the collet  893  may include a generally cylindrical body member  895  with four receiving fingers  897  equally spaced around a bore  899 . The body member  895  may be the internal rod  857  or may be a separate piece which is affixed to the end of the internal rod  857 . Each of the fingers  897  may extend distally from the body member  895  and be separated by slots  901 . The fingers  897  may extend laterally across approximately one quarter of a cylinder wall and may have constant thickness as they extend from the body  895 . Near the distal end of the fingers  897 , the outer surface of each finger  897  may be tapered up to define a thicker finger thickness and then tapered back down at the very distal end. As such, when the longitudinal shaft  855  is advanced over the collet  893 , the tapered outer surface causes the fingers  897  to deflect inward creating a clamping force on the implant distractor positioned within the collet. Those of skill in the art will understand and appreciate that the collet may include as few as two fingers  897  and may include any number of fingers. The bore  899  defined by the fingers  897  may extend into the cylindrical body  895  a specified distance. At the transition  903  between the body  895  and fingers  897 , which location is defined by the depth of the slots  901 , the transition  903  defines a neck where a wider body portion  895  necks down to the finger portion  897 . 
     Referring now to  FIG.  110   , a cross-section of the longitudinal shaft  855  is shown. As shown, the longitudinal shaft  855  may include an internal bore  905  at its distal end for receiving the internal rod  857  and the collet  893 . The internal bore  905  may be the same or similar to the bore extending the length of the longitudinal shaft  855 . The distal end of the bore  905  may include an outwardly beveled edge for riding along the beveled outer surface of the collet  893  when the longitudinal shaft is advanced and creates a clamping force on the collet.  893   
     Referring now to  FIGS.  111 - 113    an implant distractor  850  is shown. The implant distractor  850  may be a generally narrow element having a cylindrical body  907  which tapers to a point at a distal end. At a proximal end  864 , the implant distractor  850  may have a square cross-section and may include a circumferential groove  909  positioned just proximal to the distal end of the implant distractor  850 . This groove  909  may correspond to a protrusion or spring ball on the inner surface of the engagement feature  859  of the internal actuator  852  forming a detent connection between the engagement feature  859  and the implant distractor  850 . Alternatively or additionally, where a collet  893  is used the groove  909  may engage a feature inside the collet  893  so as to prevent the implant distractor  850  from inadvertently dislodging from the collet  893 . The square proximal end  864  may be isolated from the cylindrical body  907  by an annular stop ring  911 . The annular stop ring  911  may have an outer radius similar to the inner radius of the driver assembly  842 . This stop ring  911  may allow for sliding movement of the implant distractor  850  through the implant shaft  846  of the driver assembly  842 . The stop ring  911  may prevent over advancement of the implant distractor  850  by creating an abutting relationship between the distal face of the stop ring and the proximal edge of the implant. 
     As best shown in  FIGS.  112  and  113   , the implant distractor  850  may include a generally continuous coil-shaped thread feature  866 . The thread feature  866  may have an abrupt proximal end  913  just distal to the annular stop ring  911  and may continue to the distal end of the implant distractor  850 . The thread feature  866  may gradually terminate at the distal end of the implant distractor  850  by gradually minimizing its cross-sectional profile. This may occur over several turns or in some embodiments, this transition may occur within a 180 degree turn. In other embodiments, this transition occurs between a 90 degree and a 180 degree turn. While the thread feature  866  is generally continuous, as shown in  FIG.  112   , the thread feature  866  may be interrupted by at least one cross-cut  915  at one or more locations along the threaded feature  866 . In one embodiment, as shown in  FIG.  112   , a single cross-cut  915  may be positioned just proximal to the distal end. This cross-cut  915  may be positioned approximately 180 degrees out of phase from the abrupt proximal end  913  of the thread feature  866 . Both the cross-cut  915  and the abrupt proximal end  913  may provide for interlocking engagement of the implant distractor  850  with the implant  154 / 854  and thus prevent backing out of the implant distractor  850 . 
     Turning now to  FIGS.  114 - 116   , an injector  902  and delivery device  804  are shown. As shown in  FIG.  114   , the injector  902  may include a longitudinal delivery shaft  917 , a seating feature  919 , a gripping feature  921 , and a plunger  923  with a handle  925 . The longitudinal delivery shaft  917  may have any cross-section and may have a cross-sectional size adapted to fit within the delivery device  804 . The longitudinal shaft  917  may have an opening  927  on its distal end for directing bone paste toward the lateral mass portion of a facet joint. In another embodiment, the shaft  917  may include two opposing openings  927  or a series of openings  927  on its distal end. The openings  927  may be positioned to penetrate the wall of shaft  917 . The seating feature  919  may include a rectangular or other shaped block positioned around the shaft  917  and sized and shaped to engage the seating recess  813  in the receiving assembly  810  of the delivery device  804 . As shown, the seating feature  919  may include a necked down portion on its distal end which may be received by the shell portion  815  of the receiving assembly  810 . As with the driver assembly  842 , the seating feature  919  of the injector  902  may include protrusions or recesses  929  corresponding to protrusions or recesses  817  on the inner surface of the shell  815  allowing for a detent relationship for securing the injector  902  to the delivery device  804 . The seating feature  919  may have an orientation perpendicular to the orientation of the openings  927  at the distal end of the shaft  917  such that once in position, the openings  927  may direct bone paste or other material perpendicular to the facet joint surface along the spine and adjacent to the facet joint. The gripping feature  921  may be any shape and may be affixed to the proximal end of the shaft  917 . This feature  921  may include a gripping profile on its distal face for receiving  1 ,  2 , or any number of fingers on one or either side of the shaft  917 . The gripping feature  921  may allow the user to grasp the injector  902  and squeeze the plunger handle  925  toward the gripping feature  921  thus advancing the internal piston and ejecting the bone paste or other material. 
     As shown in  FIG.  116   , the injector  902  may be sleevably inserted into the delivery device  804  and advanced such that the distal end of the shaft  917  is positioned between the forks  812 . The seating feature  919  may be secured with the detents thus orienting the openings  927  in the shaft  917  perpendicular to the forks  812 . The plunger handle  925  may be squeezed relative to the gripping feature  921  and bone paste or other material may be injected toward the facet joint site. Additional features not mentioned may be included as shown and described with respect to the injector  202 . For example, the plunger  923  may include a seal. 
     Turning now to  FIGS.  117 - 120   , another embodiment of an implant  854  is shown. The implant  854  may include upper  868  and lower  870  members. The members  868 ,  870  may be generally planar and may also be generally rectangular. Each of the upper  868  and lower  870  members may include a proximal edge  872 , a distal edge  874 , and a pair of parallel lateral edges  876  extending longitudinally between the distal edges  874  and the proximal edges  872 . In the present embodiment, as shown in  FIGS.  117 - 120   , the distal edges  874  of the members  868 ,  870  may each include interlocking scissor features  931 . As shown, a portion of the member near the distal edge  874  of each member may be radiused and bend in the direction of the opposing member. As shown in  FIGS.  118  and  119   , an interlocking slot  933  may be provided extending laterally halfway across the member just proximal to the distal edge  874  and within the radiused bend portion of the member. In one embodiment, the width of the slot  933  may be generally similar in width to the distance from the distal edge  874  to the slot  933 . The slot  933  in the upper member  868  and lower member  870  may be positioned on the same side such that when one of the members is inverted, the slots may engage one another as best shown in  FIG.  120   . The upper and lower members  868 ,  870  may be welded together along an upper seam  935 , lower seam  937 , and/or a front seam  939 . Once interlocked, the planar members  868 ,  870  may be biased by the connection at their distal edges  874  to be generally parallel to each other, the inner faces  878  of the planar members  868 ,  870  facing each other in an opposed fashion and abutting or nearly abutting each other. It is noted that, while the interlocking slot  933  is shown extending anatomically laterally from the anatomical medial side of the upper member  868  and extending anatomically medially from the anatomical lateral side of the lower member  870 , the orientation of this slot may be reversed. This reversed orientation may provide resistance to shearing of the upper  868  and lower  870  members relative to one another upon receiving the implant distractor. That is, as the implant distractor is advanced into the implant  854 , it may be rotating in a clockwise fashion. When engaging the implant  854 , this rotation may have a tendency to cause the upper member  868  to shift laterally and to cause the lower member to shift medially. The reversed orientation may resist this shifting. 
     Additional features of the implant  854  may include those features shown and described with respect to implant  154 . For example, a guide feature  884  may be included as shown. As an additional example, threaded slots  888  may also be included in each planar member  868 ,  870  for receiving the coil-shaped thread feature  866  on the implant distractor  850 . In the present embodiment, one of the threaded slots  888  on one of the members  868 ,  870  may be a truncated threaded slot  941  for engaging the cross-cut thread  915  or the abrupt proximal end  913  of the coil-shaped thread feature  866  and preventing unscrewing or backing out of the implant distractor  850  once advanced and positioned. As shown in  FIGS.  118  and  119   , each member  868 ,  870  may have one truncated threaded slot  941  for engaging either a cross-cut thread  915  or the abrupt proximal end  913  of the thread feature  866 . As such, the implant distractor  850  may be held in place and prevented from backing out by both the upper and lower member  868 ,  870 . 
     Those of skill in the art will understand and appreciate that the implant embodiments depicted herein may be made of several types of biocompatible materials including stainless steel, titanium, ceramics, nitinol, polymers, and other materials known in the art. 
     Referring now to  FIGS.  121 - 128   , another embodiment of a tool  1000  is shown.  FIG.  121    shows a chisel  1008 , a delivery device  1004 , a decorticator  1006 , a driver assembly  1042 , an internal actuator  1052 , an internal rod  1057  for the internal actuator  1052 , an injector  1102 , and a gripping tool  1001 . 
     Referring to  FIG.  122   , the chisel  1008  may have a generally cylindrical cross-section forming a shaft  1028 . The shaft  1028  may have a radius substantially equal to the inner radius of the tubular shaft portion  1014  of the delivery device  1004  (shown in  FIG.  123   ) allowing for slidable insertion of the chisel  1008  within the delivery device  1004 . Alternatively, the radius of the shaft  1028  may be smaller than the inner radius of the tubular shaft  1014  providing for more play and adjustability of the chisel  1008  and delivery device  1004  relative to one another. In some embodiments the shaft  1028  may have a radius ranging from approximately 1 mm to approximately 8 mm. In other embodiments, the shaft  1028  may have a radius of approximately 4 mm. The chisel  1008  may include a single or doubly chamfered tip  1030  at a distal end or may have a coped distal end or a combination of coping and chamfering. The tip  1030  may include a roughened surface on one or more sides to aid in anchoring or docking the chisel in the facet joint. Additionally, this roughened surface may allow for roughening or decorticating the inner surfaces of the facet joint. The tip  1030  may have a length  1037  adapted to extend substantially across the facet joint. As such, the length  1037  may be any length corresponding to the distance across a given facet joint. In one embodiment, the length  1037  may fall within a range from approximately 5 mm to approximately 35 mm long. In another embodiment, the length may fall within a range from approximately 10 mm to approximately 30 mm. In yet another embodiment, the length may fall within a range from approximately 14 mm to approximately 29 mm. 
     The chisel  1008  may include a head or, in contrast to the chisel  108  described with respect to  FIG.  1   , the chisel  1008  may not include a head as shown in  FIG.  122   . The chisel  1008  may have an overall length slightly larger than the delivery device  1004  so as to allow the chisel  1008  to be manipulated by its proximal end when sleeved within the delivery device  1004 . The chisel  1008  may have a coped proximal end  1033  as shown. The cope  1033  may occur on one or more sides of the chisel  1008  and may allow for easier grasping of the chisel  1008  with other tools. For example, a slap hammer may be used to grasp the chisel  1008  and hammer back on the chisel  1008  during removal. Additionally, a hemostat may be used to grasp, manipulate, or otherwise distance the surgeon&#39;s hand and/or body from the proximal end of the chisel  1008  to facilitate taking of x-rays. Further shown in  FIG.  122    is a horizontal bore  1035  for receiving a shaft portion of the gripping tool  1001 . As such, the gripping tool  1001 , may be inserted into the horizontal bore  1035  in the proximal end of the chisel  1008  forming a T-shaped grip that may be used to manipulate the chisel  1008  and/or remove the chisel  1008 . 
     Additional features of the chisel  1008  may include features of the other chisels shown and described herein. For example, similar to the chisel shown and described with respect to  FIG.  1 A , the chisel  1008  may also include a longitudinally extending lumen. In this embodiment, the chisel  1008  may allow for insertion of a scope or flushing fluids as discussed above. Also, the chisel  1008  may allow for diagnostic processes. That is, the chisel  1008  may be positioned in a facet joint and a diagnostic balloon catheter may be inserted through the lumen of the chisel  1008  to distract the joint. Feedback from a consciously sedated patient may allow a provider to obtain information relating to symptom relief. As such, one or more joints may be reviewed diagnostically and thus may allow for treatment of one or several problematic joints with confidence that the proper joints are being treated. An exemplary diagnostic balloon catheter and method suitable for this application is described in U.S. patent application Ser. No. 12/110,548, entitled Cervical Distraction Method, filed on Apr. 28, 2008, the contents of which are hereby incorporated by reference herein. 
