Patent Publication Number: US-2022211513-A1

Title: Cervical distraction/implant delivery device

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application is a continuation of U.S. application Ser. No. 15/488,989 filed Apr. 17, 2017 and entitled Cervical Distraction/Implant Delivery Device (the &#39;989 application). The &#39;989 application is a continuation of U.S. application Ser. No. 13/949,042 filed Jul. 23, 2013, and entitled Cervical Distraction/Implant Delivery Device (the &#39;042 application), now U.S. Pat. No. 9,622,874. The &#39;042 application is a continuation of U.S. application Ser. No. 12/559,193 filed Sep. 14, 2009 and entitled Cervical Distraction/Implant Delivery Device (the &#39;193 application), now U.S. Pat. No. 8,512,347. The &#39;193 application is a continuation-in-part of U.S. application Ser. No. 12/455,814 filed Jun. 5, 2009, and entitled Facet Joint Implants and Delivery Tools (the &#39;814 application), now U.S. Pat. No. 8,361,152. The &#39;814 application is a continuation-in-part of U.S. application Ser. No. 12/317,682 filed Dec. 23, 2008, and entitled Facet Joint Implants and Delivery Tools (the &#39;682 application), now U.S. Pat. No. 8,267,966. 
     The &#39;193 application also claims priority from: U.S. Provisional Application No. 61/169,601 filed Apr. 15, 2009 and entitled Facet Joint Implants and Delivery Tools; U.S. Provisional Application No. 61/109,776 filed Oct. 30, 2008 and entitled Facet Joint implants; and U.S. Provisional Application No. 61/097,103 filed Sep. 15, 2008 and entitled Cervical Distraction/Implant Delivery Device. 
     The &#39;682 application claims priority from U.S. Provisional Application No. 61/059,723 fled Jun. 6, 2008 and entitled Spine Distraction Device. 
     The contents of all of the above applications are hereby incorporated by reference herein in their entireties. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     This invention pertains generally to a cervical distraction device and more particularly to such a device that cannot only distract a facet joint but also deliver an implant to the distracted joint. 
     Description of the Relevant Art 
     Chronic back problems cause pain and disability for a large segment of the population. Adverse spinal conditions are characteristic of age. With aging, generally comes an increase in spinal stenosis (including, but not limited to, central canal and lateral stenosis), and facet arthropathy. Spinal stenosis results in a reduction of foraminal area (i.e. the available space for the passage of nerves and blood vessels), which compresses the cervical nerve roots and causes radicular pain. Extension and ipsilateral rotation of the neck further reduces the foraminal area and contributes to pain, nerve root compression, and neural injury. However, neck flexion generally increases the foraminal area. 
     Cervical disc herniations predominantly present upper extremity radicular symptoms. The vast majority of these hernations do not have an associated neurological deficit and present pain only. A well-described treatment for cervical disc herniations is closed traction. There are a number of marketed devices that alleviate pain by pulling on the head to increase foraminal height. 
     Cervical disc herniations have been treated with anterior and posterior surgery. The vast majority of these surgeries are performed through an anterior approach, which requires a spinal fusion. These surgeries are expensive and beget additional surgeries due to change in biomechanics of the neck. There is a three percent incidence of re-operation after cervical spine surgery. 
     It Is an object of the present invention to provide a minimally invasive device and procedure to increase foraminal height to reduce radicular symptoms for patients with disc herniations. 
     SUMMARY OF THE INVENTION 
     In one embodiment, a distraction tool for distracting a facet joint can include a handle, a cannula extending from the handle, and a distraction mechanism positioned on a distal end of the cannula and adapted to be placed in the facet joint. In this embodiment, the handle can be in communication with the distraction mechanism and actuation of the handle can cause distraction thereof. 
     In another embodiment, a distraction mechanism for distracting a facet joint can be provided. The mechanism can include a head in the form of an oblong band and an elongate member extending through the head. The elongate member can be adapted to draw opposing ends of the head toward one another thereby expanding the head. 
     In still another embodiment, a distraction mechanism can include a plurality of pairs of teeth in pivotal relation with a central core and an elongate member extending through the central core. Actuation of the elongate member can cause distraction of at least one of the plurality of pairs of teeth. 
     In still another embodiment, a distraction mechanism can include a hollow elongated body having facet engaging features and an elongated member adapted for insertion within the body. Insertion of the elongated member can actuate the facet engaging features. 
     In still another embodiment, a distraction mechanism can include an expandable receiving portion having upper and lower generally planar elements connected at an end with a living hinge. The distraction mechanism can also include an actuation device adapted to be placed between the planar elements. The planar elements can include malleable material that conforms to the facet surface upon implantation. 
     In yet another embodiment, a delivery tool for positioning a distraction mechanism in a facet joint can include a distraction mechanism for distracting a facet joint and a handle and a cannula connected to one another and carrying said distraction mechanism on a distal end thereof. The handle can include means for delivering energy to said distraction mechanism, and said distraction mechanism can be manipulatable to increase the spacing of said confronting facets thereby distracting said facet joint. 
     A device and technique are disclosed for a minimally invasive surgical implantation to reduce radicular symptoms by inserting a distraction mechanism in a facet joint of an affected level of the spine to preserve the physiology of the spine. In particular, embodiments of the present invention provide for distracting and translating the cervical spine to increase the foraminal dimension in extension and neutral positions. The distraction mechanism may have a portion which can serve as an implant or It may be a mechanism for facilitating insertion of a separate implant. When the distraction mechanism is positioned in the cervical facet joint, it expands to distract or increase the space between the vertebrae to increase the foraminal area or dimension and reduce pressure on the nerves and blood vessels of the cervical spine. The devices and techniques disclosed supplement those disclosed in U.S. nonprovisional patent application Ser. No. 111618,619 filed Dec. 29, 2006, entitled Cervical Distraction Device, and U.S. provisional patent application Ser. No. 61/059,723, filed Jun. 6, 2008, entitled Spine Distraction Device, which are of common ownership with the present application, the disclosures of which are hereby incorporated by reference. 
     The implantation procedure may be performed under conscious sedation in order to obtain intra-operative patient symptom feedback. 
     After achieving the desired distraction of the facet joint, the distal tip of the distraction tool may be detached from the tool so the distraction device itself serves as a permanent implant for placement in the facet joint. The patient is left with the distraction device implant in the facet joint with permanent increased foraminal height. As an alternative, the distraction device can be removed from the distracted joint after a separate or auxiliary insert is positioned in the joint. 
     While the implant may comprise an inflatable balloon configured to be filled with an inflation medium, e.g. hydrogel or the like, to distribute a compressive load on the articulating surfaces as disclosed in the aforenoted U.S. nonprovisional patent application Ser. No. 11/618,619, pursuant to the present invention, the implant may also be a mechanical device that does or does not expand or inflate. 
     The implant is configured to dynamically stabilize or fuse the facet joint and retain it in an expanded or distracted condition. The implant maintains a minimal distance between the articulating surfaces and, in some embodiments, allows motion of a first vertebra with respect to a second adjacent vertebra. 
     According to the technique of the invention, an expandable or non-expandable distraction device is inserted in a collapsed state into a facet joint bounded by first and second vertebrae, and is expanded within the facet joint to increase a foramina) dimension associated with the first and second vertebrae. The implant is installed in a facet joint located between adjacent cervical vertebrae. The expandable implant engages the articulating surfaces of the facet joint to increase the distance between the articulating surfaces. 
     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 fragmentary isometric of a portion of the human spine showing a facet joint which may be treated with the devices and techniques of the present invention to distract the facet joint and retain it in an expanded condition. 
         FIG. 2  is an isometric similar to  FIG. 1  viewed from a different direction. 
         FIG. 3  is an isometric similar to  FIG. 2  with a distraction device in accordance with the present invention having its distal end inserted into the facet joint and having an implant device releasably held in the distal end. 
         FIG. 4  is an isometric similar to  FIG. 3  with the implant having been positioned within the facet joint to retain the distracted position of the joint. 
