Abstract:
The disclosure relates to devices and methods for implantation of an orthopedic device between skeletal segments using limited surgical dissection. The implanted devices are used to adjust and maintain the spatial relationship(s) of adjacent bones. Depending on the implant design, the motion between the skeletal segments may be increased, limited, modified, or completely immobilized.

Description:
REFERENCE TO PRIORITY DOCUMENT  
       [0001]     This application claims priority of co-pending U.S. Provisional Patent Application Ser. No. 60/631,213, filed Nov. 24, 2004 and co-pending U.S. Provisional Patent Application Ser. No. 60/713,235, filed Aug. 31, 2005. Priority of the aforementioned filing dates is hereby claimed, and the disclosures of the Provisional Patent Applications are hereby incorporated by reference in their entirety. 
     
    
     BACKGROUND  
       [0002]     The disclosure relates to devices and methods for implantation of an orthopedic device between skeletal segments using limited surgical dissection. The implanted devices are used to adjust and maintain the spatial relationship(s) of adjacent bones. Depending on the implant design, the motion between the skeletal segments may be increased, limited, modified, or completely immobilized.  
         [0003]     Progressive constriction of the central canal within the spinal column is a predictable consequence of aging. As the spinal canal narrows, the nerve elements that reside within it become progressively more crowded. Eventually, the canal dimensions become sufficiently small so as to significantly compress the nerve elements and produce pain, weakness, sensory changes, clumsiness and other manifestation of nervous system dysfunction.  
         [0004]     Constriction of the canal within the lumbar spine is termed lumbar stenosis. This condition is very common in the elderly and causes a significant proportion of the low back pain, lower extremity pain, lower extremity weakness, limitation of mobility and the high disability rates that afflict this age group. The traditional treatment for this condition has been the surgical removal of the bone and ligamentous structures that constrict the spinal canal. Despite advances in surgical technique, spinal decompression surgery can be an extensive operation with risks of complication from the actual surgical procedure and the general anesthetic that is required to perform it. Since many of these elderly patients are in frail health, the risk of developing significant peri-operative medical problems remains high. In addition, the traditional treatment of surgical resection of spinal structures may relieve the neural compression but lead to spinal instability in a substantial minority of patients. That is, removal of the spinal elements that compress the nerves may cause the spinal elements themselves to move in an abnormal fashion relative to one another and produce pain. Should it develop, instability would require additional and even more extensive surgery in order to re-establish spinal stability. Because of these and other issues, elderly patients with lumbar stenosis must often choose between living the remaining years in significant pain or enduring the potential life-threatening complications of open spinal decompression surgery.  
         [0005]     Recently, lumbar stenosis has been treated by the distraction—instead of resection—of those tissues that compress the spinal canal. In this approach, an implantable device is placed between the spinous processes of the vertebral bodies at the stenotic level in order to limit the extent of bone contact during spinal extension. Since encroachment upon the nerve elements occurs most commonly and severely in extension, this treatment strategy produces an effective increase in the size of the spinal canal by limiting the amount of spinal extension. In effect, distraction of the spinous processes changes the local bony anatomy and decompresses the nerves by placing the distracted spinal segment into slight flexion.  
         [0006]     A number of devices that utilize this strategy have been disclosed. U.S. Pat. Nos. 6,451,020; 6,695,842; 5,609,634; 5,645,599; 6,451,019; 6,761,720; 6,332,882; 6,419,676; 6,514,256; 6,699,246 and other illustrate various spinous process distractors. Unfortunately, the placement of each device requires exposure of the spinous processes and the posterior aspect of the spinal column. Thus, these operations still present a significant risk of peri-operative complications in this frail patient population.  
         [0007]     It would be desirable to design an improved method for the placement of an orthopedic device between the spinous processes of adjacent spinal segments. A workable method of percutaneous delivery would reduce the surgical risks of these procedures and significantly increase the usefulness of these spinous process distractors. This application discloses a device for the percutaneous placement of inter-spinous process implants. The method of use provides a reliable approach that maximizes the likelihood of optimal device placement and obviates the need for open surgery.  
       SUMMARY  
       [0008]     Disclosed are devices and methods that can accurately place an orthopedic device between adjacent spinous processes. The devices and methods employs a percutaneous approach and constitutes the least invasive method of delivery system yet devised. Also disclosed are various instruments for implant placement and the implant itself.  
         [0009]     Pursuant to a procedure, a patient is placed on his side or in the prone position. The hips and knees are flexed and the procedure is performed under x-ray guidance. The level of interest is identified radiographically and bone screws are percutaneously inserted into the spinous processes of the upper and lower vertebras of the stenotic level. A distractor is placed onto the two screws and a needle is placed through the distractor platform and guided into the space between the spinous processes under X-ray guidance. The tip of the needle is guided into the exact position where the implant needs to be placed. The needle is marked so that the distance from the needle tip to the center of rotation of the insertion device (discussed below) can be measured. The platform is then immobilized relative to the rest of the distractor and the spinous processes of the stenotic level are gently distracted. In order to gauge the extent of distraction and better standardize the procedure, a measure of the force of distraction is displayed by the distraction device. The localizing needle is removed.  
         [0010]     A curvilinear device is attached to the platform. The device has a guide arm that rotates about a central point so as to form an arc. Since the distance from the guide arm&#39;s center of rotation to the tip of the localizing needle is known, a guide arm of radius equal to that distance will necessarily form an arc that contains the needle point on its circumference. A trocar with a knife-like tip is placed through the central channel in order to divide tissue before the advancing guide arm. The guide arm is them rotated through the skin and underlying tissue until the distal end of the guide arm abuts the side of the ligament between the spinous processes at the stenotic level. Using this method, a curvilinear path is created to the point marked by the needle tip in a completely percutaneous manner and without any open surgical tissue dissection.  