     In comparison to the use described with respect to  FIG.  5    above, it is noted that the chisel  1008  may allow the option of inserting the chisel  1008  prior to the delivery device  1004  and sleeving the delivery device  1004  over the chisel  1008 . This is in contrast to the chisel  108 , with the head  132 , where the head  132  may prevent the delivery device  104  from being sleeved over the chisel  108 . As such, the facet joint may be distracted by the chisel  1008  by inserting the chisel  1008  and tapping, hammering, or otherwise advancing the chisel  1008  into the facet joint. Once in place, the delivery device  1004  may be inserted. Upon placement and proper positioning of the delivery device  1004 , the chisel  1008  may then be removed. In another embodiment, a chisel with a removable head may also be provided and may allow for either order of insertion of the delivery device  1004  and chisel  1008 . In the case of inserting the chisel  1008  first, the removable head may initially be removed from the chisel  1008 . Once replaced, the removable head may then be used to more readily manipulate and properly position the chisel  1008 . 
     In some embodiments, the forks  1012  at the distal end of the delivery device  1004  may have a bull nose tip as shown in  FIG.  123   . This is in contrast to the relatively sharp tip shown in  FIGS.  2 - 4   . The use of a chisel  1008  without a handle, which may allow for insertion of the chisel  1008  prior to the delivery device  1004 , may, in turn, allow for this bull nose tip because the facet joint may be distracted prior to insertion of the delivery device  1004 . 
     In still further embodiments, the chisel  1008  may be radiolucent. That is, the chisel may be made of plastic or other material not reflected by an x-ray. This may allow for lateral fluoroscopy to more readily show the position of a chisel, delivery device, or other device in a contra lateral facet joint without obstructing the view. 
     As shown in  FIG.  123   , the delivery device  1004  may include a receiving assembly  1010  at a proximal end, anchoring forks  1012  at a distal end, and a generally tubular shaft  1014  defining a longitudinal axis and extending between the receiving assembly  1010  and the anchoring forks  1012 . The tubular shaft  1014  may have an annularly shaped cross-section with an inner radius and an outer radius, where the difference between the two radii defines a thickness of the tubular shaft  1014 . The delivery device may and all of the associated elements may be any size and may be adapted for the particular anatomy being addressed. In some embodiments, the outer radius of the tubular shaft  1014  may range from approximately 2 mm to approximately 8 mm. In some embodiments, the tubular shaft  1014  may have an outer radius of approximately 5 mm. 
     Some of the features of the delivery device  1004  will now be described and additional features of the delivery device  1004  may include features of other delivery devices shown and described herein, such as, for example, the anchoring forks  1012 . 
     The receiving assembly  1010  of the delivery device  1004 , shown in  FIGS.  123  and  123 A , may have a generally smooth contoured outer surface that transitions from a generally rectangular cross-section at a proximal end to a narrower and generally circular cross-section at a distal end, the receiving assembly defining a volume with a bore  1011  extending there through. The bore  1011  may be positioned proximal to and in alignment with the tubular shaft  1014  and may have an inner radius matching that of the tubular shaft  1014  allowing for a smooth transition of devices from the receiving assembly  1010  into the tubular shaft  1014 . As best shown in  FIG.  123 A , the tubular shaft  1014  may engage the receiving assembly  1010  with a dove tail connection  1017  around the periphery of the proximal end of the tubular shaft  1014 . Also shown in  FIG.  123 A  is a tapered entrance  1019  to the bore  1011  at its proximal end to facilitate ease of entry of other devices. The receiving assembly  1010  may include one or more seating cavities  1013  opening in a proximal direction for receiving and seating of other devices such as the driver assembly  1042  or the injector  1102 . These seating cavities  1013  may be defined by an outer shell  1015  that is substantially flush with the outer surface of the receiving assembly  1010 . The seating cavities  1013  may be positioned radially adjacent to the bore  1011 . In the present embodiment, two seating cavities are shown adjacent to the bore  1011  and on opposite sides of the bore  1011 . While not shown, the shell  1015  may include protrusions or recesses on its inner surface, the protrusions or recesses corresponding to protrusions or recesses on other devices. As such, these protrusions or recesses may provide for a detent relationship between the delivery device  1004  and other devices. Alternatively or in addition to the protrusions or recesses, the seating cavities  1013  may have an inner surface that tapers such that the cross-section of the cavity  1013  also tapers from a relatively broad cross-section at its proximal end to a relatively narrow cross-section at its distal end. As such, these seating cavities  1013  may provide for a friction fit between the receiving assembly  1010  and another device, where the other device may have a male portion with a shape corresponding to the shape of the seating cavity  1013 . The cross-sectional shape of the cavities  1013  may include a relatively trapezoidal shape with a concave base as shown, the base bordering along the perimeter of the bore  1011 . Any cross-sectional shape including square, rectangular, triangular, circular, or a more undefined random shape may be used. 
     The generally rectangular cross-section of the proximal portion of the receiving assembly  1010  may have a long side and a short side. The long side may be oriented parallel to a line connecting the forks  1012  in turn aligning the seating cavities  1013  with the forks  1012 . As such, devices used with the delivery device  1004  may be properly aligned relative to the forks  1012  by positioning and seating them in the seating cavities  1013 . 
     Just distal to the receiving assembly  1010 , a circumferential groove  1021  is shown on the tubular shaft  1014 . The groove  1021  may be adapted to aid in securing the decorticator (not shown), further described below. Alternatively, the groove  1021  may be adapted for gripping by a hemostat or other tool. For example, a hemostat may be used to hold the delivery device  1004  where the delivery device  1004  is being held in position for an x-ray and the practitioner or other user may be attempting to distance their hand from the x-ray field. 
     Also shown in  FIG.  123    are the forks  1012 . These forks  1012  may be adapted to anchor the delivery device  1004  in the facet joint. As such, similar to the chisel  1008 , the forks  1012  may include a roughened or toothed surface. Additionally, the distal ends of the forks  1012  may be beveled to aid in advancing the tool through tissues and avoid snags. Moreover, the length  1023  of the forks  1012  may be adapted to extend substantially across the facet joint. As such, in one embodiment, the length  1023  of the forks  1012  may range from approximately 5 mm to approximately 35 mm. In another embodiment, the length  1023  may range from approximately 10 mm to approximately 30 mm. In still another embodiment, the length  1023  may range from approximately 14 mm to approximately 29 mm. 
     Referring now to  FIG.  124   , the decorticator  1006  may have a tubular shaft portion  1034 , an abrasive distal end  1036 , and a handle  1038  at a proximal end. The tubular shaft  1034  may have an inner radius substantially equal to the outer radius of the tubular shaft  1014  of the delivery device  1004  and may allow for sliding movement of the decorticator  1006  along the length of the delivery device  1004  and rotationally around the delivery device  1004 . In some embodiments, the inner radius of the tubular shaft  1034  may be slightly or substantially larger than the outer radius of the tubular shaft  1014  of the delivery device  1004  allowing for more freedom of movement of the decorticator  1006 . In some embodiments, the outer radius of the decorticator may range from approximately 2 mm to approximately 10 mm. In another embodiment, the decorticator may have an outer radius of approximately 6 mm. 
     The abrasive distal end  1036  of the decorticator  1006  may include serrated teeth  1037  as shown, or may include a more flat annular surface with a gritty surface. In the embodiment shown in  FIG.  124   , the distal end of the tubular shaft portion  1034  is chamfered and the serrated teeth  1037  are located on the distal most end of the chamfered end allowing for a more directed and controllable decorticating process. As such, the decorticator  1006  shown is well suited for the intra facet process reflected by many of the embodiments described herein. That is, the human anatomy of the cervical spine may be such that the lateral mass of the facet joints are not perpendicular to the surface of the facet joint. Additionally, to properly place the forks  1012  of the delivery device  1004  within the joint, the delivery device  1004  may be positioned substantially parallel to articular surfaces of the facet joint. As such, the delivery device  1004  may not be positioned perpendicular to the lateral masses of the facet joints and may actually be directed with a downward slope as it extends in the distal direction. Where the decorticator  1006  has an non-chamfered annular end, depending on anatomy, the decorticator  1006  may be able to be placed in contact with the superior lateral mass, but may be unable to reach or contact the inferior lateral mass. In the present embodiment, the chamfered end of the tubular shaft portion  1034  will allow the distal tip of the chamfered end to reach and decorticate the inferior lateral mass. This chamfered distal end may define an angle to the longitudinal axis. In some embodiments this angle may range from approximately 10 degrees to approximately 80 degrees. In other embodiments, this angle may range from approximately 30 degrees to approximately 60 degrees. In other embodiments, this angle may be approximately 45 degrees. Additionally, the teeth  1037  may be relatively large as shown in  FIG.  124   , or they may relatively small. Moreover, the teeth  1037  may extend along the full perimeter surface of the chamfered end rather being positioned solely at the tip of the chamfered end. 
     Additionally shown in  FIG.  124    is a beveled edge  1039  along the periphery of the chamfered end. That is, along the ovular shape created by the chamfered tubular shaft portion  1034 , the edge is beveled. As such, when the delivery device  1004  is inserted into the patient and/or when the decorticator  1006  is advanced along the delivery device  1004 , the beveled edge  1039  may assist in avoiding tissue snags and the decorticator  1006  may be placed in contact with the lateral mass of the facet joints in a much smoother process and may avoid damage to neighboring tissues. 
     The handle  1038  of the decorticator  1006  may include a generally cylindrically shaped knob with a gripping surface along its peripheral edge and may sleevably receive the tubular shaft portion  1034 . The handle  1038  may also include radially extending bores  1041  adapted to receive the gripping tool  1001 . The bores  1041  may extend from the outer surface of the handle radially inward and end at the outer surface of the tubular shaft portion  1034 . As such, one or several gripping tools  1001  may be inserted into any one or several of the bores  1041  in the handle  1038  and may provide for better control and a higher amount of torsional leverage when decorticating the lateral masses of the facet joint. Additionally, the gripping tool  1001  extending laterally from the handle  1038  may allow for malleting in the longitudinal direction of the decorticator  1006 . That is, the gripping tool  1001  may be inserted into the bore  1041  and the decorticator  1006  may be advanced to contact the lateral mass of the facet joint. A mallet may be used to strike the side of the gripping tool  1001  to cause forceful decortication of the lateral mass. The decorticator may then be retracted, rotated to a new radial position, advanced, and struck again for additional decortication. In some embodiments, the handle  1038  may be shaped relatively oblong so as to provide a mass of material that extends laterally away from the longitudinal axis of the decorticator  1006 . In this embodiment, the bore  1041  may not be a radial bore  1041 , but may be offset from the passing through the center point of the decorticator  1006  a distance equal to or greater than a radius of the tubular shaft portion  1034 . As such, the bore may pass all the way through the handle without encountering the tubular shaft  1034 . Accordingly, the gripping tool may be inserted into the bore  1041  and extended all the way through the handle  1038 , allowing for additional ability to grip and/or mallet the gripping tool  1001  and manipulate the decorticator  1006 . 
     In still another embodiment, the bores  1041  may be positioned on the distal face of the handle  1038 . In this embodiment, the bores may receive the gripping tool  1001 , the tool being oriented parallel to the longitudinal axis of the decorticator  1006  and allowing for malleting the proximal end of the gripping tool  1001  to decorticate the lateral mass. In still another embodiment a series of gripping tools  1001  may be inserted into a series of bores  1041  positioned on the distal face of the handle  1038 , each available to be used for malleting or manipulating the decorticator  1006 . In still another embodiment, a single malleting tool (not shown) may be included, which has a series of longitudinally extending rods each receivable by a series of bores  1041  on the distal face of the handle  1038 . At a positioned proximal to the receiving assembly  1010  of the delivery device  1004 , the series of rods may converge to a centrally positioned malleting surface. As such, this malleting surface may be used to mallet the decorticator  1006  allowing for the force of the mallet to be positioned along the longitudinal axis of the decorticator. 
     Additionally shown in  FIG.  124    is a radially extending threaded bore  1047  adapted to receive a corresponding threaded set screw. This threaded bore  1047  may extend from the outer surface of the handle  1038  radially inward through the wall of the tubular shaft portion  1034  allowing access to the tubular shaft  1014  of the delivery device  1004 . The set screw may be advanced through the handle  1038  to engage the delivery device  1004  and prevent the decorticator  1006  from advancing or twisting inadvertently. As mentioned and shown in  FIG.  123   , the delivery device  1004  may include a groove  1021  on the outside surface of the tubular shaft  1014  for receiving the tip of the set screw or otherwise creating a catch point for the decorticator. As such, when the decorticator  1006  is in its fully retracted and most proximal position, the threaded bore  1047  and set screw may align with the groove  1021  in the tubular shaft  1014  and thus hold the decorticator  1006  in its most proximal position. The set screw may be a thumbscrew-type with a head that includes longitudinally extending ribs around its periphery for purposes of gripping the screw. Alternatively the head may be a wing nut type head for ease of setting and unsetting of the screw. In still another embodiment, the decorticator may have a relatively snug friction fit at the proximal end that engages the groove  1021  when retracted. In still another embodiment, the tubular shaft portion  1034  of the decorticator may include a protruding rib on its inside surface adapted to engage the groove  1021  on the tubular shaft  1014 . A key slot  1049  extending transversely across the threaded bore  1047  may also be provided. Additional features of the decorticator  1006  may include features of other decorticators shown and described herein. For example, the decorticator  1006  may alternatively be separate from the delivery device  1004  and may be slidably inserted within the delivery device  1004  similar to that shown and described with respect to  FIG.  4    or  FIGS.  6 A- 6 C . 