         FIG. 5  is a section taken through the spinal column showing implant in position on bilateral facets. 
         FIG. 6A  is an isometric section with parts removed of a first embodiment of a distraction device in accordance with the present invention. 
         FIG. 6B  is a diagrammatic side elevation of the device of  FIG. 6A  with the distal tip of the device positioned within a facet joint. 
         FIG. 6C  is an elevation similar to  FIG. 6B  with the device expanded to distract the facet joint. 
         FIG. 7A  is a fragmentary isometric of a second embodiment of the distraction device of the present invention. 
         FIG. 78  is a side elevation of the device of  FIG. 7A  having its distal tip of the device inserted into a facet joint. 
         FIG. 7C  is an elevation similar to  FIG. 7B  with the distal tip expanded to distract the facet joint. 
       FIG. BA is an isometric of an expandable tip of a distraction device showing a third embodiment of the present invention. 
         FIG. 8B  is a side elevation showing the device of  FIG. 8A  positioned on the distal end of a distraction tool with the device inserted into a facet joint. 
         FIG. 8C  is a side elevation similar to  FIG. 88  with the device expanded to distract the facet joint. 
         FIG. 9A  is a fragmentary isometric of the distal tip of a distraction device showing a fourth embodiment of the present invention. 
         FIG. 98  is a side elevation showing the device of  FIG. 9A  positioned in a facet joint. 
         FIG. 9C  is a side elevation similar to  FIG. 96  with the device expanded. 
         FIG. 10A  is an isometric of a fifth embodiment of the device of the present invention. 
         FIG. 10B  is an isometric similar to  FIG. 10A  with the device expanded. 
         FIG. 10C  is a side view showing the device of  FIG. 10A  positioned on the distal end of a distraction tool. 
         FIG. 10D  is a side view similar to  FIG. 10C  with the device expanded as in  FIG. 10B  and separated from the insertion tool. 
         FIG. 11A  is a fragmentary isometric of a sixth embodiment of the present invention. 
         FIG. 11B  is a side view showing the device of  FIG. 11A  inserted into a facet joint. 
         FIG. 11C  is a side view similar to  FIG. 11B  with the device having been rotated with the insertion tool to distract the facet joint. 
         FIG. 12A  is an isometric of the handle of a seventh embodiment of the present invention. 
         FIG. 12B  is the distal tip of the seventh embodiment of the handle which is shown in  FIG. 12A . 
         FIG. 12C  is a transverse section of the distal tip as shown in  FIG. 12B . 
         FIG. 12D  is a diagrammatic cross-section through a facet joint with the device of  FIG. 12B  positioned therein and having injected a gel substance into the facet joint. 
         FIGS. 13A and 13B  are fragmentary isometric views of a tip of a distraction device in accordance with the present invention showing an eighth embodiment of the distal tip of the device. 
         FIG. 13C  is a side view of a tool inserting the device of  FIG. 13A  into a facet joint. 
         FIG. 13D  is a side view similar to  FIG. 13C  with the device of  FIG. 13A  having been rotated to distract the facet joint and the insertion device removed from the tip which serves as an implant. 
         FIGS. 13E-13H  are respectively the same views as depicted in  FIGS. 13A-13D , except of a variation of the embodiment depicted in  FIGS. 13A-13D . 
         FIG. 14A  is an isometric showing the tip of a ninth embodiment of a distraction device in accordance with the present invention. 
         FIG. 14B  is a side view showing the distraction device of  FIG. 14A  inserted into a facet joint with an insertion tool. 
         FIG. 14C  is a side view similar to  FIG. 14B  with a plurality of blades or spatula elements having been advanced into the facet joint to distract the joint. 
         FIG. 15A  is an isometric of a tenth embodiment of a distraction device in accordance with the present invention. 
         FIG. 15B  is a side view of the device shown in  FIG. 15A  on the distal end of an insertion tool and positioned within a facet joint. 
         FIG. 15C  is a side view similar to  FIG. 15B  with the distraction device having been expanded to distract the facet joint and delver a permanent implant into the distracted joint. 
         FIG. 16A  is a side view of an eleventh embodiment of a distraction device in accordance with the present invention, showing a wedge option, an elongated member option, and a block option. 
         FIG. 16B  is an isometric of the wedge option of  FIG. 16A . 
         FIG. 16C  is a side view of the distraction device of  FIG. 16A  positioned within a facet joint on the distal tip of an insertion tool. 
         FIG. 16D  is a side view similar to  FIG. 16B  with the distraction device expanded to distract the facet joint and with the insertion tool having been separated therefrom. 
         FIG. 17A  is an isometric of a twelfth embodiment of a distraction device in accordance with the present invention. 
         FIG. 17B  is a side view of the device of  FIG. 17A  positioned in a facet joint and on the end of an insertion tool. 
         FIG. 17C  is a side view similar to  FIG. 17B  with the device of  FIG. 17A  having been expanded and the insertion tool separated therefrom to leave the device as an implant in a distracted facet joint. 
         FIG. 18A  is a diagrammatic fragmentary isometric with parts removed illustrating a thirteenth embodiment of the present invention. 
         FIG. 18B  is a fragmentary diagrammatic vertical section through the device shown in  FIG. 18A . 
         FIG. 19A  is a fragmentary diagrammatic similar to  FIG. 18A  showing an alternative fourteenth embodiment. 
         FIG. 19B  is a fragmentary vertical section similar to  FIG. 18B  showing the alternative embodiment of  FIG. 19A . 
         FIG. 20A  is an isometric of a fifteenth embodiment of a distraction device in accordance with the present invention. 
         FIG. 20B  is an enlarged fragmentary isometric view of the distal tip of the device of  FIG. 20A . 
         FIG. 20C  is a diagrammatic vertical section showing the device of  FIG. 20A  inserted into a facet joint. 
         FIG. 21A  is an isometric of a sixteenth embodiment of a distraction device in accordance with the present invention. 
         FIG. 21B  is an enlarged fragmentary isometric of the distal tip of the device of  FIG. 21A . 
         FIG. 21C  is a diagrammatic vertical section showing the device of  FIG. 21A  inserted into a facet joint. 
         FIG. 22A  is an isometric of a seventeenth embodiment of the distraction device of the present invention. 
         FIG. 22B  is an enlarged fragmentary isometric of the distal tip of the device of  FIG. 22A  in a closed position. 
         FIG. 22C  is a fragmentary isometric similar to  FIG. 22B  with the tip in an expanded position. 
         FIG. 22D  is a diagrammatic vertical section showing the device in the expanded condition of  FIG. 22C  inserted into a facet joint. 
         FIG. 23A  is an isometric of an eighteenth embodiment of the distraction device in accordance with the present invention. 
         FIG. 23B  is an enlarged fragmentary isometric showing the tip of the device of  FIG. 23A  in a closed position. 
         FIG. 23C  is a fragmentary isometric similar to  FIG. 23B  with the tip in an expanded position. 
         FIG. 23D  is a diagrammatic vertical section showing the device in the expanded position of  FIG. 23C  inserted into a facet joint. 
         FIG. 24A  is an isometric of a nineteenth embodiment of the distraction device of the invention. 
         FIG. 24B  is an enlarged fragmentary isometric of the tip of the device of  FIG. 24A  in a closed position. 
         FIG. 24C  is a fragmentary isometric similar to  FIG. 24B  with the tip expanded. 
         FIG. 24D  is a diagrammatic vertical section showing the device in the expanded position of  FIG. 24C  inserted into a facet joint. 
         FIG. 25A  is an isometric of a first embodiment of an implant for delivery with or in conjunction with a distraction device. 
         FIG. 25B  is an isometric of a second embodiment of an implant. 
         FIG. 25C  is an isometric of a third embodiment of an implant. 
         FIG. 25D  is an isometric of a fourth embodiment of an implant. 
         FIG. 25E  is an isometric of a fifth embodiment of an implant. 
         FIG. 25F  is an isometric of a sixth embodiment of an implant. 