         [0011]     The trocar is removed from the guide arm&#39;s central canal. The central canal is then used to deliver the implant to the desired point between the spinous processes. Alternatively, a solid guide arm may be used with the implant attached to the tip.  
         [0012]     The placement system described herein provides an easy and reliable way of placing an orthopedic device within the inter-spinous ligament. Using this method, the implant can be placed rapidly, precisely, with a few small skin incisions and the absolute minimum amount of tissue dissection. It permits minimally invasive device placement using only local anesthesia into those afflicted patients who are least able to withstand the stress of open surgical intervention.  
         [0013]     In one aspect, there is disclosed a distractor instrument, comprising: a first distractor member that engages at a distal end to a first skeletal segment; a second distractor member that engages at a distal to a second skeletal segment; a distractor device mounted to proximal ends of the first and second distractor members; and a distraction actuator attached to the distractor device, wherein the distraction actuator is actuated to apply a distraction force to the first and second distractor members to distract the first and second skeletal segments relative to one another.  
         [0014]     In another aspect, there is disclosed a distractor instrument, comprising first and second distraction members that each engage a respective skeletal segment, wherein the distraction members can be distracted to cause distraction of the skeletal segments.  
         [0015]     In another aspect, there is disclosed a method of distracting a pair of spinous processes, comprising using one or more distractor elements to engage the spinous processes to apply a distraction force to the spinous processes.  
         [0016]     In another aspect, there is disclosed a minimally-invasive surgical procedure, comprising localizing a surgical point of interest using a localizing needle that points to the point of interest; and placing an implant at the point of interest using the localizing needle as a guide.  
         [0017]     In another aspect, there is disclosed a minimally-invasive surgical procedure, comprising localizing a surgical point of interest using an x-ray to identify the point of interest; relating the point of interest to a delivery apparatus; and delivering an implant to the point of interest using an inserter device that pivots about a central axis such that the inserter device travels along a curvilinear path that contains the localized point of interest.  
         [0018]     In another aspect, there is disclosed a skeletal implant holder, comprising a hand-operated handle assembly; and a holder assembly attached to the handle assembly. The holder assembly is configured to be removably attached to an implant, wherein the handle assembly can be actuated to secure the implant to the holder assembly and to detach the implant from the holder assembly, and wherein the holder assembly is configured to apply a first force to the implant in a first direction and a second force to the implant in a second direction opposite the first direction when the handle assembly is actuated.  
         [0019]     In another aspect, there is disclosed an implant for implanting between a pair of skeletal segments, comprising a first segment; at least one wing attached to the first segment, the wing movable between a collapsed configuration and an expanded configuration wherein the wing can engage a skeletal segment as an anchor when in the expanded configuration; and a second segment removably attached to the first segment, wherein the second segment can be detached from the first segment to disengage the wing from the skeletal segment.  
         [0020]     These and other features will become more apparent from the following description and the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]      FIG. 1  shows a perspective, assembled view of a distractor device  100  for implanting an orthopedic device between skeletal segments, such as between a first vertebral body V 1  and a second vertebral body V 2 .  
         [0022]      FIG. 2A  shows a perspective view of the device with an insertion device detached.  
         [0023]      FIG. 2B  shows an exploded view of a platform of the device.  
         [0024]      FIG. 3  shows a perspective view of the device with the platform removed.  
         [0025]      FIG. 4  shows a cross-sectional view of sheaths with screws positioned therein.  
         [0026]      FIG. 5  shows an enlarged, cross-sectional view of the upper region of a sheath with a turn screw and a distraction screw a mounted therein.  
         [0027]      FIG. 6  shows a perspective view of the device with a localizing needle coupled thereto.  
         [0028]      FIG. 7  shows a perspective view of the device with a locking instrument coupled to the platform for locking and unlocking the localizing needle.  
         [0029]      FIG. 8  shows a cross-sectional view of the locking instrument attached to the platform.  
         [0030]      FIG. 9  shows a partial exploded view of the platform and shows an exemplary mechanism for effectuating distraction.  
         [0031]      FIG. 10  shows a partial cross-sectional view of the platform in an assembled state.  
         [0032]      FIG. 11  shows an enlarged cross-sectional view of the platform in the region of a force pointer that provides a measure of distraction force provided to vertebral bodies.  
         [0033]      FIG. 12  shows an enlarged view of the pointer and corresponding markings on the platform.  
         [0034]      FIG. 13  shows an enlarged view of the locking mechanism and localizing needle.  
         [0035]      FIG. 14  shows the platform with the locking mechanism and localizing needle coupled thereto.  
         [0036]      FIG. 15A  shows the device with the platform positioned before it had been moved by a turn screw.  
         [0037]      FIG. 15B  shows the platform after movement.  
         [0038]      FIG. 16  is a perspective view of the device showing how the insertion device is pivotably attached to the platform.  
         [0039]      FIGS. 17A and 17B  show enlarged views of the attachment member of the insertion device being lowered onto the attachment screw of the platform.  
         [0040]      FIG. 18  shows a cross-sectional view of the attachment member attached to the attachment screw.  
         [0041]      FIG. 19  shows the device including the pivotably mounted insertion device attached to a pair of vertebral bodies.  
         [0042]      FIGS. 20-22  sequentially illustrate how the insertion device swings toward the target location where the implant is to be positioned.  
         [0043]      FIG. 23  shows the device with a trocar member removed.  