     Referring now to  FIG.  125   , the driver assembly  1042  is shown. As shown, the driver assembly  1042  includes a handle  1044 , an implant shaft  1046 , and implant holding arms  1048 . 
     The implant shaft  1046  may have an outer radius substantially equal to the inner radius of the tubular shaft portion  1014  of the delivery device  1004  (shown in  FIG.  123   ) allowing for slidable insertion of the driver assembly  1042  within the delivery device  1004 . Alternatively, the outer radius of the implant shaft  1046  may be smaller than the inner radius of the tubular shaft  1014  providing for more play and adjustability of the driver assembly  1042  and delivery device  1004  relative to one another. In some embodiments the implant shaft  1046  may have a radius ranging from approximately 1 mm to approximately 8 mm. In other embodiments, the implant shaft  1046  may have a radius of approximately 4 mm. 
     The handle  1044  of the driver assembly  1042  may have an outer surface defining a volume with a bore  1043  extending there through. The bore  1043  may have an inner diameter substantially equal to the inner diameter of the implant shaft  1046  allowing for a smooth transition of devices passing through the driver assembly  1042 . The handle  1044  may have a generally rectangular shape at its distal end corresponding to the proximal end of the receiving assembly  1010 . The handle  1044  may include gripping slots  1051  near its distal end to aid users with gloves in securely holding the driver assembly  1042 . Additionally, these slots  1051  may aid a user in hold the assembly  1042  with a hemostat or other gripping device. Additionally, the handle  1044  may have a necked down portion  1045  at its distal end in the form of one or more projections. In one embodiment, the necked down portion  1045  may have protrusions or recesses (not shown) on its outer surface corresponding to respective protrusions or recesses on the inner surface of the shell  1015  of the receiving assembly  1010  on the delivery device  1004 . As such, the driver assembly  1042  may be sleevably positioned within the delivery device  1004  to deliver an implant to the facet joint. When fully advanced, similar to that shown in  FIG.  101   , the handle  1044  may be seated securely in the seating cavity  1013  of the receiving assembly  1010 . Where protrusions are included on the necked down portion  1045  and recesses are included on the inner surface of the shell  1015 , the handle may be anchored with a detent relationship. The projections of the necked down portion  1045  of the handle  1044  may correspond to the seating cavities  1013  of the receiving assembly. Additionally, these projections may taper as they extend distally to provide a friction type fit into the seating cavities  1013  of the receiving assembly  1010 . 
     The seating relationship provided by necked down portion  1045  of the driver assembly  1042  and the receiving assembly  1010  of the delivery device  1004  may allow the user to control the placement of the implant in both a longitudinal and a rotational direction. That is, once the anchoring forks  1012  of the delivery device  1004  are properly placed in the facet joint, proper placement of the driver assembly  1042  may then be ensured by aligning and seating the handle  1044  of the driver assembly  1042  in the receiving assembly  1010  of the delivery device  1004 . Thus, the seating relationship may prevent the driver assembly  1042  from being inserted too far and may also allow the driver assembly  1042  to be aligned with the delivery device  1004  rotationally to ensure proper rotational orientation of the implant. Additional features of the driver assembly  1042  may include those features shown and described with respect to driver assembly  142 . 
     The implant holding arms  1048  may include features similar to other arms shown and described herein. For example, the inside surface of the arms  1048  may include a longitudinal ridge  1062  extending the length of the arms  1048 . The arms  1048  may also include a bull nose engagement feature  1058  extending transverse to the longitudinal axis of the implant shaft along the inside face of the arm  1048 . Where the arms  1048  are engaged with and holding the implant, the longitudinal ridges  1062  of each arm  1048  may be positioned between upper and lower planar members of the implant and the bull nose engagement features  1058  may be positioned in the U-shaped receiving feature slots on the lateral edges of the implant. 
     In contrast to the driver assembly  142  and consistent with the driver assembly  842 , each described above, in the present embodiment, the internal actuator  1052  may be a separate device from the driver assembly  1042 . As shown in  FIG.  126   , the internal actuator  1052  may include a longitudinal shaft  1055  a handle  1053 , and an internal rod  1057  (not shown in  FIGS.  126 - 126 B ). The longitudinal shaft  1055  may be cylindrically shaped with an annular cross-section. The shaft  1055  may have an outer diameter substantially the same as or smaller than the inner diameter of the implant shaft  1046  of the driver assembly  1042 . The shaft  1055  may extend from the handle  1053  proximally to a distal end. The internal actuator  1052  may be used in conjunction with the internal rod  1057  positioned within the shaft  1055 . 
     The internal rod  1057 , shown separately in  FIG.  127   , may be positioned within the shaft  1055  and may extend from the handle  1053  to the distal end of the longitudinal shaft  1055 . The internal rod  1057  may include an engagement feature  1059  at its distal end for engaging and holding the implant distractor. This engagement feature  1059  may be any shape and provide for any engagement known in the art from a hex, allen, phillips, star, square, sleeve, or other connection capable of transmitting longitudinal and/or rotational forces from the internal rod  1057  to the implant distractor. In one embodiment, the engagement feature  1059  includes a collet type device that is described in more detail with respect to  FIG.  127 A  below. 
     The internal rod  1057  may sleevably receive the implant distractor. The internal rod  1057  may be sleevably positioned within the longitudinal shaft  1055 , such that when the longitudinal shaft  1055  is in an advanced position over the end of the internal rod  1057 , the longitudinal shaft  1055  causes a clamping force of the collet to restrain the implant distractor against being dislodged from the collet. Each of the shaft  1055  and the internal rod  1057  may engage the handle  1053  at their respective proximal ends and be affixed there to. The shaft  1055  may be securely affixed to the handle  1053  such that rotational and longitudinal motion of the handle  1053  imparts the same motion on the shaft  1055 . In contrast, the internal rod  1057  may be slidably affixed to the handle  1053  such that rotational motion of the handle  1053  imparts the same motion on the internal rod  1057 , but longitudinal motion of the handle  1053  is isolated from the internal rod  1057  via a biasing mechanism. As such, the handle  1053  may be used to retract the longitudinal shaft  1055  along the length of the internal rod  1057  thereby exposing the collet and reducing the clamping force on the implant distractor, but when the handle  1053  is rotated, both the longitudinal shaft  1055  and internal rod  1057  rotate with the handle  1053 . When the longitudinal shaft  1055  is in a retracted position, an implant distractor may be inserted into and/or removed from the collet due to the reduced clamping force. 
     As shown in  FIGS.  126 A and  126 B , the handle  1053  may be a generally cylindrical shape with a cone shaped distal end and a relatively flat proximal end. As shown, the proximal end of the handle  1053  may include a circumferential ridge  1051  projecting proximally and extending along the periphery of the cylindrical shape. The inner face of the ridge may be braced by a plurality of radially spaced ribs  1061 . The center of the proximal end may include a button  1063  covered by a flexible membrane  1065 , the proximal end of the button  1063  being recessed slightly from the circumferential ridge  1051 , which protects the button  1063  against inadvertent triggering when the handle  1053  is being used to twist or turn the implant distractor. As such, the handle  1053  shown may reduce the chance that the implant distractor will become dislodged or released from the engagement feature  1059  of the internal actuator  1052  prior to being fully advanced and fully distracting the implant. 
     As shown in the cross-section of the handle  1053  in  FIG.  126 B , the button may be held in position by an internal spring  1067  or other biasing mechanism or device and may also include longitudinal keyways allowing for relative longitudinal motion of the button relative to the handle  1053 , but preventing relative rotational motion. In use, the implant distractor may be placed in the engagement feature  1059  at the distal end of the internal rod  1057  and the internal rod  1057  may be in position inside the longitudinal shaft  1055 . As mentioned above, in the embodiment, shown, when the internal rod  1057  has a collet type engagement feature  1059 , the retraction of the internal rod  1057  within the longitudinal shaft  1055  may cause a circumferential clamping force from the longitudinal shaft  1055  onto the engagement feature  1059  of the internal rod  1057 , thereby securing the implant distractor in the engagement feature  1059  of the internal rod  1057 . Once assembled, the internal actuator  1052  may be inserted and advanced through the driver assembly  1042  positioning the implant distractor just proximal to the implant being held by the implant holder arms of the driver assembly. The handle  1053  may then be rotated to cause the implant distractor to advance into the implant thereby distracting the implant. 
     Once the implant distractor is fully advanced, the handle  1053  may be grasped and the button may be pressed, while pulling on the cone shaped portion of the handle  1053 , which may counteract the biasing force of the spring  1067  or other biasing mechanism and cause relative longitudinal motion between the internal rod  1057  and the longitudinal shaft  1055 . Accordingly, the distal end of the internal rod  1057  may extend beyond the distal end of the longitudinal shaft  1055  and the clamping force on the engagement feature  1059  may be removed allowing the internal actuator  1052  to be removed leaving the implant distractor behind. 
     As shown in more detail in  FIGS.  127  and  127 A , the engagement feature  1059  at the distal end of the internal rod  1057  may take the form of a collet  1093  for holding the implant distractor. The collet  1093  may be affixed to the distal end of the internal rod  1057  and may be adapted to hold the implant distractor. The collet  1093  may be permanently affixed to the distal end of the internal rod  1057  or may be interchangeably coupled thereto. Several collet and chuck arrangements are known in the tool industry for receiving bits or other devices and are within the scope of the invention. 
     The collet  1093  may include any or all of the features of other collets shown and described herein. For example, the collet  1093  may include a generally cylindrical body member  1095  with four receiving fingers  1097  equally spaced around a bore  1099 . The collet  1093  may include as few as two fingers  1097  and may include any number of fingers  1097 . 
     In still another embodiment, a second internal actuator may be provided. This second internal actuator may include a handle securely affixed to a shaft and an engagement feature securely affixed to a distal end of the shaft. The engagement feature may correspond to the shape of the proximal end of the implant distractor. In one embodiment, this shape is a female square shape corresponding to a square shaped proximal end of the implant distractor. This engagement feature may include any shape known in the art as mentioned with respect to the engagement feature  1059  discussed above. This second internal actuator may be used to advance the implant distractor. For example, the second internal actuator may be used if the internal actuator  1052  were to lose its grip on the implant distractor. That is, if the collet loses its grip for any reason including deformation of the fingers of the collet or due to malfunction of the internal actuator  1052  for any reason, the second internal actuator may be used. The second internal actuator may be passed down the tubular shaft  1046  of the driver assembly  1042  to engage the proximal end of the implant distractor. The engagement feature on the distal end of the second internal actuator may be brought into engagement with the proximal end of the implant distractor and the second implant distractor may be used to rotate or otherwise advance the implant distractor thereby distracting the implant. 
     Turning now to  FIG.  128   , an injector  1102  is shown. The injector  1102  may include a longitudinal delivery shaft  1117 , a seating feature  1119 , and a plunger  1123  with a handle  1125 . The longitudinal delivery shaft  1117  may have any cross-section and may have a cross-sectional size adapted to fit within the delivery device  1004 . The longitudinal shaft  1117  may have an opening  1127  on its distal end for directing bone paste out the distal end of the shaft  1117  allowing the paste to flow into and/or over the facet joint and/or outward toward the lateral mass of a facet joint. The seating feature  1119  may include a rectangular or other shaped block positioned around the shaft  1117 , which may be sized and shaped to abut the receiving assembly  1010  of the delivery device  1004 . As with the driver assembly  1042 , the distal end of the seating feature  1119  may have a shape corresponding to the shape of the proximal end of the receiving assembly  1010 . As shown, this is a generally rectangular shape, but may be any shape. Additionally, the seating feature  1119  may include gripping slots  1027  nears its distal end. Additionally, the seating feature  1119  may include a necked down portion  1025  on its distal end which may be received by the seating cavities  1013  of the receiving assembly  1010 . As with the driver assembly  1042 , the seating feature  1119  of the injector  1102  may include protrusions or recesses (not shown) corresponding to protrusions or recesses on the inner surface of the shell  1015  allowing for a detent relationship for securing the injector  1102  to the delivery device  1004 . 
     The injector  1102  may be sleevably inserted into the delivery device  1004  and advanced such that the distal end of the shaft  1117  is positioned between the forks  1012 . The plunger handle  1125  may be pressed distally and bone paste or other material may be injected toward the facet joint site. Additional features not mentioned may be included as shown and described with respect to the injector  202  and/or  902 . For example, the plunger  1123  may include a seal. 
     A gripping tool  1001  has been referenced for use with several of the above devices, including, but not limited to the chisel  1008  and the decorticator  1006 . As shown in  FIG.  121   , the gripping tool  1001  may include a shaft  1003  and a handle  1005 . The shaft  1003  may be made of a relatively rigid material and may have a diameter adapted to fit into the bores provided in the chisel  1008  and the decorticator  1006 . The handle  1005  of the gripping tool  1001  may be any shape. In one embodiment, the handle  1005  is a T-type handle  1005 . In another embodiment, as shown, the handle  1005  is a spherically shaped handle  1005 . The handle  1005  may be adapted in size and shape to nest in the palm of a human hand and such that it can be used to push, pull, or rotate the devices it is connected to or be struck with a mallet. 