         FIG. 26A  is an isometric of a twentieth embodiment of the distraction device in accordance with the present invention. 
         FIG. 26B  is a vertical section through the distal tip of the device of  FIG. 26A  in a closed position. 
         FIG. 26C  is a vertical section similar to  FIG. 26A  with the distal tip expanded. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Pursuant to the present invention, devices and techniques for distracting and retaining a facet joint in a distracted and forwardly translated condition are disclosed. Prior to distracting the facet joint, the joint, which can be difficult to access, can be accessed pursuant, for example, to the method and apparatus disclosed in U.S. Non-provisional application Ser. No. 12/350,609, 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 is comprised of one or more cannulas made of steel, titanium, or plastic. The initial facet joint access cannula can have a sharp spatula tip on the distal end. The spatula tip can have a flat configuration to enable access into the flat facet joint. Once the spatula tip achieves access into the generally flatly oriented facet joint, subsequent stylets and working instruments can be passed down this access channel to complete a distraction procedure. The distraction procedure can be accomplished with devices and techniques to be described hereafter. 
     The percutaneous distraction mechanism can be introduced down the working cannula of the above-identified access system. The mechanism can be part of a delivery tool that would allow the surgeon to generate distraction by applying energy to a handle of the delivery tool for the distraction mechanism positioned at the distal end of the tool. The handle of the delivery tool can be configured in any number of ways including but not limited to the following: 
     a) Trigger grip—index finger activates distraction by pulling the trigger to apply energy to the distraction mechanism. 
     b) Scissor grip—index and middle fingers meet and separate to apply energy to the distraction mechanism. 
     c) Thumb wheel or slide—thumb rolls a wheel or slides a slide that progressively applies more energy to the distraction mechanism. 
     d) Thumb cushion rod—thumb plunges a stylet down the working cannula to apply energy to the distraction mechanism. 
     e) Stylet screwdriver—stylet is threaded down the working cannula into the distraction mechanism applying increasingly more energy to the distraction mechanism as the stylet screwdriver advances. 
     f) Mallet based handle—a stylet with a flat malleable surface is inserted for the purposes of receiving and dispersing mallet energy and applying it to the distraction mechanism. 
     g) Thumb button—a button on the proximal end of the handle is pushed which creates one of a number of mechanical systems to apply energy to the distraction mechanism. Those mechanical systems could include but are not limited to:
         i) hydraulic pressure generation;   ii) mechanical drill;   iii) level system; or   iv) elastic bands with “rope and pulley” mechanism.       

     h) Wedge firestarter—triangular wedge located at the proximal end of the tool is flattened to generate energy to apply to the distraction mechanism. 
     i) Foot or hand pump—feet or hands of surgeon used to press the system to create energy to be applied to the distraction mechanism. 
     Referring to  FIGS. 1-5 , a description relating to any and/or all of the delivery tools and associated distraction mechanisms and implants disclosed herein is presented. Referring first to  FIG. 1 , a portion of a spinal column  30  is shown having facets  32  on vertebrae  34  and with facet joints  36  between adjacent facets  32  of the vertebrae  34 . The spinal cord  38 , of course, passes vertically through the aligned vertebrae  34  with peripheral nerves  40  passing from the spinal cord  38  outwardly through the spinal column  30  through foraminal openings  42  to predestined locations in the human body. When facet joints  36  become narrowed, usually from disc degeneration, the foraminal openings  42  are reduced in size pinching the nerve and causing pain to the individual. 
     Pursuant to the present invention, the facet joint  36 , for example as shown in  FIG. 2 , can be accessed using a system, for example, of the type described in the aforenoted U.S. Non-provisional patent application Ser. Nos. 11/618,619 and 12/350,609, and after gaining access to the facet joint  36 , a delivery tool  46  shown by way of example in  FIG. 3 , can have its distal end inserted into the facet joint  36  and by expanding a distraction mechanism at the distal tip of the tool  46 , the facet joint  36  can be distracted or enlarged. The distraction mechanism itself can be detachable from the tool  46  and left in the facet joint  36  as an implant or a separate implant can be inserted with the delivery tool  46  or otherwise once the joint  36  has been distracted. Accordingly, it is noted that while the tools herein are referred to as delivery tools because they may be used to deliver a distraction mechanism, the distraction mechanism may or may not be the resulting implant.  FIG. 4  shows from a lateral location an implant  48  positioned in a facet joint  36  which holds the joint  36  in a distracted condition, while  FIG. 5  is a plan view showing implants in position on facets  32  of a vertebra  34 . 
     A first embodiment of a delivery tool  59  in accordance with the present invention is shown in  FIGS. 6A-6C . It will there be seen, pursuant to the above description with any and/or all of the embodiments of the present invention to be disclosed hereafter, a delivery tool can be inserted down the working cannula, for example of the access system described previously, which can be docked in a facet joint  36 . The distal end of the delivery tool can be positioned at the anterior aspect of the joint  36  and the surgeon can apply energy to the delivery tool to create separation and distraction of the facet joint  36 . The separation can occur in both the vertical and horizontal planes of the joint  36  resulting in vertical distraction and forward/anterior translation of the superior vertebrae relative to the inferior vertebrae. The facet joint distraction and forward translation can cause an increase in foramina) area and thus reduce nerve root compression and associated symptoms. 
     Referring to the first embodiment of the invention shown in  FIGS. 6A-6C , a delivery tool  59  can include a handle  57 , a distraction cannula  52 , and a distraction mechanism  50 . The handle portion  57  can include any of the energy delivering handles described above. The handle  57  can be connected to the cannula  52  and the distraction mechanism  50  positioned within the cannula  52 . The handle  57  can be configured to actuate the distraction mechanism  50 . 
     The distraction mechanism  50  can be positioned at the tip of the delivery tool  59  and can include a band  54  of a somewhat rigid material that can be flexed so as to expand and become tall and generally flattened as it exits a rectangular opening  56  in the wall  58  of the distraction mechanism  50 . The proximal end of the band  54  can be moveable and the distal end can be restrained. The rectangular opening  56 , and thus the corresponding protruding band  54  can be smaller in length and width than the dimensions of the facet joint  36  being treated. The band  54  can be made of titanium, carbon, PEEK, nitinol, allograft, polymer, or plastic. Other elastic materials can be used. 
     In use, the handle  57  can be actuated thereby advancing the band  54 . The force on the band  54  together with the restrained distal end of the band  54  can cause the band  54  to change its shape and configuration. That is, the compression developed in the band  54  can cause it to buckle out of plane and bow upwardly through the opening  56  and allow it to flatten out or conform to surface profile of the articular surface of the superior facet. While the band  54  may be sufficiently flexible to bow under compression, it may be sufficiently rigid to apply energy or force to the contacted articular surface. This applied force can result in the distraction and forward translation of the joint  36 . 
     In one embodiment, the distraction mechanism  50 , once expanded, can be separated from the cannula  52  and remain in place as an implant to retain the expanded condition of the facet joint  36 . This may occur by way of a circumferential perforation between the cannula  52  and the distraction mechanism  50  just proximal to the opening  56 . A release latch can also be provided between the cannula  52  and the distraction mechanism  50 . Accordingly, the cannula  52  can be released from the distraction mechanism  50  and handle  57  and cannula  52  can be removed leaving the distraction mechanism  50  behind. In an alternative embodiment, a separate implant of the types to be described hereafter in other embodiments of the invention could be positioned in the distracted facet joint  36  before the distraction device was removed. 
     A second embodiment of the invention is shown in  FIGS. 7A-7C . A handle  67  and cannula  62  can be provided as described previously. In this embodiment, a distraction mechanism  60  in the form of a collapsible box can be positioned on the distal end of the delivery tool  69 . The distraction mechanism  60  can include upper  66  and lower  64  walls as well as end walls  68  with the walls  64 ,  66 ,  68  being pivotally connected so the device is movable between a flattened position as shown in  FIG. 76  to an expanded position as shown in  FIG. 7A . A locking mechanism can also be provided such as a cross-brace or other device for maintaining the mechanism  60  in an expanded position once expanded. 