         [0044]      FIGS. 24A, 24B , and  24 C show an exemplary sizing device for determining the appropriate size of an implant.  
         [0045]      FIGS. 25 and 26  shows an implant holder device that can be used to hold an implant and install the implant via the internal shaft in the installer device.  
         [0046]      FIGS. 27A and 27B  show the implant with extendable wings in an undeployed ( FIG. 27A ) and a deployed state ( FIG. 27B ).  
         [0047]      FIG. 28  shows an enlarged view of a portion of the implant coupled to the holder device.  
         [0048]      FIG. 29  shows a cross-sectional view of the implant attached to the holder.  
         [0049]      FIG. 30  shows a close-up view of the implant attached to the holder.  
         [0050]      FIG. 31  shows the implant locked onto the holder with a handle in a locked position.  
         [0051]      FIG. 32  shows a close-up, cross-sectional view of the implant end of the holder.  
         [0052]      FIG. 33  shows the holder and attached implant just prior to insertion into the internal shaft of the curved portion.  
         [0053]      FIG. 34  shows the device with the holder and implant in a ready-to-deploy state.  
         [0054]      FIG. 35  shows the device with the holder and implant in a deployed state.  
         [0055]      FIG. 36  shows a cross-sectional view of the deployed holder and implant.  
         [0056]      FIG. 37  shows a close-up view of the implant coupled to the holder.  
         [0057]      FIG. 38  shows the implant deployed between the vertebral bodies and the holder removed from the device.  
         [0058]      FIG. 39  shows the implant deployed between the vertebral bodies after the inserter device has been rotated out of the soft tissue and the device and distraction screws have been removed.  
         [0059]      FIG. 40  shows how a screw may be removed and the implant disassembled.  
         [0060]      FIG. 41  shows another embodiment of a device with a swinging or pivoting installer device.  
         [0061]      FIG. 42  shows a mounting post in an exploded state.  
         [0062]      FIG. 43  shows the mounting post attached to a vertebral body.  
         [0063]      FIG. 44  shows a free end of the post a positioned along a line L parallel to the inter-spinous space.  
         [0064]      FIG. 45  shows the insertion device prior to attachment to the post.  
         [0065]      FIG. 46  shows the insertion device attached to the post.  
         [0066]      FIG. 47  shows an exploded view of an attachment device for attaching the insertion device to the post.  
         [0067]      FIG. 48  shows a cross-sectional view of the attachment device.  
         [0068]      FIG. 49  shows a side view of a plunger that couples into the insertion device.  
         [0069]      FIG. 50  shows a side view of the device with the plunger positioned inside the curved portion of the insertion device.  
         [0070]      FIG. 51  shows a perspective view of the insertion device with a tapered end contacting the lateral side of the inter-spinous space.  
         [0071]      FIG. 52  shows a perspective view of another embodiment of a distractor device coupled to vertebral bodies.  
         [0072]      FIG. 53  shows another perspective view of the distractor device of  FIG. 52 . 
     
    
     DETAILED DESCRIPTION  
       [0073]     Disclosed are methods and devices for implanting a device (such as an orthopedic device) between skeletal segments (such as vertebrae), using limited surgical dissection. The implanted devices are used to adjust and maintain the spatial relationship(s) of adjacent bones.  
         [0074]      FIG. 1  shows a perspective, assembled view of a distractor device  100  for implanting an orthopedic device between skeletal segments, such as between a first vertebral body V 1  and a second vertebral body V 2 . For clarity of illustration, the vertebral bodies are represented schematically and those skilled in the art will appreciate that actual vertebral bodies include anatomical details not shown in  FIG. 1 . Moreover, although described in the context of being used with vertebrae, it should be appreciated the device  100  and associated methods can also be used with other skeletal segments.  
         [0075]     The device  100  generally includes a pair of anchors that include elongate distraction screws  110   a  and  110   b  (collectively screws  110 ), a platform  115 , and an insertion device  120  that is pivotably attached to the platform  115  via an attachment member. A curvilinear trocar  117  is removably mounted in a hollow shaft of the insertion device  120 . Each of the distraction screws  110  is attached at a distal end to a respective vertebral body. In this regard, the distal end of each screw can include a structure for attaching to the vertebral body, such as a threaded shank. The proximal ends of the distraction screws  110  are attached to the platform  115 . The screws  110  are axially positioned within sheaths that surround the screws and extend downwardly from the platform  115 , as described below with reference to  FIGS. 3-4 .  
         [0076]     The insertion device  120  is pivotably attached to the platform  115  such that the insertion device  120  can pivot about an axis B. The insertion device  120  includes a connecting arm  130  that extends outwardly from the platform  115 , and a curved portion  140  that curves toward the vertebral bodies from an outward tip of arm  130 . Arm  130  has a length R that corresponds to a radius of curvature of the curved portion  140 . Thus, when the insertion device  120  pivots about the axis B, the curved member  140  moves along a curved or arced pathway of radius R. The curved portion  140  can include an internal guide shaft that extends through the curved portion  140  along the entire length of the curved portion  140 . The guide shaft is sized and shaped to slidably receive the trocar  117 . The radius of curvature of the curved portion  140  can vary. As described in detail below, the curved portion  140  acts as a guide for guiding an implant device to a position between the vertebral bodies  
         [0077]      FIG. 2A  shows a perspective view of the device  100  with the insertion device  120  detached. The platform  115  includes a rail  205  that extends between the screws  110  along a direction generally parallel to the axis of the spine. As mentioned, each screw  110  extends upwardly from a respective vertebral body and attaches at a proximal end to the platform  115 . The screw  110   a  attaches to a member  207  that is fixedly attached to the rail  205 . The screw  100   b  attaches to a member  209  that is slidably attached to the rail  205 . A distraction actuator, such as a thumb screw  212 , can be actuated (such as rotated) to distract the screws  110  (and the attached vertebral bodies) relative to one another, as described below.  