     Referring now to  FIGS.  129 - 135 B , a dilator set  1200  is shown.  FIGS.  129 - 131    show an assembled set of dilators including a dilator rod  1202  and a plurality of dilator sleeves  1204 , including a small  1204 A, medium  1204 B, and large  1204 C dilator. Any number of dilator sleeves  1204  may be included. Each of the dilator sleeves  1204  may have an inner diameter corresponding to the outer diameter of the next smallest sleeve, the smallest sleeve  1204 A having an inner diameter corresponding to the outer diameter of the dilator rod  1202 . Each of the dilator sleeves  1204  and dilator rod  1202  may have varying lengths, the largest of the sleeves  1204 C having the shortest length, the dilator rod  1202  having the longest length, and the other sleeves  1204 A,  1204 B having lengths there between, such that each rod  1202  or sleeve  1204  is longer than the next largest sleeve. Each of the dilator rods  1202  and sleeves  1204  may include a tapered tip. 
     As shown in  FIGS.  132  and  132 A , the dilator rod  1202  is shown. The dilator rod  1202  may be a generally solid shaft or may include an interior lumen for receiving a guide wire. The rod  1202  may have any outer diameter. In one embodiment, the rod  1202  has an outer diameter of between approximately 1 mm and 5 mm. In another embodiment, the rod  1202  has an outer diameter of approximately 3 mm. The rod  1202  may have any length. In one embodiment, the rod  1202  has a length of between approximately 200 mm and 400 mm. In another embodiment, the rod  1202  has a length of approximately 290 mm. The tip of the rod  1202  may be tapered and may further include a radiused distal tip. As such, the tip may be adapted to penetrate and dilate tissue. 
       FIGS.  133 ,  133 A, and  133 B  show the small dilator sleeve  1204 A. The small sleeve  1204 A may have an inner diameter adapted to slide over the dilator rod  1202 . The inner diameter of the small sleeve  1204 A may be only slightly larger than the rod diameter or may be much larger. In one embodiment, the inner diameter of the small sleeve  1204 A is 0.6 mm larger than the dilator rod diameter. The small sleeve  1204 A may have any outer diameter and any length. In one embodiment, the small sleeve  1204 A has an outer diameter of between approximately 3 mm and 9 mm. In another embodiment, the small sleeve  1204 A has an outer diameter of approximately 6 mm. In one embodiment, the small sleeve  1204 A has a length of between approximately 200 mm and 300 mm. In another embodiment, the small sleeve  1204 A has a length of approximately 260 mm. The small sleeve  1204 A may include a tapered tip with a radiused distal edge and, as such, the small sleeve may be adapted to slide over the dilator rod and further dilate tissue. 
       FIGS.  134  and  134 A  and  FIGS.  135 ,  135 A, and  135 B , show a medium dilator sleeve  1204 B and a large dilator sleeve  1204 C respectively. The medium sleeve  1204 B may have an inner diameter adapted to slide over the small sleeve  1204 A and the large sleeve  1204 C may have an inner diameter adapted to slide over the medium sleeve  1204 B. Each of the medium sleeve  1204 B and large sleeve  1204 C may have an inner diameter only slightly larger than the outer diameters of the small  1204 A and medium  12048  sleeve respectively or they may have an inner diameter that is much larger. In one embodiment, the medium sleeve  1204 B and the large sleeve  1204 C may have an inner diameter that is approximately 0.6 mm larger than the outer diameter of the small sleeve  1204 A and the medium sleeve  1204 B respectively. The medium sleeve  1204 B may have any outer diameter and any length. In one embodiment, the medium sleeve  1204 B has an outer diameter of between approximately 4 mm and 12 mm. In another embodiment, the medium sleeve  1204 B has an outer diameter of approximately 8 mm. In one embodiment, the medium sleeve  1204 B has a length of between approximately 180 mm and 280 mm. In another embodiment, the medium sleeve  1204 B has a length of approximately 230 mm. The large sleeve  1204 C may also have any outer diameter and any outer length. In one embodiment, the large sleeve  1204 C has an outer diameter of between approximately 6 mm and 18 mm. In another embodiment, the large sleeve  1204 C has an outer diameter of approximately 11 mm. In one embodiment, the large sleeve  1204 C may have a length of between approximately 150 mm and 250 mm. In another embodiment, the large sleeve  1204 C may have a length of 200 mm. Each of the medium  1204 B and large  1204 C sleeves may include a tapered tip with a radiused distal edge. As such, each of the medium  1204 B and large  1204 C sleeves may be adapted to dilate tissue slightly more than the corresponding smaller sleeve. 
     In use, the dilator set of  FIGS.  129 - 135 B  may be used to dilate tissues to access a facet joint. That is, once an incision is made, the dilator rod  1202  may be advanced alone or over a guidewire through the tissues of the back up to and/or into the facet joint. Once the rod  1202  is in position, the small sleeve  1204 A may be advanced over the rod  1202  from the proximal end of the rod  1202  and may be advanced along the full length of the rod  1202 . The longer length of the rod  1202  may allow the rod  1202  to extend out of the proximal end of the small sleeve  1204 A such that control of both elements of the dilator set are maintained. The small sleeve  1204 A may be advanced fully such that the tip of the small sleeve  1204 A is flush with the tip of the rod  1202 , thus dilating the tissues in an amount equal to the outer diameter of the small sleeve  1204 A. This process may continue with larger and larger sleeves  1204  to appropriately dilate the tissues and allow access to the facet joint. Depending on the dilation necessary, the order and type of dilation may vary. That is, in some instances, the rod may not be necessary. In other instances, some of the sleeves may be omitted or skipped. 
     Referring now to  FIGS.  136 - 170   , another embodiment of a tool  2000  is shown.  FIG.  136    shows a chisel  2008 , a place holding chisel  2009 , a delivery device  2004 , a decorticator  2006 , a driver assembly  2042 , an injector  2102 , and a malleting tool  2001 . 
     Referring more particularly to  FIGS.  138 - 143   , a chisel  2008  may be the same or similar to other chisel embodiments described herein. For example it may have a tubular shaft portion  2028  and tip portion  2030  the same or similar to the chisel  1008  described above. Additionally, the chisel  2008  may include a handle  2032  the same or similar to the handle  1044  on the driver assembly  1042 . However, in contrast to the driver assembly handle  1044 , the chisel handle  2032  may include a recessed slot cavity on its distal face for receiving a malleting anvil  2041  of the receiving assembly  2010 . The handle  2032  can also include a malleting head  2031  for advancing the chisel  2008  via malleting. 
     With reference to  FIGS.  140 - 141   , one embodiment of the malleting head  2031  is shown. The malleting head  2031  can include a cylindrical shaft portion  2051  and a flattened circular head portion  2053 . The cylindrical shaft portion  2051  can be sized for sleevable insertion into the proximal face of the handle  2032 . Additionally, the cylindrical shaft portion  2051  can include a key slot  2055  extending longitudinally along its length. The key slot  2055  can be adapted to receive a longitudinal rib on an inner surface of a bore extending through the handle  2032 . Accordingly, the malleting head  2031  can be prevented from twisting relative to the handle  2032  once assembled. Additionally, as shown in  FIG.  141    the malleting head  2031  can include a flattened surface on the inner surface of the cylindrical shaft portion  2051 . As shown in  FIG.  142    the proximal end of the shaft portion  2028  of the chisel  2008  can include a corresponding flattened portion. Accordingly, once assembled, the shaft portion  2028  of the chisel  2008  can be prevented from twisting relative to the malleting head  2031 . The malleting head  2031  can also include a counter bored hold extending into the circular head portion  2053  and the proximal end of the shaft portion  2028  of the chisel  2008  can include a corresponding pilot hole. Accordingly, once assembled, a screw can be inserted in the proximal end of malleting head  2031  and can extend into the proximal end of the shaft portion  2028  of the chisel  2008  thereby securing the two portions to one another. 
     As shown in  FIGS.  139 A- 139 C , the proximal end of the shaft portion  2028  of the chisel  2008  can extend through the distal face of the chisel handle  2032 . The distal end of the malleting head  2031  can extend through the proximal face of the chisel handle  2032  until the bottom face of the circular head abuts the proximal surface of the handle  2032 . The proximal end of the shaft portion  2028  can be sleevably positioned within the cylindrical shaft portion  2051  of the malleting head  2031  and a screw can secure the malleting head  2031  to the shaft portion  2028  of the chisel  2008 . In alternative embodiments, the shaft portion  2028  can be integral with the malleting head such that the two portions of the chisel are monolithic. It is noted, in the embodiment described, that once assembled, the malleting head  2031  can extend beyond the base of the slot cavity of the handle  2032 . The malleting head  2031 , being positioned on the proximal face of the handle  2032  and being directly attached to the shaft portion, can provide for forces from malleting the head  2031  of the chisel  2008  to transfer directly down the shaft portion  2028  of the chisel. Moreover, the distal end of the malleting head  2031 , extending slightly beyond the base of the slot cavity, can allow the malleting head  2031  to directly abut the malleting anvil  2041  of the receiving assembly  2010  when the chisel  2008  is inserted into the deliver device  2004  as shown in  FIG.  144   . As such, when the malleting head  2031  of the chisel  2008  is struck, any advancing force of the chisel  2008  relative to the delivery device  2004  can be resisted by the interaction between the malleting head  2031  and the malleting anvil  2041  thereby preventing relative advancing motion between the chisel  2008  and the delivery device  2004 . 
     Referring to  FIGS.  145  and  149   , the distal end of the chisel  2008  is shown extending slightly beyond the distal tip of the delivery device  2004 . In some embodiments, the distal end of the chisel  2008  can be flush with the distal tip of the delivery device  2004  or it can extend up to approximately 6 mm beyond the end of the delivery device  2004 . In the embodiment shown, the distal end of the chisel  2008  extends approximately 2 mm beyond the end of the delivery device  2004 . 
     As also shown in  FIG.  149   , the surfaces of the tip  2030  of the chisel can include a series of ridges  2033 . The ridges  2033  can be relatively sharp and can aid the user in roughening or decorticating the facet surfaces as the chisel  2008  is inserted and removed from a facet joint. The ridges  2033  can include a pattern adapted to maintain the chisel&#39;s position in a facet joint. In some embodiments, the ridges  2033  can include a sloping distal face and a relatively vertical (e.g., perpendicular to axis of chisel  2008 ) proximal face. As the chisel  2008  is advanced, the surfaces in contact with the chisel  2008  may ride up along the sloping distal face until the chisel  2008  is positioned. The relatively sharp apex of the ridges  2033  formed by the sloping distal face and relatively vertical proximal face can function to hold the chisel in place. Moreover, the ridges  2033  can be arranged in a surface pattern suitable for holding the chisel  2008  in place. In one embodiment, the ridges  2033  can include a chevron pattern as shown. Patterns such as straight rows, diagonal rows, wavy rows, or other alternative patterns can be included. 
     Referring particularly to  FIG.  143   , the distal end of the chisel can include a positioning opening  2059 . The positioning opening  2059  can extend transversely through the chisel  2008  and can be positioned near the proximal portion of the tip  2030  of the chisel  2008 . This opening  2059  can function to allow for longitudinal positioning of the chisel  2008  through lateral fluoroscopy. That is, the opening  2059  can be visible during lateral fluoroscopy due to the absence of material and the chisel  2008  can be advanced into a facet joint until the opening  2059  is at, near, or slightly beyond the posterior edge of the facet joint. It is noted that the position of the opening  2059  can be such that it aligns with a corresponding opening  2015  in the forks  2012  of the delivery device  2004 . 
     Referring to  FIG.  138   , the handle  2032  can include connection features  2043  on the necked down portion of the handle  2032 . The connection features  2043  can create a detent relationship between the handle  2032  and the receiving assembly  2010  of the delivery device  2004  such that the two elements can resist separation without some force being applied. The detent relationship can be created by protrusions as shown, which engage a lip around the proximal end of the receiving assembly  2010  or a recess on the inner surface of the receiving assembly  2010 . Alternatively, the detent relationship can be created by recesses for receiving protrusions positioned on the inner surface of the receiving assembly  2010 . 
     Referring to  FIGS.  139 A-C ,  159 , and  155 A-B, the connection feature  2043  can also take the form of a latch type feature. For example, the feature  2043  can be wedge shaped and adapted to engage a corresponding ledge on the inside of the receiving assembly  2010 , as best shown in  FIG.  1556   . The connection feature  2043  can be positioned on a deflectable lateral side of the handle  2032  and the deflectable lateral side can include a push button for disengaging the connection feature  2043 . When the chisel  2008  is advanced into the delivery device  2004 , the deflectable lateral side of the handle  2032  can deflect to allow the connection feature  2043  to clear the opposing and corresponding ledge on the inside of the receiving assembly  2010  allowing the handle  2032  to snap into place in the receiving assembly  2010 . To remove the chisel  2008 , the push button can be depressed to clear the connection feature  2043  from the corresponding ledge and the chisel  2008  can then be removed. It is noted that a similar connection can be used on any of the handles or seating features described herein; particularly handles or seating features adapted to engage the receiving assembly  2010 . 
     In this embodiment, the chisel  2008  may be engaged with the delivery device  2004  via a connection between the handle  2032  and the receiving assembly  2010 . In this embodiment, both the chisel  2008  and the delivery device  2004  may be introduced into the facet joint at the same time allowing for a one-step process of initially entering the facet joint rather than initially entering the joint with the chisel  1008  and then passing the delivery device  1004  over the chisel  1008  as with the tool  1000 . Once the chisel  2008  and the deliver device  2004  are properly positioned, the chisel  2008  may be removed. 