     Fixation mechanisms  70  can be provided on the exterior surface of both upper  64  and lower  66  walls. These fixation mechanisms  70  can be in the form of 1) Aggressive shark teeth, 2) Cleats, and/or 3) Roughened pores. The aggressive shark teeth (as shown in  FIG. 7A ) can have a directional orientation positioned to achieve optimal fixation relative to the natural biomechanics of various sections of the spine. The teeth can be long enough to gain purchase in the cortical bone of the facet surfaces. The cleats can have a less aggressive profile than the shark teeth but still allow for directional orientation for the same reasons described above. These cleats can also be capable of anchoring in the hard cortical bone of the facet surface. The roughened pores be positioned on the surface and can be adapted to prevent free sliding of the facet joint  36 . These surfaces can be roughened and coated with FDA master file approved resurfacing chemicals that create friction and prevent device migration. 
     The collapsible box can be made of titanium, steel, carbon, PEEK, nitinol, polymer, or plastic. As with the embodiment described above, the collapsible box system can be configured to detach for permanent implantation or can be used to retain distraction of the joint  36  while an auxiliary implant or gel is positioned in the distracted joint  36 . 
     In use, the collapsible box can be inserted through the cannula of an access system as described previously to position the collapsible box within the facet joint  36 . The box can be actuated with the handle  67  of the tool causing the box to transition from a collapsed or flat parallelogram configuration to an expanded rectangular configuration. As is probably best appreciated by reference to  FIG. 7A , the collapsible box can be moved between its collapsed and expanded conditions by actuating the handle  67 , which can pull or push on an upper flexible but somewhat rigid strip  72  connected to the upper wall  64  while a lower similar strip  74  connected to the lower wall  66  holds the lower wall  66  in a fixed position. The expansion can create separation of the facet joint  36  in both the vertical and horizontal planes. As the collapsible box expands and causes distraction and translation, the fixation mechanisms  70  engage the facet surfaces securing the structure and allowing for controlled distraction and translation of the facet joint  36 . 
     A third embodiment of a delivery tool  79  in accordance with the invention is shown in  FIGS. 8A -SC and can be seen to be similar to that of the second embodiment of  FIGS. 7A-7C . In this embodiment, a distraction mechanism  76  in the form of a collapsible box is again utilized but the bottom surface of the lower wall  78  of the box has fixation mechanisms  80  for engaging the lower facet to hold the lower wall  78  of the box in a fixed position while the upper wall of the box with no such teeth is shifted relative thereto with a pair of rigid but somewhat flexible strips  84  that can be extended or retracted with the insertion handle  77  to expand or flatten the collapsible box, respectively. 
     A fourth embodiment of a delivery tool  89  in accordance with the present invention is shown in  FIGS. 9A-9C . In this embodiment of the invention, the distraction mechanism  88  can have a diamond-shaped or oblong distraction head  90  made from a somewhat rigid but flexible band or strip of material. The mechanism  88  can include an actuator in the form of an elongate member  92  extending longitudinally there through that is adapted to draw the opposing ends  94 ,  96  of the distraction head  90  together. The elongate member  92  can be a threaded member adapted to draw the ends  94 ,  96  of the head  90  together by interaction with a female member  91 . The interaction can be via a screw action with a female threaded member as shown. Alternatively, the elongate member  92  can be a toothed member adapted to draw the ends  94 ,  96  of the head  90  together via a ratcheting action with a female ratchet member similar to that of a cable tie. In either case, the elongate member  92  can extend through the head  90  of the distraction mechanism  88  and can include a stop or flange  93  on a distal end preventing the head  90  from advancing beyond the distal end of the elongate member  92 . The female member  91  can be positioned on the elongate member  92  just proximal to the head  90 . Advancing the female member  91  along the elongate member  92  via screwing action or sliding ratcheting action can compress the head  90  between the female member  91  and the flange  93  thereby causing the head  90  to expand as shown when comparing  FIG. 9B to 9C . 
     It is noted that several alternative configurations and relationships of the elongate member  92  with a female member  91  can be provided. That is, for example, one end of the head  90  can form the female member  91  such that actuation of the elongate member  92  causes the end of the head  90  with the female member  91  to wat along the elongate member  92  thereby drawing the ends  94 ,  96  of the head together. Other configurations and relationships can be provided and are within the scope of the present invention. 
     It is also noted that  FIGS. 9A-9C  depict a female member  91  in the form of a nut that is threadable over an elongate member  92  in the form of a bolt. Accordingly, the cannula  86  of the delivery tool  89  includes a distal tip in the form of a nut driver. Those of skill in the art will understand and appreciate that alternative engagements between the cannula  86  and the female member  91  or the elongate member  92  can be provided. That is, depending on the configuration, actuation may required that the female member  91  be rotated or advanced and in other configurations, the elongate member  92  may need to be rotated, advanced, or even withdrawn. In some embodiments, the engagement between the cannula  86  and the female member  91  or elongate member  92  can be, for example, a straight screw driver tip, an alien wrench type tip, or other engaging shapes. 
     The head  90  of the distraction mechanism  88  can be made out of titanium, steel, carbon, PEEK, nitinol, or plastic. Other materials can be used. The distraction mechanism  88  can be configured to detach from the delivery tool  89  as shown so that it becomes a permanent implant. Alternatively, the distraction mechanism  88  can be used only for distraction purposes so that a separate implant can be positioned in the facet joint  36  to retain the distraction while the distraction mechanism  88  is removed. In this embodiment, the cannula  86  can include a more permanent connection to the female member  91  or elongate member  92  in contrast to that depicted in  FIGS. 7B and 7C . 
     In use, energy can be applied to the flattened diamond or oblong head  90  via the handle  87  and cannula  86  assembly. The energy can cause the opposing ends  94 ,  96  of the head  90  to draw together and the head  90  can expand resulting in an increased height in the head  90 . The expansion of the head  90  can cause the surfaces of the head  90  to engage with the facet surfaces. As the head  90  expands against the facet surfaces, the joint  36  can separate in both the horizontal and vertical planes. This separation can lead to distraction and forward translation of the facet joint  36 . Moreover, the flexible nature of the head  90 , while sufficiently rigid to cause separation of the joint  36 , may also conform to the contour of the articular surfaces of the facet joint  36  thereby distributing the compressive load from the joint  36  more evenly over the surface interacting with the distraction mechanism  88 . This shape conformance can also function to resists withdrawal or dislodgement of the implant. Additionally, while not shown, the head  90  of the device can include fixation mechanisms along the surface of the head  90  adapted to engage the articular surfaces of the facet joint  36 . 
     A fifth embodiment of the distraction mechanism of the present invention is shown in  FIGS. 10A-10D . In this embodiment, pairs of pivotal teeth  100  can be mounted on a common base or central core  95 . The teeth  100  can be pivotal between a folded or retracted position as shown in  FIG. 10C  or the teeth  100  can be pivoted outwardly. Each pair of teeth  100  may be pivotal independent of the other teeth  100 . However, as in the embodiment shown, the teeth  100  may overlap in the retracted position such that when underlying teeth  100  are pivoted outwardly the overlying teeth  100  are naturally lifted. The retracted position can provide for insertion of the mechanism  98  into a facet joint  36  and the outwardly pivoted position can serve to distract the joint  36 . 
     The distraction mechanism  98  can also include an actuation device in the form of an elongate member  101  adapted to be advanced into the base or central core, where advancing the elongate member  101  can serve to actuate the teeth  100  and pivot them outwardly. As shown, the elongate member  101  can be a threaded member and the central core  95  can include thread slots positioned below the position of the retracted teeth  100  and relatively close to the pivot point of the teeth  100 . Accordingly, when threaded member is advanced into central core  95 , the threads from the threaded member can protrude through the thread slots and can engage the teeth  100  relatively close to the pivot point of the teeth  100 . The protruding thread can thus distract the teeth  100  and pivot them outward. As the threaded member is continually advanced, additional teeth  100  can be distracted thereby distracting the facet joint  36 . The close proximity of the protruding thread to the pivot point of the teeth  100  can function to minimize the distance that the thread must protrude to suitably distract the associated teeth  100 . 