         [0078]     With reference still to  FIG. 2A , a mount  210  is slidably attached to the platform  115  such that the mount  210  can slide along the length of the rail  205 , although the position of the mount  210  can be locked relative to the platform  115 , as described below. The mount  210  includes a hollow-shafted attachment screw  215  that can be used to removably attach the insertion device  120  to the platform  115 . The attachment screw  215  can also be used to attach a localizing needle (described below) to the device  100 .  FIG. 2B  shows an exploded view of the platform  115 .  
         [0079]      FIG. 3  shows a perspective view of the device  100  with the platform  115  removed from the screws  110 . As mentioned above, the screws  110   a  and  110   b  are axially positioned within corresponding sheaths  410   a  and  410   b , respectively.  FIG. 4  shows a cross-sectional view of the sheaths  410  with the screws  110  positioned therein. For clarity of illustration, the platform  115  is not shown in  FIG. 4 . Each sheath  410  has a hollow, internal shaft that is sized to slidably receive a respective screw  110 . The internal shaft of the sheath  410   a  terminates at an upward end while the internal shaft of the sheath  410   b  extends entirely through the sheath  410  to form a hole in the upper end of the sheath  410   b.    
         [0080]     With reference to  FIGS. 3 and 4 , a vertical adjustment actuator, such as a turn screw  415 , is positioned in the shaft of the sheath  410   b  above the screw  110   b . The vertical adjustment actuator is actuated to adjust the vertical position of the platform  115  relative to the vertebral bodies. It should be appreciated that use of terms such as vertical, upward, downward, etc. are with reference to the figures and are not intended to limit actual use.  
         [0081]     An exemplary configuration for such vertical adjustment is now described. An upper region of the turn screw  415  protrudes upwardly out of the platform  1115 , as best seen in  FIG. 3 .  FIG. 5  shows an enlarged, cross-sectional view of the upper region of the sheath  410   b  with the turn screw  415  and distraction screw  110   b  mounted therein. The turn screw  415  has outer threads that mate with threads on the inner shaft of the sheath  410   b . A lower edge of the turn screw  415  abuts an upper edge of the distraction screw  110   b . When the turn screw  415  is rotated, the lower edge of the screw  415  moves downwardly or upwardly depending on the direction of rotation. The abutment of the turn screw  415  with the distraction screw  110   b  causes the sheath  410   b  (and the attached platform  115 ) to rise or drop relative to distraction screw  110   b  and the vertical bodies when the turn screw  415  is rotated. In this manner, the vertical position of the platform  415  can be adjusted by rotating the turn screw  415 .  
         [0082]      FIG. 6  shows a perspective view of the device  100  with a localizing needle  610  coupled thereto. As mentioned, the localizing needle  610  can be inserted through the attachment screw  215 . The localizing needle  610  has a length such that a distal tip  615  of the needle  610  can be positioned at or substantially near a target location where an implant is to be placed. The localizing needle  610  includes one or more hatch markings  620 . Each hatch marking  620  indicates the distance from the distal tip  615  of the localizing needle  610  to the hatch marking for purposes of selecting an appropriately-sized insertion device  120  for delivering an implant to the location identified by the distal tip  615 , as described more fully below.  
         [0083]     The localizing needle  610  can be locked or unlocked relative to the platform  115 . When unlocked, the position and orientation of the localizing needle  610  can be adjusted relative to the platform  115 . For example, the localizing needle  610  can rotate or pivot to adjust the orientation of the axis of the localizing needle  610 . The localizing needle  610  can also slide relative to the rail  205  of the platform  115  by sliding the mount  210  and attachment screw  215  along the rail  205 . When locked, the position and orientation of the localizing needle  610  relative to the platform  115  is fixed.  
         [0084]      FIG. 7  shows a perspective view of the device  100  with a locking instrument  705  coupled to the platform  115  for locking and unlocking the localizing needle. The locking instrument  705  is configured to tighten onto the attachment screw  215  ( FIG. 6 ) for locking of the localizing needle  610 . When the locking instrument tightens onto the attachment screw  215 , the localizing needle locks.  
         [0085]     This is described in more detail with reference to  FIG. 8 , which shows a cross-sectional view of the locking instrument  705  attached to the platform  115  via threads that mate with threads on the locking screw  215 . The locking screw  215  has an expandable, spherically-shaped head  810  that is positioned within a socket collectively formed by the mount  210  and the rail  205 . When the locking instrument  705  is not tightened onto the attachment screw  215 , the spherical head  810  is of a size that permits the head  810  to rotate within the socket. In addition, the mount  210  and attachment screw  215  can slide along the rail  205  when the locking instrument  705  is un-tightened.  
         [0086]     However, when the locking instrument  705  is tightened, a threaded protrusion  815  causes the head  810  to expand within the socket. Specifically, the head  810  includes an upper half-sphere that contains a threaded protrusion  815 , which engages a complimentary threaded bore within a lower half-sphere. The threads are arranged so that clockwise rotation of the upper half-sphere causes the two half-spheres to separate from one another. Since the two half-spheres are housed in an enclosed space, clock-wise rotation of the locking instrument causes the half-spheres to separate and become frictionally locked relative to the rail  205  and the mount  210 . In this way, the mount  210  and attached needle  610  are locked in position relative to the platform  115 .  