     As shown in  FIG.  136   , the tool  2000  can also include a place holding chisel  2009 . The place holding chisel  2009  can have a square cross-section adapted to be inserted into the delivery device  2004 . The diagonal dimension of the cross-section can be at least slightly smaller than the inner diameter of the delivery device  2004 . Alternatively, other cross-sections can be provided and can be adapted for insertion in the delivery device  2004 . 
     The place holding chisel  2009  can be a radiolucent chisel and as such can be made from a radiolucent material such as plastic, PEEK, or a polyetherimide material such as, for example, Ultem®. Other radiolucent materials can be used. The place holding chisel  2009  may include a positioning marker  2011  adapted to assist the user in properly positioning the place holding chisel  2009 . The positioning marker  2011  can include a guide line, a mark, or another surface indication on the surface of the chisel  2009  for alignment with a portion of the delivery device  2004 . In one embodiment, as shown, the positioning marker  2011  can be in the form of a double triangle separated by an alignment line. The double triangles can be positioned to form an alignment line on the place holding chisel  2009  such that when the alignment line is aligned with the proximal end of the delivery device  2004  (e.g., the proximal face of the receiving assembly  2010 ), the distal end of the chisel  2009  is properly positioned to extend slightly out the end of the delivery device  2004 . Additionally, where the alignment line is not aligned with the distal end of the delivery device  2004 , the triangles can function as arrows indicating which direction to move the chisel  2009 . That is, the triangle closest to the distal face of the receiving assembly, may indicate which direction to move the chisel  2009 . As also shown, the proximal end of the chisel  2009  can include a hole extending transversely there through. The hole can adapted to receive a transverse rod or shaft extending into the hole and/or through the hole. The rod or shaft and the chisel  2009  can form a T-grip or L-shaped grip for use in pulling on the chisel  2009  for removal. 
     Referring again to  FIG.  149   , the distal tip of the place holding chisel  2009  can include a tip the same or similar to the chisel  2008 . For example, the chisel  2009  can include a coped and/or chamferred tip  2035  similar to chamferred tip  2030 . Additionally, the chisel  2009  can include ridges  2037  arranged in a pattern similar to that shown and described with respect to chisel  2008 . Additionally, the chisel  2009  can include a radiopaque portion  2039  adapted to allow recognition of the chisel&#39;s location while avoiding occlusion of the lateral view. The radiopaque portion  2039  can include a straight, round, square, or other shaped piece of material positioned near the distal end of the chisel  2009  for locating the distal end. As shown, the radiopaque portion  2039  can be embedded in the surface of the distal tip of the chisel  2009  to cause the location of the distal tip to be ascertainable from lateral fluoroscopy. 
     In use, the place holding chisel  2009  can be used as a place holder without occluding the lateral view of a chisel and delivery assembly positioned in a contralateral facet joint. That is, upon placement of the chisel  2008  and the delivery device  2004  in a first facet joint, the chisel  2008  may be removed and replaced with the place holding chisel  2009  where the forks  2012  of the delivery device  2004  maintain the position of the tool  2000 . The delivery device  2004  may also be removed and reassembled with the chisel  2008  once the place holding chisel  2009  is properly positioned. The delivery device  2004  and chisel  2008  may then be inserted into the contralateral facet joint or second joint. By replacing the chisel  2008  in the first joint with the place holding chisel  2009 , the location of the chisel  2008  and delivery device  2004  in the second joint may be more readily ascertainable using lateral fluoroscopy. That is, if a radiopaque chisel or delivery device was left in place in the first joint, the fluoroscopic view of the contralateral facet joint would be relatively occluded. Upon placing the delivery device  2004  properly in the second facet joint, the procedure above may continue. Upon completing treatment of the second facet joint, the delivery device  2004  may be sleeved over the place holding chisel  2009  still positioned in and holding the place in the first facet joint and the first facet joint may then be treated with the above procedure. It is noted that initial placement of the deliver device  2004  can be conducted with the place holding chisel  2009  rather than the chisel  2008  to avoid having to replace the chisel  2008 . Additional features of the chisel  2008  may include features of the other chisels shown and described herein. For example, an internal lumen may be provided. 
     Referring now to  FIGS.  137  and  144   , a delivery device  2004  is shown. The delivery device  2004  may include features the same as or similar to previously disclosed delivery devices. For example, the delivery device  2004  can include a receiving assembly  2010  at a proximal end and a pair of anchoring forks  2012  at a distal end with a generally tubular shaft  2014  extending there between. The delivery device  2004  can also include a malleting anvil  2041 . The malleting anvil  2041  can include a raised surface positioned on the proximal face of the receiving assembly  2010  adapted for contact with the distal end of the malleting head  2031  on the chisel  2008 , as described above, or on the driver assembly  2042 . As such, malleting on the proximal end of the chisel  2008  or the driver assembly  2042  can cause longitudinal forces along the length of the respective tool piece. These longitudinal forces can be transferred, at least partially, through the contact between the malleting head  2031  and the malleting anvil  2041 . Accordingly, relative motion between the respective tool piece and the delivery device  2004  can be prevented. As such, for example, the necked down portion  2045  of the driver assembly, can be prevented from wedging inside the receiving assembly and getting lodged or stuck therein. Moreover, at the distal end of the delivery device  2004 , the relative position of the distal end of the chisel  2008  or the driver assembly  2042  relative to the distal end of the delivery device  2004  can be maintained. 
     Referring now to  FIGS.  145  and  149   , a distal tip of the delivery device  2004  is shown. As shown, the distal tip of the delivery device  2004  can include anchoring forks  2012 . As shown, and previously described, the forks  2012  can include teeth or ridges along their surface for decorticating the interior surface of the facet and for temporarily anchoring the delivery device  2004  therein. In this embodiment, the teeth or ridges can extend along and across the coped portion of the tubular shaft  2014  of the delivery device  2004 . This coped portion can be tapered to avoid hanging up on the lateral mass of the facet joint. That is, as the forks  1012  are inserted into the joint the outward sloping portion of the distal end of the delivery device  2004  can approach the lateral mass of the joint. Where the coped portion slopes too abruptly, the contact between the sloped surface and the lateral mass can limit how far the forks  2012  can be advanced into the joint. In some embodiments, the coped portion of the distal end of the delivery device  2004  can include a taper angle  2013  ranging from approximately 5.degree. to approximately 45.degree. Preferably, the taper angle  2013  is approximately 7.degree. to approximately 15.degree. The taper angle can be adjusted to accommodate several different types and/or areas of the anatomy and can thus also include angles outside the mentioned ranges. For example, use of the device in the lumbar region of the spine may involve the use of different angles. 
     With continued reference to  FIGS.  145  and  149   , along the lateral side of the tubular shaft portion  2014  near the proximal end of the forks  2012 , the tubular shaft portion  2014  can include an alignment hole  2015 . This alignment hole  2015  can align with the positioning opening  2059  in the chisel  2008  and can be used with lateral fluoroscopy for properly advancing the delivery device  2004  and/or the chisel  2008 . As discussed with respect to the chisel  2008 , the delivery device  2004  can be advanced until the alignment hole  2015  is just outside, at, or just inside the posterior edge of the facet joint. 
     In addition to the alignment hole  2015 , near the intersection of the forks  2012  and the tubular shaft portion  2014 , a bump or bull nose  2049  can be provided to further assist with properly placing the delivery device  2004 . The bump  2049  can be in alignment with the alignment hole  2015  and can serve a similar purpose as the alignment hole. Thus, the bump or bull nose  2049  can function to assist the user in properly advancing the delivery device  2004  where the alignment hole  2015  is blocked, or not provided, or in addition to the alignment hole  2015 . The bump  2049  can accentuate the location of the proximal end of the forks  2012  and the bumps position relative to the posterior edge of the facet joint can indicate to the user whether the forks  2012  are properly positioned. In some embodiments, the bump can also function to secure the forks  2012  in the facet joint. That is, as the delivery device  2004  is advanced into the joint, the bump or bull nose  2049  can be advanced just beyond the posterior edge of the articular surface of the facet joint. This articular surface can be relatively concave and the shape of the bump or bull nose  2049  can function to hook itself just inside the perimeter of the concave surface and resist withdrawal of the delivery device  2004 . 
     The generally rectangular cross-section of the proximal portion of the receiving assembly  2010  may have a long side and a short side. The long side may be oriented perpendicular to a line connecting the forks  2012 . This may be in contrast to the previously described embodiments, where the long side was shown parallel to a line connecting the forks  2012 . In some embodiments, particularly where two contralateral facet joints are being treated, the shown orientation can assist in avoiding interference of adjacent handles. That is, the shown orientation can allow the forks of the delivery device  2004  to be inserted into the facet joint and the receiving assembly  2010  can maintain a vertical orientation relative to the patient allowing the nearby joint to be treated without interference with the receiving assembly  2010 . In the present tool assembly  2000 , the tool pieces adapted for insertion into the deliver device  2004  can also have a handle portion such as, for example, handle  2032  and/or  2044  that is oriented perpendicular to the chisel distal tip or the holding arms  2048  respectively. As such, devices used with the delivery device  2004  may be properly aligned relative to the forks  2012  by positioning and seating them in the seating cavities  2013  of the receiving assembly. 
     Referring now to  FIG.  146   , a decorticator  2006  is shown. The decorticator  2006  shown can include a malleting element  2038  at its proximal end and a series of decorticating teeth  2037  on a distal end. The malleting element  2038  and the teeth  2037  can be connected by a generally U-shaped and relatively thin longitudinally extending member  2034 . The malleting element  2038  can include a relatively thick generally U-shaped member. As shown, the malleting element  2038  and the longitudinal member  2034  can be aligned and adapted to receive a tube from the lateral side. That is, for example, the decorticator  2006  can be applied to the delivery device  2004  from the side rather than being sleeved over the delivery device as shown in previous embodiments. The malleting element  2038  can be used for forcibly advancing the decorticator  2006 . Accordingly, the malleting element can be a relatively thick element adapted to absorb and distribute a malleting force to the longitudinal member  2034 . The teeth  2037  can be the same or similar to the decorticating teeth previously described, such as, for example, the serrated teeth  1037 . The teeth  2038  can be positioned along all or a portion of the half annular shape formed by the distal end of the U-shaped longitudinal member  2034 . As with the decorticator  1006 , the present decorticator  2006  can include a chamferred distal end allowing for acute decortication by the teeth  2037  without interfering with adjacent or surrounding structures. For example, decorticator  2006  can allow for access to the inferior lateral mass without interference from the superior lateral mass of a facet joint due to the chamferred distal end and also due to the u-shape. The decorticator can include features that are the same or similar to the decorticators previously described. 
     The malleting element  2038  can be used with a malleting tool  2001  as shown in  FIGS.  136  and  150   . As shown best in  FIG.  136   , the malleting tool  2001  can include a longitudinally shaped shaft with a U-shaped decorticator interface  2005  at one end and a chamferred tip  2003  at the other end. The decorticator interface  2005  can be adapted for positioning around the delivery device  2004  in a position just proximal to the malleting element  2038  of the decorticator. The u-shape of the decorticator interface  2005  may allow the malleting tool  2001  to be placed in position from the side of the delivery device and selectively used as required to forcibly advance the decorticator  2006 . The chamferred end of the tool  2001  can be held in position while the user mallets near the decorticator interface end causing the interface  2005  to contact the malleting element  2038  on the decorticator. The decorticator  2006  may then be retracted, rotated to a new radial position, advanced, and struck again for additional decortication. The tool  2001  may rotate with the decorticator  2006  or it may remain in a position convenient for malleting. In addition to malleting, the malleting tool  2001  can be used to assist in separating several tools. That is, in some cases, the handles of a given tool piece, for example, the handle  2032  of the chisel  2006  can be difficult to separate from the receiving assembly  2010 . As mentioned, the malleting tool can include a chamferred tip  2003 . The chamferred tip can be used to wedge between a given handle and the receiving assembly  2010  to assist in separating the devices. 
     Referring now to  FIGS.  147  and  148   , a driver assembly  2042  is shown. As shown, the driver assembly  2042  includes a handle  2044 , an implant shaft  2046 , implant holding arms  2048 , and an integrated internal actuator  2052 . 
     The handle  2044  of the driver assembly  2042  may include features the same or similar to previously described handles. In particular, the handle  2042  can include features the same or similar to the driver assembly handle  1042 . In the present embodiment, the handle can also include a slot cavity, similar to the chisel  2008 , for receiving and interfacing with the malleting anvil  2041  on the proximal end of the receiving assembly. 
     Where the driver assembly  2042  is sleevably positioned within the delivery device  2004 , the necked down portions  2045  of the handle  2044  can be received into the receiving assembly  2010  and the slot cavity can be positioned around the malleting anvil  2041  on the proximal face of the receiving assembly. Similar to the chisel  2008 , the slot cavity on the handle  2044  can include a bearing surface  2047  for interfacing with the malleting anvil  2041 . In addition, the handle  2044  can include a malleting bar  2043  extending distally from a first side of the body of the handle, laterally across the width of the body of the handle, and then proximally to a second side of the handle. The malleting bar  2043  may allow for malleting of the driver assembly  2042  and the interaction of the bearing surface with the malleting anvil can function to prevent relative longitudinal motion between the driver assembly  2042  and the delivery device  2004  when malleting the driver assembly. Additionally, as described with respect to the chisel  2008 , the handle  2044  can include connection features  2043  providing for a detent relationship with the receiving assembly  2010  or the latch type connections can be provided. 