     In an alternative embodiment, the elongate member  101  may be a longitudinal shaft with radiused fins positioned along two lateral sides of the shaft. Each pair of fins can be positioned to correspond to each pair of teeth  100  and the fins can be positioned longitudinally along the elongate member  101  so as to be in close proximity to the pivot point of a respective pair of teeth  100 . The elongate member  101  can be rotated causing the tins to pass beneath the teeth  100  near their respective pivot points and cause the teeth  100  to simultaneously pivot outward. 
     In still another embodiment, the elongate member  101  can be in the form of plunger type actuation device. In this embodiment, the teeth  100  may extend through the base or central core  95  via a slit in the base or central core  95 . The teeth  100  can further extend to and be pivotally connected to the elongate member  101  passing through the central core  95 . Accordingly, advancing the elongate member  101  forward or distally can cause the teeth  100  to retract due to decreasing the angle of the pivot point of the elongate member  101  relative to the slit through which it passes. Withdrawing the elongate member  101 , on the other hand, can cause the teeth  100  to pivot outwardly simultaneously thus functioning to distract the joint  36 . In this embodiment, the elongate member  101  can threadably engage the inside of the central core  95  to allow for controlled advancement and withdrawal of the elongate member  101  or the elongate member  101  can be slidably received in the central core  95 . 
     Any or all of the above described elongate members  101  can include an engagement feature at a proximal end for engagement by the cannula  105  or device positioned within the cannula  105 . The engagement feature can be adapted to provide for transferring rotational, advancing, or withdrawing forces. As shown, the engagement feature can include a straight screw driver receiving slot  103 . The engagement feature can be an alien type connection or a hex head for receiving a nut driving device, or a square head for receiving a square drive device. Those of skill in the art will understand and appreciate that several engagement features are available and are within the scope of the invention. 
     When energy is applied to the handle  97  of the tool  99 , the teeth  100  of each pair can change their orientation or expand to achieve a suitable angle relative to the central core  95 . In some embodiments this angle can range from approximately 10° to approximately 90. In other embodiments, this angle can be approximately 45°. In this embodiment, in its fully expanded state, the mechanism  98  can take on the appearance of a Christmas tree. 
     In use, the mechanism  98  can be inserted into the facet joint  36  in a flattened, collapsed state. Distraction energy can be applied to the handle  97  causing the mechanism  98  to expand which causes the multiple teeth  100  to engage both the top and bottom facet surfaces of the joint  36 . As the mechanism  98  is expanded to achieve increasingly larger dimensions, the facet joint  36  surfaces can separate. This separation in both the vertical and horizontal planes of the facet joint  36  can cause distraction and translation of the facet joint  36 . 
     A sixth embodiment of a tool  109  of the present invention is shown in  FIGS. 11A-11C . In this embodiment, the distraction mechanism  102  at the distal end of the tool  109  can have a relatively flat and ovular head  110  with a beveled tip  106  to facilitate insertion into the facet joint  36 . The mechanism  102  can have opposing relatively flat surfaces where the edges  112  interconnecting the surfaces are rounded along the lateral and medial edges of the mechanism  102 . The distraction mechanism  102  can be connected to the distal end of the cannula  107  with a rotationally resistive connection such that rotation of the cannula  107  causes rotation of the mechanism  102 . 
     In use, distraction energy can be applied to the handle  108  of the deliver tool  109  to cause rotation of the distraction mechanism  102 . As the flat head  110  of the mechanism  102  rotates, the articular surfaces of the facets can be forced apart due to a height of the mechanism (through the width of the head  110 ) being greater than its flattened dimension. The increased height achieved from rotation of the mechanism  102  can cause the flat, round surfaces of the mechanism  102  to engage the facet surfaces and separate them. This rotational distraction can result in vertical and horizontal separation of the facet joints  36  achieving distraction and forward translation of the joint  36 . 
     The distraction mechanism  102  can be mounted on the distal end of the delivery tool  109  so that it can be removed from the delivery tool  109  if desired to remain as an implant to retain the distraction of the joint  36  or can be retained in position until an auxiliary implant is positioned in the joint  36  and then removed with the delivery tool  109 . 
     A seventh embodiment of the present invention is shown in  FIGS. 12A-12D . This embodiment is similar to that of the sixth embodiment in that the mechanism  104  is rotatable to achieve distraction of the joint  36 , but rather than possibly serving as a mechanical implant, as is possible with the sixth embodiment, the mechanism  104  can be used to inject a fluid such as a hydrogel, PMMA bone cement. BMP, silicone, or the like, into the facet joint  36 . The distraction mechanism  104  can be mounted on the distal end of a delivery tool  114 , which uses a thumb slide  118  for applying energy to the mechanism  104 . The distraction mechanism  104  comprises a somewhat flattened and rigid blade  120  that is slightly S-shaped in cross-section and is hollow with the hollow interior of the mechanism  104  communicating with lateral ports  122  in notches  124  formed in the side edges of the blade  120 . When the mechanism  104  is inserted into a facet joint  36 , it is inserted with its relative flat dimension oriented generally parallel to the articular surfaces of the joint  36 . To obtain distraction, the mechanism  104  can be rotated with the delivery tool  119 , which can cause the joint  36  to distract. Once the joint  36  has been distracted, a gel or other suitable fluid can be emitted through manipulation of the thumb slide  118  on the delivery tool  119  so that the gel is forced through the hollow interior of the device and out the injection ports  122  to fill the facet joint  36  to the desired level. The distraction mechanism  104  can then be withdrawn with the gel serving as an implant to retain the distracted joint  36  at the desired separation. 
     As with the rest of the embodiments of the invention described herein, in some versions of the embodiment depicted in  FIGS. 12A-12D , the tool  119  may include a central delivery lumen through which an implant may be delivered, for example, via a plunger or push rod, to the distracted facet or joint space. In other versions of the embodiment depicted in  FIGS. 12A-12D , another delivery tool may be employed once the distraction mechanism  104  has distracted the joint  36 . 
     An eighth embodiment of the invention is shown in  FIGS. 13A-13D . In this embodiment, the distraction mechanism  126  can have a generally hollow elongated body  130 . In some embodiments, the body  130  may be relatively cone-shaped. The thickness of the body  130  can be small enough so it can be initially inserted a short distance into a relatively flat and collapsed facet joint  36 . The body  130  can include facet engaging features  132  including diametrically opposed deployable keels ( FIG. 13B ), thread slots ( FIGS. 13A and 130 ), or deployable teeth ( FIGS. 13E, 13F, and 13H ). The keels can have a retracted position wherein they lie within the confines of the body  130 , but, when activated as indicated with the arrows in  FIG. 13B , extend in a tapered manner away from the outer surface of the body  130 . The thread slots shown in  FIG. 13A  can be adapted to receive treads from an actuator that can be advanced through the body  130  to distract the facet joint  36 . The threads of the actuator can gain purchase in the articular surfaces of the facet by protruding through the thread slots of the body  130 . The deployable teeth, like the keels, can have a retracted position wherein they lie within the confines of the body  130 , but, when activated, extend through openings in the body  130  to engage the articular surfaces of the facet joint. 
     The distraction mechanism  126  can include an actuator as shown in the form of an elongate member  134 . The elongate member  134  can be a threaded member or a toothed ratchet type member adapted to be inserted through the hollow core of the body  130 . As shown in  FIGS. 13A and 138 , the elongate member  134  can be a screw or bolt type member adapted to threadably engage the body  130 . The elongate member  134  can be actuated and advanced via distraction energy applied to the tool  129  via a handle  128  as previously described. In the case of a body  130  having keels, the advancing elongate member  134  can result in the expanding keels engaging the facet surfaces of the joint  36  causing separation of the joint  36  as increasingly more distraction energy is applied resulting in progressively more deployment and height of the device with the keels also providing fixation to the facet surfaces. In the case of threaded slots, the advancement of the elongate member  134  can expand or stretch the body  130  or merely advance through the body  130 . As the threads of the elongate member  134  engage the threaded slots, the threads can protrude through the slots and cut into or otherwise engage the articular surfaces of the facet joint  36 . In the case of deployable teeth, the advancing elongate member  134  can force the teeth through openings in the body  130  thereby causing them to engage the facet surfaces of the joint  36  allowing for secured positioning of the implant. 