         [0087]     As mentioned above with reference to  FIG. 2A , the device  100  includes a distraction actuator, such as a thumb screw  212 , that is actuated (such as by being rotated) to distract the screws  110  (and the attached vertebral bodies) relative to one another.  FIG. 9  shows a partial exploded view of the platform  115  and shows an exemplary mechanism for effectuating distraction. The thumb screw  212  attaches to an elongate, threaded lead screw  910  that can be axially inserted into one of the rails  205 , as represented by the dashed line  915 . A biasing member, such as a spring  920 , mounts onto the lead screw  910 . A pointer  925  also mounts onto the lead screw  910  for providing a measure of distraction force provided to vertebral bodies, as described more fully below. As mentioned, the member  207  is fixedly mounted to the rails  205 , while the member  209  is slidably mounted on the rails  205 .  
         [0088]      FIG. 10  shows a partial cross-sectional view of the platform  115  in an assembled state. The lead screw  910  engages threads within the rail  205  and also engages threads within the slidable member  209 . When the thumbscrew  212  is rotated, the attached lead screw  910  also rotates and moves inward or outward relative to the member  207 , which causes the slidable member  209  to move toward or away from the member  207  depending on the direction of rotation. In this manner, the vertebral bodies, which are attached to the members  207 ,  209  via the distraction screws  110  ( FIG. 2A ) and the sheaths  410 , can be distracted.  
         [0089]      FIG. 11  shows an enlarged cross-sectional view of the platform  115  in the region of the force pointer  910  that provides a measure of distraction force provided to vertebral bodies. The spring  920  is mounted on the lead screw  910  in between an internal wall of the member and a flange  1105  on the lead screw  910 . As the lead screw  910  moves along the direction  1110  in response to rotation of the thumbscrew  212 , the spring  920  compresses or expands depending on the direction of movement of the lead screw  910 . As lead screw  910  turns and members  207   209  are moved apart, pointer  925  will move relative to marking  1120  in manner directly related to the force of distraction. That is, the pointer  925  moves with the lead screw  910  and moves relative to markings  1120  wherein the position of the pointer is proportional to the spring force of the spring  920  as the spring expands and contracts. In other words, as the distraction screws  110  and attached vertebral bodies are distracted, the pointer  925  moves relative to the markings  1120  to provide an indication as to force of distraction. The configuration of the hatch markings  1120  can vary. The hatch markings  126  may provide an actual measure of the distraction force in a recognized physical unit or simply give an arbitrary number, letter, or designation to which the operator would distract the vertebral bodies.  FIG. 12  shows an enlarged view of the pointer  925  and the markings  1120  on the platform.  
         [0090]     There is now described a method of use for the device  100 . The patient is first placed in a position suitable for the procedure. For example, the patient is placed on his side or in the prone position. The hips and knees are flexed and the procedure is performed under x-ray guidance. The vertebral bodies at the diseased level(s) are identified radiographically and the bone screws  110  are percutaneously inserted into the spinous processes of the upper and lower vertebras. The device  100  is then coupled to the distraction screws  110  by sliding the sheaths  410  over the distraction screws, as shown in  FIG. 3 . For clarity of illustration, certain anatomical details, such as the patient&#39;s skin, are not shown in  FIG. 3  and in some other figures.  
         [0091]     As shown in  FIG. 6 , the localizing needle  610  is placed through the platform  115  and percutaneously guided into the inter-spinous space at the stenotic level. Under X-ray guidance, the needle&#39;s distal tip  615  is advanced until it lies where the operating surgeon wishes to place the implant. At this stage, the localizing needle  610  is in the unlocked state so that the surgeon can adjust the position and orientation of the needle. Once the surgeon has located the distal tip  615  so that it lies at a target location where the operating surgeon wishes to place the implant, the locking instrument  705  is locked onto the device, as shown in  FIG. 7 .  
         [0092]     As discussed and as shown in  FIG. 13 , the localizing needle  610  has one or more hatch markings  620  that indicate the distance from the distal tip  615  to the radial center of rotation of the guide arm. That distance can be illustrated at each hatch mark on the needle  610 , although the distance is not shown in  FIG. 13  for simplicity of illustration. After the needle&#39;s distal tip  615  is placed in the desired position, the position of the needle&#39;s hatch marks relative to the top of the locking instrument  705  is noted. The distractor device  100  is then moved upwards (or downward) by manipulating the turn screw  415  until the hatch mark immediately above the locking instrument  705  rests immediately adjacent the top of the instrument  705 , as shown in  FIG. 14 .  FIG. 15A  shows the device with the platform  115  positioned before it had been moved by the turn screw  112  while  FIG. 15B  shows the platform  115  after movement. Note that the bottom portion of the distractor platform has displaced upward relative to the distraction bone screws.  
         [0093]     At this stage of the procedure, the localizing needle  610  is locked in place with the marking  620  on the needle providing an indication as to the radius of rotation of the insertion member  120  to be mounted to the platform  115 . With the needle and platform locked, the vertebral bodies are then distracted. This is accomplished by turning the thumb screw  212  which, in turn, moves the lead screw  910  and distracts the member  207  relative to the member  209  in the manner described above. As mentioned, the pointer  925  in combination with the markings  925  provide an actual measure of the distraction force in a recognized physical unit or provide an arbitrary number, letter, or designation to which the operator would distract the vertebral bodies.  