     The integrated internal actuator  2052  can include features the same or similar to the internal actuator  1052 . In the present embodiment, the actuator can be integrated into the driver assembly  2042  and can be securably and pivotally positioned therein. For example, when compared to the internal actuator  852  and/or  1052 , the tubular shaft  855 / 1055  can be omitted and an internal rod  2057 , the same or similar to rods  857  and  1057 , can be positioned within the implant shaft  2046  of the driver assembly. As mentioned with respect to internal actuator  152 , the distal tip of the internal actuator can include flat screwdriver types, phillips head types, square drives, etc. As best shown in  FIG.  148   , the distal tip of the internal actuator  2052  can be a flat screwdriver type tip. 
     The handle  2053  can be pivotally secured to the handle  2044  of the driver assembly  2042  allowing for pivotal motion of the handle  2053  relative to the implant shaft  2046  causing rotation of the internal rod  2057 . As shown, the handle  2053  can be positioned just proximal to the body of the handle  2044  and the malleting bar  2043  can extend around its perimeter. A gap may be provided between the malleting bar  2043  and the handle  2053  to avoid interference with the rotation of the handle  2053  and to avoid transferring malleting force through the internal actuator. The handle  2053  can be adapted to advance as it is turned and can further be adapted to properly advance the implant distractor  2050 . That is, the clearance provided within the handle  2044  can be such that a particular advancing distance of the handle  2053  will cause the handle  2053  to interact with or abut the handle  2044  preventing over-advancing the internal rod  2057  and the implant distractor  2050 . This allows the advancement of the implant distractor  2050  and the associated distraction of the joint with the implant to be reproducible and consistent. In one embodiment, the implant distractor  2050  is advanced to a point where a cross-cut of a thread feature on the implant distractor  2050  engages a truncated slot on the implant. In one embodiment, the implant distractor  2050  can be started in the implant by 1½ turns prior to insertion of the driver assembly  2042  in the delivery device  2004  where the leading portion of the thread feature on the implant distractor  2050  is engaged in the leading slot on the implant. The turning of the handle  2053  can then advance the implant distractor  2050  the remaining distance relative to the implant. 
     The implant holding arms  2048 , shown most clearly in  FIG.  149    may include features similar to other arms shown and described herein. For example, an engagement feature  2058  similar to the bull nose engagement feature  1058  may be provided. In the present embodiment, the engagement feature  2058  can include a raised portion on the surface of the holding arms  2048  that can be adapted to be positioned in the U-shaped receiving feature slots on the lateral edges of the implant. The present embodiment can be contrasted with the arms  1048  shown in  FIG.  125   . As shown, the arms  2048  are adapted to be positioned within the implant and do not extend along side the implant. This can allow for a narrower transverse dimension and an overall smaller system. The arms  2048  can include steps as the arms transition from the implant shaft  2046  of the driver assembly to the arms  2048 . The step can be adapted to accommodate the thickness of one of the upper and/or lower members of the implant such that, when placed thereon, an outer surface of the implant can be relatively flush with the upper level of the step. 
     The interaction of the driver assembly  2042  with the deliver device  2004  can function to properly position the implant. That is, both the alignment hole  2015  and the bump or bull nose  2049  can function to properly position the delivery device  2004  as described above. The driver assembly  2042  can include a length and handle engagement adapted to position the implant between the forks  2012  of the delivery device  2004  by fully inserting the driver assembly  2042  in the delivery device and engaging the connection features. Accordingly, the driver assembly  2042  can allow the implant to be positioned anterior to the alignment hole  2015  and/or the bumps  2049  of the delivery device  2004  and thus can be used to properly position the implant. This engagement of the handle of the driver assembly  2042  with the receiving assembly  2010  of the delivery device  2004  can simplify the delivery process. That is, once the delivery device  2004  is properly positioned, the mechanical engagement of the several pieces of the tool  2000  can control the proper position of the implant thereby simplifying and expediting the delivery and implantation process. The user can rely on the position of the delivery device  2004  for placement of the implant thereby minimizing time and/or adjustments to ensure that the implant is properly positioned. 
     Turning again to  FIGS.  136  and  137   , several views of an injector  2102  are shown. The injector  2102  may include features the same or similar to the injectors previously described. In particular, the injector  2102  can include features the same or similar to the injector  1102 . In the present embodiment, the injector seating feature  2119  can include connection features  2043  the same or similar to those described on the necked down portion of the handles of the chisel  2006  and the driver assembly  2042 . In addition, the seating feature  2119  of the injector  2102  can include a slot cavity for positioning around and receiving the malleting anvil on the receiving assembly  2010  of the delivery device  2004 . The plunger  2123  of the injector  2102 , as shown in  FIG.  151   , can include a handle  2125 , a shaft  2127 , and a seal  2129 . The plunger  2123  can be advanced through the injector  2102  to eject bone paste or other materials into and/or around the facet joint. 
     It is noted that when comparing tool  1000  to tool  2000  at least two differences include the handle  2032  on the chisel  2008  and the integration of the internal actuator  2052  with the driver assembly  2042 . With respect to the chisel difference, the tool  2000  can be adapted for a one-step facet joint access process. That is, rather than first advancing the chisel  1006  and then sleeving the delivery device  1004  over the chisel, both the chisel  2008  and the deliver device  2004  can be advanced into the facet joint at the same time. With respect to the driver assembly difference, the tool  2000  can be adapted for a smaller diameter than the tool  1000 . That is, in integrating the driver assembly  2042  with the internal actuator  1052 , one of the concentric tubes, namely the tubular shaft  1055 , has been omitted. Additionally, the implant holding arms  2048  can be adapted to hold the implant from behind rather than from the sides. That is, the arms  2048  can pass within the implant and remain within the width defined by the implant. This allows the driver assembly  2042  to have a smaller size than the driver assembly  1042  and also allows the delivery device  2004  to have a smaller size than the delivery device  1004 . Accordingly, the driver assembly  2042  can have a radius of approximately 1 mm to approximately 5 mm. In a preferred embodiment, the driver assembly can have a radius of approximately 3 mm. Additionally, the delivery device  2004  can have a radius of approximately 1.5 mm to approximately 6 mm. Preferably the delivery device  2004  can have a radius of approximately 4 mm. In one embodiment, the delivery device  2004  can have a radius of approximately 5 mm for a majority of its length and can have a radius of 4 mm near the forks  2012 . For example, as shown in  FIG.  149   , the outer surface of the delivery device  2004  can neck down at or near the alignment hole. This necked down portion can be by way of squaring off the outside surface of the forks such that the outside surface of the forks is not radiused like the outer surface of the shaft portion of the delivery device  2004 . 
     Referring to  FIGS.  152  and  153 A -C, an implant distractor  2050  is shown. The implant distractor  2050  can include features the same as or similar to the features of the implant distractor  850 . For example, the implant distractor  2050  can include a continuous coil-shaped thread feature  2066 . Additionally, the thread feature  2066  may be interrupted by at least one cross-cut  2115  at one or more locations along the threaded feature  2066 . In one embodiment, as shown, a single cross-cut  2115  may be positioned just proximal to the distal end. This cross-cut  2115  may be positioned approximately 180 degrees out of phase from the abrupt proximal end  2113  of the thread feature  866 . Both the cross-cut  2115  and the abrupt proximal end  2113  may provide for interlocking engagement of the implant distractor  2050  with the implant  154 / 854  and thus prevent backing out of the implant distractor  2050 . As shown, the implant distractor  2050  can include a slotted proximal end  2064  adapted to receive a flat screwdriver type distal end of the internal actuator  2052  shown in  FIG.  148   . 
     The implant distractor  2050  can include a generally elongate cylindrical body  2107  adapted to be advanced between the upper and lower members of the implant causing them to distract. The distal tip of the cylindrical body  2107  can be tapered to accommodate initial engagement with the implant and the remaining portion of the cylindrical body  2107  can be generally elongate with parallel extending edges. Accordingly, a relatively uniform outward force can be induced by the implant distractor  2050  as it advances through the implant  2054 . It is noted that other distractors other than those with thread features can be included and can include alternative advancing mechanisms or can be forcibly advanced. 
     Referring now to  FIG.  156   , an implant  2054  is shown. The implant may include features that are the same as or similar to the implants  154  and/or  854  described with respect to  FIGS.  16 - 24    and  FIGS.  117 - 120    respectively. The implant  2054  can be made from a variety of materials including stainless steel, tungsten, titanium, PEEK, and nitinol. Other suitable materials can be used. The material can be a malleable material and the combination of the material properties and the thickness can be adapted to allow the implant to conform to the shaped of the implant distractor and/or the articular surfaces of the facet joint. For example, the thickness of the upper and lower members  2068 ,  2070  can range from approximately 0.05 mm to approximately 2 mm. In a preferred embodiment, the thickness can be approximately 0.38 mm. 
     Referring to  FIGS.  157 - 162   , several perspective views of an implant  2054  are shown. It is noted that the delivery tool has been omitted for clarity and the method/order of insertion of the implant and the distractor may be different from that depicted here. In  FIG.  157   , the implant  2054  is shown prior to insertion into a facet joint. The implant can include upper and lower planar members similar to that described with respect to implants  154  and  854 . The planar members can be generally parallel to one another. As shown in  FIG.  158   , the implant  2054  can be inserted into a facet joint. As further shown in  FIG.  159   , an implant distractor can be advanced between the relatively planar members forcing the members apart and against the opposing surfaces of the facet joint. 
     Referring to  FIGS.  160 A-C , the force of the distractor within the implant  2054  can cause the teeth of the implant to gain purchase in the facet joint surface and can further cause distraction of the joint. The relatively malleable nature of the implant  2054  can cause the implant  2054  to conform to the shape of either the implant distractor or the articular surfaces of the facet joint, or both, while still distracting the joint. 
     In the embodiment shown, the generally elongate implant distractor can be positioned generally centered across the width of the upper and lower members of the implant. Additionally as shown, the teeth of the implant can be positioned along the lateral edges of the implant. In this embodiment, as the implant distractor is advanced into the implant, the spreading force of the implant distractor can force the teeth of the implant into the opposing facet surfaces causing them to gain purchase therein as shown in  FIG.  160 A . The teeth can engage the bone substantially. In some embodiments, the teeth can be completely seated in the facet surfaces such that the upper and/or lower members abut the surface of the facet joint. The thread feature of the implant distractor can also engage the facet surfaces as it protrudes through the slots in the implant. 
     The separation force of the implant distractor can act near the center of the upper and lower members between the teeth of the implant. This spreading force can be counteracted by the naturally resistive force of the articular surfaces of the facet. In this embodiment, this naturally resistive force can act on the engaged teeth of the implant. The concurrent spreading force and opposing resistive force can thus function to form or bend the implant around the axis of the elongate implant distractor forcing it to generally conform to the shape of the implant distractor, as best shown in  FIG.  160 B . This forming can allow the center portion of the upper and lower member to more closely approach the articular surfaces of the facet joint rather than being held off from the articular surface by any remaining height of the teeth. Accordingly, the threaded slots in the upper and lower member can allow the thread feature of the implant distractor to project through and further engage the articular surfaces of the facet. It is also noted that to the extent the articular surface of the facet joint is concave across its lateral width, the forming of the implant can be emphasized. This is because the edges of the articular surface can continue to force the lateral edges of the implant around the implant distractor. 
     In some embodiments, the implant distractor can be generally straight with a tapered tip or it can include a tapered tip transitioning into a relatively barrel-shaped mid section followed by a tapered trailing end. In either case, and as shown best in  FIG.  160 A , the outward forces of the implant distractor in conjunction with the compressive forces of the articular surfaces of the facet can cause the implant to conform to the shape of the implant in this direction also creating an generally elliptically shaped implant. Accordingly, and as shown by review of  FIGS.  160 A and  160 B , the planar members of the implant  2054  can take on a doubly curved shaped corresponding to the shaped of implant and resembling the concave shape of the articular surfaces. 
       FIGS.  161 A and  161 B  show additional views of the implant  2054  reflecting a similar conforming transition between opposed planar members of the implant  2054  in  FIG.  161 A , and opposed doubly curved members of the implant  2054  in  FIG.  161 B . In these views, the facet joint has been omitted for clarity. As can be seen from a review of  FIG.  161 B , the upper member of the implant  2054  can be concave and can form about the longitudinal axis of the elongate distractor. Additionally, as can be seen by viewing the longitudinal seam between the upper and lower member, the upper member and lower member can also form a relatively elliptical shape about an axis perpendicular thereto. 
     It is noted that alternative implant distractors can be used depending on the shape of the implant desired. For example, a broader implant distractor can be provided for broader joints to broaden the longitudinal cross-section of the implant and better distribute the compressive forces. The anterior to posterior profile of the implant distractor can be adjusted to reflect the shape of the articular surfaces of a particular joint thereby allowing the implant to do the same. Implant distractors that provide a relatively uniform expansive pressure to separate the upper and lower members can also be provided to cause the implant to more uniformly conform to the shape of the articular surfaces of a particular joint. These distractors can include fluid type distractors or other relatively uniform pressure devices. 