     As shown, the elongate member  134  can include an engagement feature  135  for receiving a corresponding engagement feature from the cannula  127  of the delivery tool. As shown the engagement feature  135  of the elongate member can be adapted to receive a straight screw driver tip. Other rotating and/or driving engagements can be provided. 
     A ninth embodiment of the invention is shown in  FIGS. 14A-14C . In this embodiment, the distraction mechanism  138  may include one or more leaf blades  142  with tapered tips  144 . The blades  142  may extend longitudinally from a delivery tool cannula  137  and may be stacked relative to one another. The blades  142  may be actuatable independent of one another and may be actuatable in consecutive order. 
     The blades  142  can be made of steel, titanium, PEEK, carbon, or nitinol. Other materials can be used. The blades  142  can be configured as temporary distraction shims or permanent detachable implants which can be left in the distracted joint  36 . If the stacked blades  142  are configured for detachment and permanent implantation, they can include one or more of the previously described fixation mechanisms. Additionally, the blades  142  can include relative motion restraints adapted to prevent relative slippage from occurring between blades  142 . These restraints can include detent recesses and protrusions or other restraints. 
     The distraction achieved with this system can occur by advancing the blades  142  one at a time into the facet joint  36  so that as an increasing thickness or height of the stack of blades  142  is inserted into the joint  36 , distraction is achieved. The number of blades  142  extended into the joint  36  can be increased until the desired distraction of the joint  36  is achieved. 
     The handle  140  of the present embodiment can include any of the handles previously described. However, as shown in  FIGS. 14B and 14C , the handle  140  can include a rotating dial type handle  140  such that rotation of the dial relative to the handle  140  causes actuation of the blades  142 . This can occur through an internal screw system that can convert radial motion to longitudinal motion. Additionally, the proximal ends of the blades can be initially staggered such that an internally advancing rod can first engage and advance the bottom blade, and then the next blade, and the next blade, and so on. Accommodations can also be made to avoid continued advancement of a given blade  142  once it enters the joint. Accordingly, incremental rotation of the dial can cause incremental advancement of the internal rod and thus consecutive advancement of blades  142 . 
     The dial can include measurements corresponding to the thickness of each of the advancing blades  142  and can thus display to the user, the total distraction being provided by the blades  142 . That is, rotation of the dial can advance a first blade  142  into the joint  36  and the indication on the dial can reflect the thickness of the first blade  142  and thus the resulting distraction. Upon further rotation of the dial, additional blades  142  can be advanced into the joint  36  and the indication on the dial can reflect the cumulative thickness of the first blade  142  and the additional blades thereby reflecting the total distraction. 
     Accordingly, the present embodiment can be used to distract a facet joint  36  as described and can also be used as an implant. However, the tool  139  can also be used to calibrate or prepare for a distraction procedure by assisting a user in determining the appropriate amount of distraction. In one embodiment, the tool  139  described can be used to obtain intra operative feedback from a patient. The tool  139  can be use to incrementally distract a joint  36  to determine how much distraction is necessary to alleviate patient symptoms. Based on feedback from the patient, an appropriately sized implant can be selected for insertion into the facet joint  36 . The current embodiment can then be used to maintain the facet joint  36  in a distracted condition for placement of the implant or other devices can be used to place the implant. 
     In one version of the embodiment depicted in  FIGS. 14A-14C , each of the blades  142  of the mechanism  138  may have a longitudinally extending slot (not shown) defined therein and positionally corresponding with the slots of the adjacent blades  142  to define an overall slot (not shown) through which an implant may be delivered, for example, via a plunger or push rod, to the distracted facet or joint  36  space. In other versions of the embodiment depicted in  FIGS. 14A-14C , another delivery device may be employed once the mechanism  138  is used to distract the facet joint  36 . 
     Referring to  FIGS. 15A-15C , a tenth embodiment of a distraction mechanism  148  of the invention is illustrated. In this embodiment, a rotatable loop  148  of rectangular configuration made of a rigid material can be pivotally mounted on the distal end of the delivery tool  149  and can carry within the loop  148  an implant of the type disclosed in the prior embodiments, or of types to be disclosed hereafter, which can be deposited or left in a distracted joint  36 . The loop  1478  can have elongated side legs  154  and relatively short end legs  156  with fixation mechanisms  158  such as teeth on both surfaces of the short legs  156  of the loop  148 . The pivotal mount between the loop  148  and the deliver tool  149  can be positioned approximately midway along the length of the side legs  154 . 
     Distraction energy can be applied to the rigid loop  148  from the handle end of the delivery tool  149  causing the trailing end of the loop  148  to rotate forwardly, as illustrated with the arrows in  FIG. 15A  (posterior to anterior). Together with the teeth on the surface of the loop  148 , the loop  148  can engage the facet surfaces to separate the joint  36 . The forward rotation of the loop  148  can distract the joint  36  and also push the superior facet slightly forward in translation relative to the inferior facet. 
     When the desired distraction and translation of the facet joint  36  is achieved, the tool  149  can deposit the implant, which is cared within the loop  148 . The implant can be carried within a hollow inside the cannula  147 , for example. The implant can be introduced into the distracted joint  36  and deposited therein prior to the mechanism  146  being removed. 
     An eleventh embodiment of a distraction mechanism  160  of the present invention is shown in  FIGS. 16A-16C . The distraction mechanism  160  can include an expandable receiving portion having upper  164  and lower  166  generally planar elements which are connected at an end with a living hinge so that the mechanism  160  can be flattened for insertion into a facet joint  36 . As shown, the upper and lower generally planar elements  164 ,  166  can be relatively triangularly shaped or trapezoidally shaped with the living hinge being positioned near the narrower end of the respective shapes. Other shapes, such as, for example, rectangular, of the planar elements  164 ,  166  can be used. The outer surface of the planar elements  164 ,  166  can include tapered keels as fixation mechanisms  170  which assist in gripping the superior and inferior facet surfaces. The keels can be provided along the edges of the planar surfaces  164 ,  166  as shown or they can be provided more centrally to the planar surfaces  164 ,  166 . The outer surface can also include threaded slots as fixation mechanisms  170  for receiving threads from an actuator being advanced into the receiving portion. The outer surface can also include teeth as fixation mechanisms  170  adapted to engage the facet surfaces. 
     An actuation device  172  can be included, as shown in  FIG. 16A , and can take the form of a wedge, an elongated member, or block-type member. In the case of a wedge actuation device, the wedge can be advanced into the receiving portion between the planar members  164 ,  166  forcing the planar members  164 ,  166  apart and distracting the joint  36 , as shown in  FIG. 16B . The fixation mechanisms  170  on the surface of the planar members  164 ,  166  can engage the facet surfaces thereby resisting any tendency for the mechanism  160  to back out of the joint  36 . 
     In the case of an elongate member, the elongate member can be advanced between the planar members  164 ,  166  forcing the planar members  164 ,  166  apart and distracting the joint  36 . As shown, the elongate member may include a tapered tip to initiate the advancement. In addition, the elongate member can include threads to facilitate advancement into the receiving portion. Moreover, where threaded slots are provided on the planar members  164 ,  166 , the threads of the elongate member can engage the threaded slots and protrude through the threaded slots. Accordingly, the threads can cut into or otherwise gain purchase in the facet surfaces to prevent any back out tendency of the mechanism  160 . 