         [0094]     At this stage of the procedure, the localizing needle  610  is fixed in place, the platform  115  is locked in position, and the vertebral bodies are distracted with the distraction force indicated by the pointer  925 . A swing arm is selected with a radius R equivalent to the number, letter or designation of the hatch mark on the localizing needle  610  (the hatch mark  620  at the level of the top of locking instrument). Thus, when the insertion device  120  is pivoted about the axis B ( FIG. 1 ), the curved portion  140  moves along a pathway that intersects the target location defined by the distal tip of the localizing needle  610 .  
         [0095]      FIG. 16  is a perspective view of the device showing how the insertion device  120  is pivotably attached to the platform  115 . The insertion device  120  includes an attachment member  1710  ( FIGS. 17A and 17B ) that removably mates with the attachment screw  215  by lowering the attachment member  2210  onto the attachment screw  215 , as represented by the arrow  2110  in  FIG. 16 .  
         [0096]      FIGS. 17A and 17B  show enlarged views of the attachment member  1710  of the insertion device  120  being lowered onto the attachment screw  215  of the platform  115 .  FIG. 18  shows a cross-sectional view of the attachment member  1710  attached to the attachment screw  215 . The attachment member  1710  includes an attachment screw  1715  that has a threaded bore that mates with a shank of the attachment screw  215 . Once attached, the insertion device  120  can pivot about the axis B.  
         [0097]     At this stage of the procedure, the device  110  including the pivotably mounted insertion device  120  is attached to the pair of vertebral bodies, as shown in  FIG. 19 . The insertion device  120  is positioned such that a distal tip  1910  of the curved portion  140  is positioned above the level of the patient&#39;s skin. For clarity of illustration, the skin is not illustrated in  FIG. 19 .  
         [0098]      FIG. 19  shows the insertion device  120  prior to insertion of the trocar  117  into the internal shaft of the curved portion  140 .  FIG. 20  shows the device  100  with the trocar  117  positioned within the curved portion  140  of the insertion device  120 . The trocar has a handle on one end and a sharp, knife-like tip  2010  at an opposite end.  
         [0099]      FIGS. 20-22  sequentially illustrate how the insertion device  120  swings toward the target location where the implant is to be positioned. As mentioned, as the insertion device  120  pivots, the distal end  1910  of the curved portion  140  moves along a curvilinear pathway that intersects the target location. In  FIG. 20 , the tocar  117  is slid into the internal shaft of the curved portion  140 . The handle of the trocar  117  is then pushed toward the skin so that the distal end  1910  swings toward the skin along a pathway D. The sharp, knife-like tip of the trocar  117  cuts through the skin and soft tissue as the insertion device  120  swings toward the skin. The trocar  117  and the curved portion  140  are then forced through the skin and soft tissue as illustrated in  FIGS. 21 and 22  until the distal tip  1910  of the curved portion  140  abuts the side of the spinous processes of the vertebral bodies. Since the swinging insertion device  120  rotates about the locked platform  115  and arm  130  has a radius equivalent to the distance between the center of rotation and the needle tip, the curved portion  140  will necessarily travel along an arc that intersects the position of the needle tip. As shown in  FIG. 23 , the trocar  117  is then removed leaving the central shaft  2310  of the curved portion  140  of the insertion device free as a conduit for implant placement.  
         [0100]     In the next step, the appropriate size of the implant is determined, wherein the appropriate size is based upon the size of the space between the two spinous processes.  FIGS. 24A, 24B , and  24 C show an exemplary sizing device  2410  for determining the appropriate size of an implant. The sizing device  2410  is an elongate rod that is sized to be positioned within the shaft  2310  of the curved portion  140 . A proximal end of the sizing device  2410  has hatch marks  2414 . A distal end  2415  of the sizing device has a gradually reducing diameter. As the sizing device  2410  is advanced further into the curved portion and into the space between the spinous processes, the distal end  2415  of the sizing device  2410  begins to distract the spinous processes and thereby unload the distractor.  
         [0101]     Distraction of the spinous processes can be easily recognized by movement of pointer  925  ( FIG. 12 ) relative to hatch marks  1120 . That is, as the sizing device  2410  is advanced, the pointer  925  will indicate that less force is borne by the distraction screws  110 . Once the sizing device  2410  is advanced sufficiently to unload the distraction screws, the implant size is noted on hatch markings  2414  on the sizing device  2410 . For illustration, this size is shown as “11” in  FIG. 24B . It should be appreciated that this number may provide an actual measure of the implant size in a recognized physical unit or simply give an arbitrary designation by which the implants are labeled. With the implant size determined, the sizing device  2410  is removed and the appropriate implant is selected.  
         [0102]      FIGS. 25 and 26  show an implant holder device  2510  that can be used to hold an implant  2515  and install the implant via the internal shaft in the curved portion  140  of the install device  120 . The holder device  2510  includes a handle assembly  2520  having a pair of arms  2522  and  2524 . A curved member  2530  extends outwardly from the handle assembly  2520 . The curved member  2530  is coupled to a member  2535  and a member  2540 , which are movable relative to one another in response to actuation of the handles  2522 ,  2524 . The members  2530 ,  2535 , and  2540  collectively form a holder element that holds and secures the implant  2515 . The implant  2515  has a curvilinear shape and mounts onto the members  2535  and  2540 , as shown in  FIG. 26  and described below.  
         [0103]      FIGS. 27A and 27B  show the implant  2515  with extendable wings  2710  in an undeployed ( FIG. 27A ) and a deployed state ( FIG. 27B ). The implant  2515  has an internal bore  2715 . The wings  2710  are formed of foldable arms  2720 . The implant  2515  also includes ratchets  2730  that are engageable by protrusions  2735 . An indentation  2732  is located along a proximal edge of the implant  2515 . When the implant  2515  is positioned within the space between the spinous processes, the implant  2515  is collapsed along its length, which causes the arms  2720  to fold outward and form the wings  2710 . The protrusions  2735  engage the ratchets  2730  to lock the implant in the deployed state.  