     Referring to  FIG.  162   , a mechanically tested implant is shown exhibiting the conforming properties described. That is, the implant has conformed under compressive pressure to reflect the shape of the implant distractor and/or the contour of the opposing surfaces of a facet joint. The implant exhibits a formed shaped around the longitudinal axis and an axis transverse thereto. 
     Referring to  FIGS.  163 - 170   , the dimensions of a particular embodiment of the tool are shown.  FIG.  163    includes exemplary dimensions of an implant.  FIG.  164    includes exemplary dimensions of a delivery device.  FIG.  165    includes exemplary dimensions of an implant distractor.  FIG.  166    includes exemplary dimensions of a chisel.  FIG.  167    includes exemplary dimensions of a place holding chisel.  FIG.  168    includes exemplary dimensions of a driver assembly.  FIG.  169    includes exemplary dimensions of a decorticator.  FIG.  170    includes exemplary dimensions of a malleting tool.  FIGS.  163 - 170    reflect dimensions of just one example of an embodiment of a tool. The tool can be constructed with alternative configurations, dimensions, and relationships and is not limited to these particular examples. 
     Referring now to  FIGS.  171 - 174   , an additional embodiment of a chisel  2209  is shown. The chisel  2209  can be adapted to facilitate easier initial access of the facet joint. The chisel  2209  can include features the same or similar to previously disclosed chisels, for example, chisel  2008  and/or chisel  2009 . As shown in  FIG.  171   , the chisel  2209  can include a distal portion  2211  and a proximal portion  2213 . The combined length of the distal portion  2211  and the proximal portion  2213  can form the overall length of the chisel  2209 . The overall length of the chisel  2209  can be the same or similar to the length of the chisel  2009 . As such, when the distal tip of the chisel is in place in a facet joint within, for example, a delivery device  2004 , the distal end of the chisel  2209  can extend out of the distal end of the delivery device  2004  to allow for manipulation of the chisel  2209 . 
     Referring now to  FIG.  172   , a close-up view of the distal portion  2211  of the chisel  2209  is shown. The distal portion  2211  can include a chamfered tip  2230  similar to the previously disclosed chamfered tips. However, the chamfered tip shown includes ridges  2037  on one face of the tip  2230  as shown in  FIG.  172    and not on the opposing face as shown in  FIG.  173   . In some embodiments, ridges  2037  can be included on each face or may be omitted altogether. Where the ridges  2037  are omitted on one or both faces, resistance experienced by a user attempting to access a facet joint with the tip of the chisel  2209  may be minimized. However, the ability to decorticate the facet surfaces may also be reduced. 
     Referring still to  FIG.  172   , the distal portion  2211  of the chisel  2209  can be a generally elongate and cylindrically shaped member with a longitudinal bore  2215  extending there through. The cylindrical cross-section of the distal portion  2211  can have a radius ranging from approximately 1 mm to approximately 6 mm. In other embodiments, the radius can range from approximately 3 mm to approximately 5 mm. In one embodiment, the radius can be approximately 4 mm. The bore  2215  can be sized and adapted to receive and pass through a needle. In some embodiments, the needle can be approximately a 12 GA to approximately a 28 GA needle. In other embodiments, the needle can be a gauge somewhere in between 12 to 28 or a gauge beyond 12 to 28. In one embodiment, the needle may be a 22 GA needle. 
     The bore  2215  can be generally centered in the circular cross-section of the distal portion  2211  and can extend from the transition between the proximal portion  2213  and the distal portion  2211  to the distal tip of the chisel  2209 . The bore can extend through the chamfered tip  2230  creating a notch  2217  in the chamfered tip  2230  at its distal edge. The bore  2215  can be exposed to the environment surrounding the chisel  2209  via a plurality of holes  2219  and/or a slot  2221 . 
     The distal portion  2211  can have a length adapted to accommodate standard length needles. That is, the distal portion  2211  can have a length adapted to accommodate a 5″, an 8″, or a 10″ standard length surgical needle for example. In these embodiments, the distal portion  2211  of the chisel  2209  can have a length such that when the needle is inserted into the bore  2215  from the proximal end and the needle hub provided on the needle abuts the transition between the distal portion  2211  and the proximal portion  2213 , the distal tip of the needle can extend between approximately, 5 mm to approximately 35 mm beyond the distal tip of the chisel  2209 . In some embodiments, the length of the distal portion  2211  is such that a standard length needle can extend between approximately 15 mm to approximately 25 mm beyond the distal tip of the chisel  2209 . 
     Referring now to  FIG.  174   , the proximal portion  2213  is shown. The proximal portion  2213  of the chisel  2209  can extend from the distal portion  2211  and be adapted for manipulating the distal tip of the chisel  2209 . The proximal portion  2213  can have a length adapted to extend from a delivery device  2004  when a delivery device is inserted over the chisel  2209 . In the present embodiment, the proximal portion  2213  includes a semi-circular cross-section and is generally solid. The cross-sectional shape can define an arcuate surface and a generally flat surface of the proximal portion  2213 . The arcuate portion can be a continuation of an arcuate ½ of the distal portion  2211  and the flat portion can extend from the transition at approximately the mid-depth of the distal portion  2211  proximally to the proximal end of the chisel  2209 . The proximal portion  2213  can be hollow and/or can include alternatively shaped cross-sections. As shown, the proximal portion  2213 , near the transition to the distal portion  2211 , can include an entry feature  2223  adapted to receive a needle and facilitate advancing the needle into and through the bore  2215  of the distal portion. The entry feature  2223  can be centered on the proximal portion  2213  in alignment with the bore  2215  and can be in the form of a groove or trough in the flat surface of the proximal portion  2213 . The entry feature  2223  can extend from the transition proximally away from the transition and along the flat surface. 
     The above description has included some references to use to allow for a better understanding of the structure. Below is a more detailed discussion of that use including the devices and techniques for distracting and retaining a facet joint in a distracted and forwardly translated condition. The implantation procedure may be performed under conscious sedation in order to obtain intra-operative patient symptom feedback. 
     The joint, which can be difficult to access, may be accessed pursuant, for example, to a method and apparatus disclosed in U.S. Non-provisional application Ser. No. 61/350,609, filed Jan. 8, 2009, which is commonly owned with the present application and hereby incorporated by reference. Pursuant to the disclosure in that application, the access system may include one or more cannulas made of steel, titanium, or plastic. The initial facet joint access cannula may have a sharp spatula tip on the distal end. The spatula tip may have a flat configuration to enable access into the flat facet joint. Once the spatula tip achieves access into the flatly oriented facet joint, subsequent stylets and working instruments may be passed down this access channel to complete a distraction procedure. Alternatively the dilation set  1200  may be used. Alternatively, one or a plurality of the chisel and delivery devices described above may be used to access the joint. The distraction procedure may then begin. 
     More particularly, initially, an incision may be made in the patients back. Tools known in the art may be used to create this incision and the dilator set  1200  may be used to open an access path through the tissues of the back as described above. 
     In the case of a tool  1000 , once an access path is created, the chisel  1008  described above may be advanced through the incision and the distal tip  1030  may be positioned adjacent the target facet joint. It is noted that chisel  1008  with an interior lumen may allow for visualization to be provided by including a scope within the chisel  1008 . Additionally, an incision in the facet joint capsule may be made prior to beginning the procedure, and thus prior to insertion of the chisel  1008 . Once the distal tip of the chisel  1008  is properly positioned adjacent the facet joint, the chisel  1008  may be inserted into the facet joint. The chisel  1008  may be used to decorticate the articular surfaces of the facet joint by manipulating the chisel  1008  within the joint. This may include tapping the chisel with a device such as a hammer, mallet, or other instrument to advance the distal tip  1030  of the chisel  1008  and may also include moving the proximal end of the chisel laterally from side to side, up and down, or rotationally, to decorticate the joint. The chisel  1008  may then be tapped into place anteriorly such that it extends substantially through the joint. Fluoroscopy from one or more directions may be used to verify the location of the chisel. 
     The delivery device  1004  may be slidably advanced over the chisel  1008  and the forks  1012  of the delivery device  1004  may be advanced into the facet joint. Additional fluoroscopy from one or more directions may be used to verify proper placement of the delivery device  1004  and forks  1012 . The chisel  1008  may be removed. 
     An implant may be placed in the driver assembly  1042  and the implant and driver assembly  1042  may be slidably advanced through the delivery device  1004 . The forks  1012  of the delivery device  1004  may be holding the facet joint slightly distracted. As such, the implant, in its relatively flat and parallel position, may slide relatively easily into the facet joint. To the extent that it does not, the proximal end of the driver assembly  1042  may be tapped to properly advance and position the implant. 
     The button on the handle  1053  of the internal actuator  1052  may be pressed to expose the engagement feature  1059  at the distal end of the internal rod  1057  of the internal actuator  1052  and the implant distractor may be placed therein. The button may be released causing at least the proximal end of the implant distractor and the engagement feature  1059  to be retracted within the longitudinal shaft  1055  of the internal actuator  1052  thereby causing a clamping force on the engagement feature  1059  and securing the implant distractor. 
     The internal actuator  1052  may then be inserted into the proximal end of the driver assembly  1042  and advanced to a point just proximal to the implant. Once properly positioned, the handle  1053  may be rotated or otherwise actuated to advance the implant distractor into the implant thereby distracting implant and the facet joint. 
     The button on the handle  1053  may be pressed again to expose the engagement feature  1059  at the distal end of the internal rod  1057  from the longitudinal shaft  1055  thereby reducing the clamping force of the engagement feature on the implant distractor and allowing for removal of the internal acuator, while the implant distractor is threadably engaged with the implant. Additionally, the distraction of the implant may cause the upper and lower members of the implant to clear the engagement features  1058  of the holder arms  1048  thus allowing the driver assembly  1042  to be freely removed from the delivery device  1004  leaving the implant and the implant distractor behind. 
     The injector  1102  may be advanced through the delivery device  1004  and positioned adjacent to the facet joint. The handle  1025  of the plunger  1023  may be depressed thus advancing the plunger  1023  and ejecting the bone paste or other anchoring material. The injector  1102  may be removed. The delivery device  1004  may also be removed and the incision may be closed. The above procedure may be conducted to treat one or both contralateral facet joints. 
     An implant may additionally or alternatively be delivered with the tool  2000 . As discussed with respect the chisel  2008 , the delivery device  2004  and the chisel  2008  can be inserted in a one step process. That is, after the incision is made and the tissues of the back are properly dilated, the chisel  2008  and delivery device  2004  can be advanced into the facet joint. Once properly positioned, the chisel  2008  can be removed from the receiving assembly  2010  by prying it free with the malleting tool  2001  or using available push buttons. The removal of the chisel  2008  can prepare the tool  2000  for insertion of the driver assembly  2042 . Where contralateral facet joints are being treated, the placing holding chisel  2009  can be placed down the shaft of the delivery device  2004  and the delivery device  2004  can be removed. The delivery device  2004  and the chisel  2008  can then be inserted in the contralateral joint and once properly positioned, the chisel  2008  can be removed to prepare for insertion of the driver assembly  2042 . 
     In some embodiments, the chisel  2209  can be used to initially establish the location of the joint and the proper trajectory of the tool. In this embodiment, the chisel  2209  can be inserted toward a facet joint and be advanced to the lateral mass of the facet joint. This can be done prior to insertion of the tool as mentioned above. A needle can be inserted through the chisel  2209  and extended out the end of the chisel  2209 . The surrounding lateral mass can be probed with the needle to determine the location of the facet joint and the position and trajectory of the chisel  2209  can be adjusted until the needle enters the facet joint. Additionally, using lateral fluoroscopy, the needle can be used to determine if the trajectory of the entry is aligned with the slope of the facet joint. That is, if the needle enters the joint, but bends as it continues into and across the joint, the trajectory may not be aligned with the slope of the joint. The chisel trajectory can thus be adjusted, which may include adjusting the bodily entry point. 
     When the proper trajectory and location are established, the chisel  2209  can be advanced over the needle and into the joint. To transition back to the tool  2000 , a series of dilation tubes can be used. That is, as mentioned, in one embodiment, the chisel  2209  can have a cross-section radius of 4 mm. A 5 mm radius tube can be advanced over the chisel  2209  and a 6 mm radius tube can be advanced over the 5 mm radius tube and the 5 mm radius tube can then be removed, leaving the 6 mm radius tube sleevably positioned over the 4 mm radius chisel  2209 . Dilations tubes similar to those described with respect to  FIGS.  129 - 135    can be used. 
     The one-step tool  2000  can thus be used by removing the chisel  2008  from the delivery device  2004  and the delivery device  2004  can be sleevably advanced over the chisel  2209  and within the 6 mm radius dilation tube and the forks  2012  can be advanced into the facet joint. The 6 mm radius dilation tube can be removed and the chisel  2209  can also be removed. To the extent decortication is desired, the chisel  2008  or  2009  can be inserted through the delivery device  2004  and the joint can be decorticated. Where contralateral joints are being addressed, the place holding chisel  2009  can be inserted in the joint to maintain the access to the joint without occluding fluoroscopic view of the contralateral joint. 