     In the case of a block-type actuation device, the block can be advanced between the planar members  164 ,  166  forcing the planar members  164 ,  166  apart and distracting the joint  36 . The block can include a taper (not shown) at a distal end for initially engaging and separating the planar members  164 ,  166 . Alternatively or additionally, a portion of the planar members  164 ,  166  may extend outside the facet joint  36  and may be pried apart for initial insertion of the block after which the forced advancement of the block can cause separation of the facet allowing the block to be fully inserted into the receiving portion and into the facet joint  36 . Where the receiving portion includes teeth and/or keels, these fixation mechanisms  170  can be forced into the facet surfaces gaining purchase therein. 
     The receiving portion of the mechanism  160  can be carried on the distal end of a delivery tool  159  and can be inserted into the facet joint  36  in a collapsed state. One of the actuation devices  172  described can then be inserted into the receiving portion from its open trailing end to expand the receiving portion by separating the planar elements  164 ,  166  until the desired distraction of the joint  36  is achieved. This separation can lead to distraction and forward translation of the facet joint  36 . 
     As shown in  FIGS. 16A and 16B , the receiving portion can conform to the shape of the articular surfaces of the facet joint  36  as described with respect to the embodiment shown in  FIG. 9 . As such, the distraction mechanism  160  can distribute the compressive load from the joint  36  more evenly over the surface interacting with the distraction mechanism  160 . This shape conformance can also function to resists withdrawal or dislodgement of the mechanism  160  or implant. It is further noted that this shape conformance can be multidirectional and where the keels are positioned along the edges of the planar elements  164 ,  166 , the keels may facilitate folding or bending of the planar surface  164 ,  166  around the actuation device  172  allowing a fixation feature more central to the planar surface  164 ,  166  (e.g., teeth) to also engage the facet surface. 
     The distraction mechanism  160  in this embodiment can be removably or permanently mounted on the distal end of an insertion tool  159  so it can be removed from the insertion tool  159  and left in the distracted joint  36  as a permanent implant or removed from the distracted joint  36  after an auxiliary implant is positioned therein. 
     With reference to  FIGS. 17A-17C , a twelfth embodiment of the invention is illustrated. As best appreciated by reference to  FIGS. 17A and 178 , the distraction mechanism  174  can be configured like a medical capsule ( FIG. 17B ) so as to be cylindrical in configuration with rounded leading and trailing ends  176 . The mechanism  174  can be formed from two generally ovular or tear-drop shaped components with an upper component  182  having fixation mechanisms  180  on its upper surface and the lower component  186  having fixation mechanisms  180  on its lower surface. The components can be slidably related along a diagonal plane  188  of separation. 
     In use, the mechanism  174  can be inserted into the facet joint  36  with a delivery tool  169  having the mechanism  174  positioned on its distal end. As the mechanism  174  is advanced, the fixation elements  184  can grip the opposing facet surfaces causing the tear-drop components  182 ,  186  to translate along the diagonal plane  188  in one direction or the other. In one direction, of course, the implant becomes longer with a maximum height of the diameter of the capsule as seen in  FIG. 17B  while in an opposite direction the components  182 ,  186  slidably converge along the diagonal plane  188  so that the implant is cammed into a taller or thicker dimension causing more distraction of the joint  36 . The mechanism  174  can have any number or type of fixation mechanisms  180  on the top and bottom surfaces to prevent migration. 
     The opposing surfaces along the diagonal plane  188  can be somewhat smooth to prevent excessive friction while facilitating small amounts of motion along the diagonal plane  188  once the mechanism  174  is permanently fixed against the superior and inferior facet surfaces. 
     The mechanism  174  can be made of steel, titanium. PEEK, silicone, plastic, polymer, or nitinol. The mechanism  174  can be detachable to facilitate permanent implantation, but, as with the other embodiments, can be removed once an auxiliary implant is positioned upon distraction of the joint  36  with the mechanism  174 . 
     A thirteenth embodiment of a distraction mechanism  192  of the invention is shown in  FIGS. 18A and 181 . The mechanism  192  of this embodiment can include a polyethylene balloon  194  mounted at the distal end of a delivery tool. The distal end of the delivery tool within the balloon  194  can include a large conduit  198  with two separated enclosed vessels  200 ,  202  and an output port  204  on the bottom of the device communicating with an inlet vessel  200  and an intake port  206  on the top of the device communicating with a return vessel  202 . Fluid can be injected into the balloon  194  through the inlet vessel  200  and removed as desired through the return vessel  202  as shown by the directional arrows in  FIGS. 18A and 188 . 
     In use, the balloon  194  can be positioned within the facet joint  36  and the balloon  194  can be inflated through the introduction of a contrast medium fluid. Pressure within the balloon  194  can be developed through further injection of fluid and thus the pressure can cause expansion of the balloon  194  structure. The balloon  194  expansion can cause separation of the facet joint  36  resulting in distraction and forward translation of the joint  36 . 
     Once in place and expanded, as with other distraction mechanisms, the mechanism  192  can be detached from the tool and used as an implant or the mechanism  192  can be used to hold the distraction of the joint  36  while another implant is placed. Where used as implant, the balloon  194  can be filled with a bio-inert hydrogel once optimal distraction and translation of the facet joint  36  is achieved. Also, a sealing valve at the proximal aspect of the balloon  194  can be provided to prevent leaking of the hydrogel. Alternatively or additionally, the balloon  194  can be inflated with a fast-curing silicone when used as a permanent implant. 
     In another embodiment of the balloon  194  (not shown), the balloon  194  can be forked shaped having two legs and a recess therebetween in which a permanent implant of any of the types previously described, or to be later described, can be positioned. In this configuration, the balloon  194  can be inflated to achieve optimal distraction and translation, but can be removed following the successful placement and fixation of the permanent implant. 
     A fourteenth embodiment of a distraction mechanism  208  of the invention is shown in  FIGS. 19A and 196  and operates similarly to that of the thirteenth embodiment shown in  FIGS. 18A and 18B . In the fourteenth embodiment, the main conduit  210  on the distal end of the delivery tool can have a large enclosed channel  214  formed therein and a smaller enclosed channel  216  communicating with the large channel. The large channel  214  can have an extended cylindrical vessel  218  protruding beyond the end of the main conduit and a rounded tip  220  with a lateral outlet port  222  in a recess  224  formed in a side thereof. A balloon  226  can be sealed to the large vessel  210  so that fluids emitted through the outlet port  222  can fill and expand the balloon  226  to distract the facet joint  36  as with the thirteenth embodiment, and the smaller enclosed channel  216  can be used to remove fluid from the balloon  226  as desired. 
     A fifteenth embodiment of the distraction mechanism  228  of the invention is shown in  FIGS. 20A-20C . The mechanism  228  can again be mounted on the distal end of a delivery tool with the mechanism  228  being a hollow cylinder  232  having tapered diametrically opposed protruding prongs  234  at its leading end. The prongs  234  can define a recess  236  therebetween and a hollow interior of the device can communicate with an injection port  238  positioned between the prongs  234 . The tapered prongs  234  can be advanced into a facet joint  36  to spread the joint  36  apart to allow room to inject fluid through the injection port  238 . The injection port  238  can be used for communicating a stylet to the facet joint  36  or for introducing materials (including bone graft, BMP, OP1, silicone, PMMA bone cement, or hydrogel) and permanent implants to provide permanent distraction and translation. 
     A sixteenth embodiment of the distraction mechanism  240  of the invention is shown in  FIGS. 21A-21C  with this mechanism  240  again being mounted on a delivery tool. The mechanism  240  can include a pair of parallel tubular members  244  on lateral aspects of the distal tip of the delivery tool and a port  246  between the tubular members  244  communicating with the hollow interior of the delivery tool. Each tubular member  244  can have a relatively small leading end but become progressively larger as bigger tubes are telescoped over the smaller tubes. The larger tubes can cause increasing separation of the facet joint  36  resulting in distraction and forward translation. The port can facilitate the introduction of subsequent instruments, stylets, materials (including bone graft, BMP, OP1, silicone, PMMA bone cement, hydrogel) and permanent implants to provide permanent distraction and translation. 