         [0104]     The implant  2515  mounts onto the holder  2510  by sliding the members  2535 ,  2540  through the bore  2715  in the implant  2515  such that the implant  2515  is positioned over the members  2535 ,  254 , as shown in  FIG. 26 . When the implant  2515  is mounted as such, a protrusion  2810  on the distal edge of the member  2530  engages the indentation  2732  on the proximal edge of the implant  2515 , as shown in  FIG. 28 . The engagement prevents the implant  2515  from rotating when mounted on the members  2530 ,  2540 .  
         [0105]      FIG. 29  shows a cross-sectional view of the implant attached to the holder.  FIG. 30  shows a close-up view of the implant attached to the holder. The members  2535  and  2540  of the holder  2510  are both positioned within the central bore  2715  and engage the head of the implant. A handle  2910  on the assembly  2520  is actuated to cause the member  2540  to move back relative to the member  2535  and expand a split ring  3010 . As the split ring  3010  expands, the ring  3010  wedges against the internal wall of the bore  2715  and thereby lock the implant  2515  onto the implant holder  2510 . The locking mechanism at the head of the implant and the prevention of rotation (by engagement of protrusion  2810  and indentation  2732  as shown in  FIG. 28 ) effectively immobilize the implant  2515  relative to the holder  2510 .  
         [0106]      FIG. 31  shows the implant  2515  locked onto the holder  2510  with the handle  2910  in a locked position.  FIG. 32  shows a close-up, cross-sectional view of the implant end of the holder  2510 . Note that the split ring  310  now abuts the inside of the bore  2715  and a conical head  3110  of the member  2540  is situated at the distal tip of the implant  2515 .  
         [0107]     At this stage of the procedure, the implant  2515  is locked onto the holder  2510  pursuant to the above-described process. The holder  2510  and the attached implant  2515  can now be inserted into the internal shaft of the curved member  140  of the insertion device  120 .  FIG. 33  shows the holder  2510  and attached implant  2515  just prior to insertion into the internal shaft  2310  of the curved portion  140 . The holder  2510  and attached implant  2515  are slid through the internal shaft  2310  until the implant protrudes out of the curved portion and is positioned between the spinous processes, as shown in  FIG. 34 . If needed, a mallet may be used to apply force to surface  3410  of the implant holder  2510  in order to position the implant between the spinous processes.  
         [0108]     The handles  2522  and  2524  of the implant holder  2510  are then actuated, which causes the ends of members  2530  and  2535  to move towards one another. The actuation of the handles  2522  and  2524  causes the implant to deform such that the wings  2710  are deployed, as shown in  FIG. 35 .  
         [0109]      FIG. 36  shows a cross-sectional view of the deployed holder and implant.  FIG. 37  shows a close-up view of the implant coupled to the holder  2510 . The handle  2524  and  2522  are connected to a mechanism that causes the members  2530  and  2535  to move when the handles are actuated. The movement causes the implant wings to deploy. Note that the implant&#39;s ratchet locking mechanism (the ratchets  2730  and protrusions  2735 ) is now locked and keeps the implant in the deployed position. At this stage, the handle  2910  can be unlocked and the implant holder  2510  removed form the central channel of the curved portion  140  of the installer device  120 .  FIG. 38  shows the implant  2515  deployed between the vertebral bodies and the holder removed from the device  100 .  FIG. 39  shows the implant  2515  deployed between the vertebral bodies after the inserter device  120  has been rotated out of the soft tissue and the device  100  and distraction screws have been removed.  
         [0110]     With reference again to  FIG. 27 , the implant  2515  includes a screw  2740  that secures a first portion of the implant to a second portion of the implant. When the screw  2740  is in place, the first portion and second portion are secured to one another. When the screw  2740  is removed, the first portion and second portion detach from one another. The implant  2515  can advantageously be disassembled by removing the screw  2740 . If open surgery is required at a future date, the implant  2515  can be disassembled and completely removed—making the implantation procedure completely reversible.  FIG. 40  shows how the screw  2740  may be removed and the implant divided into subunits comprised of a first portion  4010  and a second portion  4015 . This permits the removal of each subunit without removal of the interspinous ligament.  
         [0111]      FIG. 41  shows another embodiment of a device with a swinging or pivoting installer device  120  having a structure similar to the installer device  120  described above. Thus, like reference numerals refer to like structures. In this embodiment, the installer device  120  mounts at the proximal end of a single mounting post  4110  that attaches at a distal end to the spinous process of a vertebral body V 1  or V 2 .  
         [0112]      FIG. 42  shows the mounting post  4110  in an exploded state. The mounting post  4110  includes a screw  4205  with a shank that screws into the spinal process. A two-piece post portion couples to the screw  4205 . The post portion has an internal member  4210  positionable inside an external member  4215 . The internal member  4210  and the external member  4215  are coupled to one another to form the elongate mounting post  4110 , as shown in  FIG. 43 .  
         [0113]     Under X-ray guidance, the screw  4205  of the post  4110  is percutaneously attached onto the spinous process through a small skin incision. The internal member  4210  of the post  4110  is configured to lock to the screw  4205  while the screw  4205  is being driven into bone. In this way, rotation of the outer member  4215  causes advancement of the screw into the spinous process. The internal member  4210  is then unlocked and the external member  4215  is moved in the long axis of the spine until the free end of the post  4110  rests along a line L parallel to the inter-spinous space, as shown in  FIG. 44 . The inter-spinous space is easily identified on X-rays. After this is performed, the internal member  4215  is locked, which immobilizes the post  4110  relative to the screw  4205 .  