     An implant, for example implant  2054 , can be positioned on the distal end of the driver assembly  2042  and the U-shaped receiving feature slots on the lateral sides of the implant can be positioned over the engagement features  2058 . It is noted that, when in position, the width of the driver assembly  2042  can be the same or similar to the width of the implant. This is in contrast to that, which is depicted in  FIG.  12   , for example, with driver assembly  142 . The upper and lower surfaces of the implant can be biased toward a parallel position and, as such, when placed over the distal end of the driver assembly  2042 , may provide a slight clamping force on the distal end of the driver assembly  2042 . In addition, an implant distractor such as, for example distractor  2050 , can be advanced slightly into the proximal end of the implant causing the continuous thread feature  2066  to engage the threaded slots of the implant and further secure the implant to the driver assembly. Moreover, this initial starting of the implant distractor  2050  in the implant  2054  can help avoid mis-threading of the distractor  2050 . In one embodiment, the implant distractor can be advance, for example, 2 turns into the implant. 
     Having placed the implant on the distal end of the driver assembly  2042 , the driver assembly  2042  and the implant can be advanced through the delivery device  2004  and the implant can be positioned in the facet joint. Rotation of the handle  2053  can cause rotation of the internal rod  2057  thereby causing rotation of the implant distractor  2050 . Accordingly, the thread feature  2066  can cause the implant distractor  2050  to advance relative to the implant  2054  thereby distracting the implant  2054  and, in turn, also distracting the facet joint. It is noted that distraction of the implant  2054  can cause the implant to be free from the engagement features  2058  on the distal end of the driver assembly  2042  and as such, once distracted, the driver assembly  2042  can be removed. 
     In another embodiment, a tool  3000  may include some or all of the elements described with respect to tool  1000 . However, rather than combining the driver assembly  1042  and the internal actuator  1052 , as with tool  2000 , in this embodiment, the driver assembly  1042  may be omitted. In this embodiment of a tool  3000 , delivery of the implant may be conducted with the internal actuator  1052 . That is, the implant distractor may be initially partially engaged with or “started” in the implant sufficiently to hold the two together. This engagement may be due to the implant being biased to keep the upper and lower members in a parallel position thus creating a threaded and frictional resistance to separation of the implant and the implant distractor. Additionally or alternatively, this engagement may be due to engagement of a cross-cut thread on the implant distractor being engaged with a truncated threaded slot of the implant. Once the implant distractor is started in the implant, the implant distractor may be engaged with the engagement feature on the internal actuator  1052  thus stringing the internal actuator  1052 , the implant distractor, and the implant together. The internal actuator  1052  together with the implant distractor and the implant may then be advanced down the tubular shaft  1014  of the delivery device  1004  in lieu of the driver assembly  1042 . 
     In this embodiment, the omission of the driver assembly  1042  may allow for smaller sized shafts of several devices similar to tool  2000 . In one embodiment, the outer radius of the tubular shaft  1014  of the delivery device  1004  may be approximately 4 mm and the outer radius of the decorticator may be approximately 5 mm. 
     In still another embodiment, the several handles/seating features (e.g.,  1044 ,  2044 ,  1119 ) may include a slot opening on their distal end for use in separating the handles from the receiving assembly  1010 . That is, when the handles are engaged with the receiving assembly and the projections are seated in the seating cavities, the frictional/suctional fit of the handles in the receiving assembly may be difficult to separate. Accordingly, a slot opening on the distal end of the handles may be provided, which may provide for accessing the joint between the handles and the receiving assembly with a separation device which may assist in working the elements apart via prying, scissor action, or other known methods. Alternatively or additionally, the frictional engagement of the several handles in the receiving assembly may be reduced. 
     The delivery system disclosed herein is advantageous for at least the following reasons. First, the system facilitates delivery of an implant to a facet joint via a minimally invasive or percutaneous procedure, reducing the risk, surgical time and recovery time associated with the implantation of the implant in the facet joint. Accordingly, many of the dimensional characteristics associated with the delivery system, its components, and the implant are advantageous in that they facilitate or make possible the minimally invasive or percutaneous procedures described herein. Second, the system facilitates the implant being delivered while the patient is capable of providing verbal feedback as to the impact of the implant relative to symptoms being felt by the patient. 
     Referring now to  FIGS.  175 - 177   , an implant is shown positioned between vertebral bodies of the lumbar spine and adapted for an interbody fusion. While the majority of this application has addressed the use of implants placed in one or more facet joints, the implants and delivery devices herein described can also be used in other joints of the spine. As shown, for example, the implant can be used where a disc has deteriorated and/or been removed from a spinal joint between vertebral bodies. In the case of a discectomy type procedure, the implants can be used after the disc has been removed to secure two adjacent vertebral bodies and maintain their separation. The currently described delivery tools and implants are not limited to use in the cervical or lumbar spine and further are not limited to facet joints or joints between vertebral bodies. 
     Discectomy type procedures are often performed from one of three different access points. In one procedure, the spinal column is approached from the posterior. In another procedure, the spinal column is approached anteriorly and in another, from the lateral side of the patient. Referring particularly to  FIG.  175   , an implant procedure is shown where a posterior approach has been used. That is, where the discectomy is performed from the posterior, the implant can be delivered from the posterior as well. Referring particularly to  FIG.  176   , an implant procedure is shown where a lateral approach has been used and  FIG.  177   , shows the implant where an anterior approach has been used. It is noted that the implant can be delivered from any position and the delivery approach does not have to be consistent with the discectomy approach. That is, for example, if the discectomy is performed anteriorly, the implant delivery may be done anteriorly as well, but could also be performed posteriorly or laterally. However, it may be advantageous to use the same delivery approach as the discectomy for purposes of minimizing incisions. 
     In any of the above approaches, the procedure to place an implant between vertebral bodies can be the same or similar to the procedure to place the implants in a facet joint. For example, the chisel  2008  and delivery device  2004  of tool  2000 , for example, can be advanced into the joint between vertebral bodies. As shown in  FIGS.  175 - 177   , this can be completed from one of several directions. The teeth of the chisel  2008  can be used to decorticate the joint as desired. Once properly positioned and decorticated, the chisel  2008  can be removed from the receiving assembly  2010  by prying it free with the malleting tool  2001  or using available push buttons. The removal of the chisel  2008  can prepare the tool  2000  for insertion of the driver assembly  2042 . Fluorscopy can be used to verify proper placement of the delivery device  2004  to ensure proper placement of an implant. 
     An implant, for example implant  2054 , can be positioned on the distal end of the driver assembly  2042 . The U-shaped receiving feature slots on the lateral sides of the implant  2054  can be positioned over the engagement features  2058  and an implant distractor  2050  can be advanced slightly into the proximal end of the implant  2054 , for example, 2 turns into the implant. The driver assembly  2042  and the implant  2054  can be advanced through the delivery device  2004  and the implant  2054  can be positioned in the joint between the vertebral bodies. Rotation of the handle  2053  can cause rotation of the internal rod  2057  thereby causing rotation of the implant distractor  2050 . Accordingly, the thread feature  2066  can cause the implant distractor  2050  to advance relative to the implant  2054  thereby distracting the implant  2054  and, in turn, also distracting the joint between the vertebral bodies. It is noted that distraction of the implant  2054  can cause the implant to be free from the engagement features  2058  on the distal end of the driver assembly  2042  and as such, once distracted, the driver assembly  2042  can be removed. A similar procedure can be performed to place a second implant  2054 . While this procedure has been described with regard to tool  2000  and implant  2054 , any of the described tools and implants described can be used. 
     Some additional methods of use are described below with reference to  FIGS.  178 - 185   . In each of the shown methods, any combination of the steps shown or portion of the steps can be included. Additionally, the order of the steps can be rearranged and is not limited the orders of the boxes or label numbers shown. 
     Referring to  FIG.  178   , in one embodiment, a method of distracting a facet joint of the spine can include inserting a delivery device to access the facet joint of a patient ( 4000 ), inserting a driver assembly holding an implant into the delivery device ( 4002 ), and actuating the driver assembly thereby distracting the implant ( 4006 ). Inserting the delivery device can include inserting a chisel through the delivery device and tapping on the proximal end of the chisel to advance the chisel and the delivery device into the facet joint. Actuating the driver assembly can include turning a distractor knob on the driver assembly thereby rotating an internal actuator and advancing an implant distractor. The method can also include inserting an injector in the delivery device and delivering a bone paste to the implantation site. ( 4008 ) 
     Referring to  FIG.  179   , in one embodiment, a method of distracting a facet joint of the spine can include dilating a path to a facet joint using a dilator set ( 4010 ), inserting a chisel into the facet joint ( 4012 ), advancing a delivery device over the chisel and inserting forks of the delivery device into the facet joint ( 4014 ), removing the chisel from the joint ( 4016 ), inserting a driver assembly with an implant into the delivery device, seating the driver assembly in the delivery device thereby positioning the implant between the forks of the delivery device and in the facet joint ( 4018 ), inserting an internal actuator into the driver assembly and advancing an implant distractor into the implant thereby distracting the implant ( 4020 ), actuating a button on the internal actuator thereby releasing a grip on the implant distractor and removing the internal actuator and the driver assembly ( 4022 ), and inserting an injector and injecting a flowable material into or around the facet joint ( 4024 ). In some embodiments, advancing the implant distractor can include turning a handle on the internal actuator thereby rotating an internal rod and threadably advancing an implant distractor. 
     Referring to  FIG.  180   , a method of distracting a facet joint of the spine can include inserting a chisel into a facet joint to provide initial distraction and decorticate the surface of the joint ( 4026 ), inserting a delivery device over the chisel to maintain the initial distraction ( 4028 ), inserting an implant through the delivery device and into the joint, the implant having teeth adapted to engage the surfaces of the joint ( 4030 ), distracting the implant by advancing an implant distractor, the implant distractor having a coil-shaped thread feature for engaging threaded slots of the implant, the implant distractor further having cross-cut threads for engaging truncated threaded slots on the implant, wherein, advancing the implant distractor includes causing the cross-cut threads to engage the truncated threaded slots and prevent backing out of the implant ( 4032 ), and releasing the implant distractor and removing the delivery device thereby leaving the implant and the implant distractor in place in the joint ( 4034 ). 
     Referring to  FIG.  181    a method of distracting a facet joint of the spine can include inserting a delivery device into a facet joint ( 4036 ), inserting an implant through the delivery device and into the joint ( 4038 ), and distracting the implant by advancing an implant distractor ( 4040 ). 
     Referring to  FIG.  182   , a method of distracting a facet joint of the spine can include partially engaging an implant distractor with an implant and engaging the implant distractor with an internal actuator to form an assembly ( 4042 ), inserting the implant portion of the assembly into the facet joint ( 4044 ), and distracting the facet joint ( 4046 ). In some embodiments, distracting the facet joint can include actuating the internal actuator which advances the implant distractor. 
     Referring to  FIG.  183   , a method of distracting a facet joint and a contralateral facet joint of a spine can include inserting a delivery device and chisel assembly into the facet joint ( 4048 ), removing the chisel from the assembly and replacing the chisel with a place holding chisel ( 4050 ), removing the delivery device from the facet joint ( 4052 ), inserting the delivery device and chisel assembly into the contralateral facet joint ( 4054 ), removing the chisel from the assembly ( 4056 ), placing and distracting a first implant in the contralateral facet joint ( 4058 ), removing the delivery device from the contralateral facet joint ( 4060 ), placing the delivery device back in the facet joint via the place holding chisel ( 4062 ); and placing and distracting a second implant in the facet joint ( 4064 ). In some embodiments, the place holding chisel can be a radiolucent chisel. The method can also include performing lateral fluoroscopy to determine proper placement of the first implant ( 4066 ). 
     Referring to  FIG.  184   , a method of distracting a facet joint of the spine can include inserting a delivery device and chisel assembly into the facet joint to provide initial distraction and decorticate the surface of the joint ( 4068 ), removing the chisel assembly from the delivery device ( 4070 ), inserting a driver assembly through the delivery device, the driver assembly holding an implant and further comprising an implant distractor adapted to distract the implant ( 4072 ), distracting the implant ( 4074 ), and removing the driver assembly and the delivery device ( 4076 ). The method can also include positioning the delivery device and chisel assembly by selectively malleting a proximal end thereof ( 4078 ). The method can also include selectively malleting a proximal end of the driver assembly ( 4080 ) and can further include positioning a decorticator on the delivery device from the lateral side of the device ( 4082 ). Still further, the method can include advancing the decorticator along the length of the driver assembly, positioning a malleting tool against the proximal end of the decorticator, and malleting the malleting tool to forcibly advance the decorticator and decorticate the lateral mass of the facet joint ( 4084 ). The method can also include retracting, rotating, and re-advancing the decorticator in a new position and malleting the malleting tool to decorticate a different location ( 4086 ). In addition, the method can include obtaining intra-operative patient symptom feedback ( 4088 ). 
     Referring to  FIG.  185   , a method of performing an interbody fusion can include inserting a delivery device and chisel assembly into a joint between vertebral bodies of the spine ( 4090 ), removing the chisel assembly from the delivery device ( 4092 ), inserting a driver assembly through the delivery device, the driver assembly holding an implant and further comprising an implant distractor adapted to distract the implant ( 4094 ), distracting the implant ( 4096 ), and removing the driver assembly and the delivery device ( 4098 ). The method can also include repeating the steps to place a second implant in the joint ( 4100 ). 
     Although the present invention has been described with a certain degree of particularity, it is understood the disclosure has been made by way of example, and changes in detail or structure may be made without departing from the spirit of the invention as defined in the appended claims.