         [0114]     After the post-screw is appropriately positioned, the installer device  120  is attached onto the proximal end of the post  4110  as shown in  FIGS. 45 and 46 . An attachment member  4125  pivotably attaches the insertion member  120  to the proximal end of the post  4110 . The attachment member  4125  is configured to permit the insertion member  120  to pivot about a pivot axis B (shown in  FIG. 46 ).  
         [0115]      FIG. 47  shows an enlarged, exploded view of the attachment member  4125  positioned adjacent an attachment region of the insertion device  120 .  FIG. 48  shows a perspective, cross-sectional, assembled view of the attachment member  4125 . The attachment member  4125  includes a main body  4510  having a rounded protrusion  4515  that can be positioned inside the proximal end of the post  4110 . A pair of side walls  4520  having inwardly extending teeth  4525  are positioned on opposite sides of the main body  4510 . As mentioned, the structural configuration of the attachment member  4125  can vary and is not limited to the embodiment described herein.  
         [0116]     With reference to  FIG. 47 , the attachment member  4125  is attached to the post  4110   115  by inserting the rounded protrusion  4515  into the proximal end of the post  4110 . The two side walls  4520  are positioned on either side of the post  4110  such that each tooth  4525  engages a corresponding slot  4530  on the post  4110 . In this manner, the attachment member  4125  is attached to the post  4110 .  
         [0117]     With reference to  FIGS. 47 and 48 , a pivot rod member  4540  is positionable inside the main body  4510 . The pivot rod member  4540  includes a pivot rod  4545  that protrude outwardly from opposed sides of the main body  4510  when the pivot rod member  540  is positioned inside the main body  4510 . The pivot rod  4545  can be inserted into a pair of apertures  4555  ( FIG. 47 ) on the insertion device  120  to pivotably couple the insertion device  120  to the post  4110  via the attachment member  4125 . The pivot rod  545  defines the pivot axis B ( FIG. 46 ) for pivoting of the insertion device  120 .  
         [0118]      FIG. 49  shows a side view of an elongate plunger  4810  that slidably fits within a guide shaft inside the curved portion  140  of the insertion device  120 . The plunger  4810  has a tapered tip  4815  on a distal end and a handle  4820  on a proximal end. When the plunger  4810  is fully positioned in the guide shaft, the handle  4820  protrudes out of one end of the guide shaft and the tapered tip  4815  protrudes out of the opposite end of the guide shaft.  FIG. 50  shows a side view of the device with the plunger  4810  positioned inside the curved portion  140  of the insertion device  120 .  
         [0119]     With the insertion device  110  attached to the post  4110 , the handle  4820  of the plunger  4810  is then used to push curved portion  140  toward the skin. As the tip  4815  abuts the skin, a small incision is made and the curved portion is then rotated further until the tapered end  4815  contacts the lateral side of the inter-spinous space, as shown in  FIG. 50  and  FIG. 51 .  
         [0120]     The plunger  4810  is removed and an orthopedic device can then be placed into the inter-spinous space through the guide shaft comprised of open curvilinear central bore of the curved portion  140 . In this way, a device can be precisely delivered into the inter-spinous space with minimal tissue dissection. This method will provide a minimally invasive way of implanting orthopedic devices into this space.  
         [0121]     In other embodiments, one or more anchors may be placed into the inter-spinous ligament, lateral to the inter-spinous space, into the pedicles or any other suitable anchor point. The insertion device is then attached and rotated onto the lateral aspect of the inter-spinal space. Lastly, the curved portion  140  of the insertion device  120  may be designed without a central bore for implant insertion. Instead, the implant is attached to the tip of the curved portion  140  and delivered by rotation of the curved portion. Once in place, the implant is detached from the insertion device  120 .  
         [0122]      FIGS. 52 and 53  shows another embodiment of a distractor device  5210  that is similar to the distractor device  100  described above. In this embodiment, the distractor device  5210  is attached to a pair of distractor members  5315  and  5215  that engage the first and second vertebral bodies. The distractor member  5215  is an elongate rod having a sharpened distal end for penetrating the skin. As shown in  FIG. 53 , the distal end does not penetrate the vertebral body but rather engages the vertebral body by abutting a side of the vertebral body.  
         [0123]     It should be appreciated that the distractor members can engage the vertebral bodies in various ways. For example, the distractor members can be anchors with shanks that actually penetrate into the vertebral bodies. The distractor members can also be clamps that clamp onto the vertebral bodies or can simply by shaped to abut a portion of the vertebral body to purchase onto the vertebral body for distraction purposes. In addition, one of the distractor members can engage a first vertebral body in one manner (such as by penetrating the vertebral body) and the other distractor member can engage a vertebral body in another manner, such as by simply abutting or clamping onto the vertebral body. Alternately, both distractor members can simply abut a respective vertebral body without any penetration of the vertebral bodies by the distractor members.  
         [0124]     As shown in  FIG. 53 , the distractor member  5215  has a structural configuration wherein an anchor  5310  anchors into the respective vertebral body. The anchor  5310  fits into a sheath  5315  that extends downward from a member  5320  on a platform  114 . A vertical adjustment actuator  5325  is located on the member  5320  for adjusting the vertical position of the platform  114  in the manner described above with reference to the previous embodiment.  
         [0125]     Although embodiments of various methods and devices are described herein in detail with reference to certain versions, it should be appreciated that other versions, embodiments, methods of use, and combinations thereof are also possible. Therefore the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.