     A seventeenth embodiment of the invention is shown in  FIGS. 22A-22D . In this embodiment, the distraction mechanism  248  is mounted on the tip of a delivery tool having dual triggers  252 ,  254  for delivering energy to the mechanism  248 . The mechanism  248 , as seen best in  FIGS. 22B-22D , can include upper and lower arms  256 ,  258  having confronting flat faces with at least the upper arm being somewhat flexible while both arms are substantially rigid. The lower arm  258  can have a rearwardly and upwardly beveled leading tip  260  and a hollow interior in communication with side ports  262  on opposite sides of the arm  258 . The upper arm  256  can have a relatively flat main body which overlies in confronting relationship the lower arm  258  with the upper arm  256  having a downwardly and forwardly inclined leg  264  which conforms with the bevel of the lower arm  258 . When the upper and lower arms  256 ,  258  are collapsed, as shown in  FIG. 22B , they lie in confronting contiguous relationship with the leading edge of the upper arm  256  being close to the elevation of the lower edge of the lower arm  258  so as to provide a thin profile for insertion into a facet joint  36 . One trigger on the delivery tool can retract the upper arm  256  so that the inclined leg  264  at the leading end thereof is cammed upwardly onto the top of the lower arm  258  by the leading beveled edge  260  of the lower arm  258 . The retraction of the upper arm  256  can separate the upper arm  256  from the lower arm  258  as shown best in  FIGS. 22C and 22D  so that when they are positioned within the facet joint  36 , a distraction of the joint  36  can be achieved. Once the joint  36  is distracted to the desired degree, the introduction of instruments, stylets, materials (including bone graft, BMP, OP1, silicone, PMMA bone cement, hydrogel) or other permanent implants of the type previously disclosed herein can be introduced through the side ports  262  with the second trigger to provide permanent distraction and translation. 
     An eighteenth embodiment of the distraction mechanism of the invention is shown in  FIGS. 23A-23D . In this embodiment of the invention, the distraction mechanism  266  can again be mounted on the distal end of a delivery tool having dual triggers  270 ,  272 . The mechanism  266  can have upper and lower blades  274 ,  276  each having forwardly tapered leading ends  278  so as to define a relatively thin leading tip resembling an elongated duckbill. The tip of the duckbill for the mechanism  266  can be thin enough or flat enough to access the facet joint  36 . Once the mechanism  266  is positioned within the facet joint  36 , a distraction energy can be applied to the mechanism  266  by pulling one trigger which causes an internal hollow cylinder  280  having a blunt leading end to advance forwardly thereby separating the upper and lower blades  274 ,  276 . The separation can cause distraction of the facet joint  36  and lateral injection ports  282  can be provided on the internal cylinder through which instruments, stylets, materials (including bone graft, BMP, OP1, silicone, PMMA bone cement, or hydrogel) can be injected into the facet joint  36  by the second trigger or other permanent implants could be introduced to provide permanent distraction and translation. 
     A nineteenth embodiment of the invention is shown in  FIGS. 24A-24D  to be similar to the eighteenth embodiment. In the nineteenth embodiment, again, upper and lower relatively rigid yet flexible blades  286 ,  288  can be provided that in a closed position are contiguous and confronting with each other. Adjacent the leading end  298  of the blades  286 ,  288  the lower blade  288  can have a transverse cylindrical recess  290  formed therein while the upper blade  286  can have a transverse cylindrical protrusion  294  which seats in the recess  290  to permit the upper and lower blades  286 ,  288  to be contiguous in the closed position. An internal cylinder  294  having lateral ports  296  at its leading end can be positioned between the blades  286 ,  288  and confined therebetween when the blades  286 ,  288  are closed so that tapered forward ends  298  of the blade can be inserted into the facet joint  36 . By pulling the first trigger on the delivery tool, the upper blade  286  can be retracted rearwardly so that the cylindrical protrusion  292  is cammed by the cylindrical recess  290  to cause the upper blade  286  to elevate relative to the lower blade  288  thereby distracting the facet joint  36 . When the facet joint  36  has been distracted, instruments, stylets, materials (including bone graft, BMP, OP1, silicone. PMMA bone cement, or hydrogel) can be injected into the facet joint  36  with the second trigger or other permanent implants of the types previously disclosed herein could be introduced to provide permanent distraction and translation. 
       FIGS. 25A-25F  disclose various embodiments of permanent implants which can be inserted into a facet joint  36 , for example, with a delivery tool of the type disclosed in the tenth embodiment or any other of the embodiments disclosed herein if such embodiments are supplemented with an integral delivery lumen and push rod configuration. Alternatively, the various embodiments of the above-described distraction mechanisms can be positioned in a facet joint  36  to retain the joint  36  in a distracted position, a translated position, or a combination distracted and translated position until a permanent implant can be positioned in the distracted joint  36  separately via a separate delivery device or tool. 
       FIG. 25A  shows a permanent implant  306  that is of wedge shape having fixation mechanisms  308  on the top and bottom surfaces comprised of teeth all directed in a common direction toward the trailing end of the implant. The wedge shape can facilitate distraction that is both normal to the facet surfaces and parallel to the facet surfaces. In other words, the wedge shape can separate the facet surfaces from each other in a direction that is perpendicular and a direction that is parallel to the facet surfaces, thus both increasing the offset distance between the facet surfaces and translating the facet surfaces relative to each other. This combination of displacement can more fully open the foramina) spaces. 
       FIG. 25B  shows another implant  310  having rounded leading and trailing ends  312  and flat upper and lower parallel surfaces  314 , again with teeth on both the upper and lower surfaces  314 , which are inclined rearwardly. 
       FIG. 25C  discloses another wedge-shaped embodiment of a permanent implant  318  where the upper surface  320  of the wedge has teeth  322  directed forwardly and outwardly along opposite lateral edges at the leading edge of the wedge while the bottom surface  324  has similar teeth  322  at the trailing end of the wedge directed rearwardly and outwardly. The oppositely oriented teeth  322  may enhance and help to maintain the translation displacement already provided by the wedge shape. 
       FIG. 25D  shows a permanent implant  326  configured similarly to  FIG. 25B  with the trailing end  328  being squared off rather than rounded and with teeth  330  across the top of the leading end directed forwardly and teeth  330  across the bottom and the trailing end directed rearwardly. The oppositely oriented teeth  330  may provide a translation displacement. 
       FIG. 25E  shows still another implant  332  of generally rectangular configuration but having a concave leading end  334  and a rounded trailing end  336 . The implant  332  has rearwardly directed fixation mechanisms  338  in the form of teeth along the upper surface on lateral sides and along the side walls. 
     Permanent implants can vary in geometry, material, and fixation mechanism. For example with respect to geometry a wedge shaped implant can provide for a greater height of the posterior aspect of the implant relative to the anterior aspect of the implant. The wedge can also provide for uniform dimensions at the lateral and medial aspects of the implant. The wedge shape may result in a translating vector force and a separating vector force that results in both subluxation and distraction, thereby increasing the foramina) space more fully as discussed in U.S. provisional patent application No. 61/059,723, filed Jun. 6, 2008, and incorporated by reference herein in its entirety. A double wedged implant can provide greater height of the posterior aspect of the implant relative to the anterior aspect of the implant in addition to greater height of the lateral aspect of the implant relative to the medial aspect of the implant (see  FIG. 25F ). Other geometrical variations can include a flat rectangular shape, an oval pill shape, a concave superior surface, a concave inferior surface, a convex superior surface, a convex inferior surface, a convex anterior surface, a concave anterior surface, a convex posterior surface, and a concave posterior surface. 
     With respect to materials, several materials can be provided including steel, PEEK, carbon, allograft, polymer, and silicone. With respect to fixation mechanisms, at least three mechanisms can be included. Aggressive shark teeth can be provided with a directional orientation positioned to achieve optimal fixation relative to the natural biomechanics of various sections of the spine. The teeth can be long enough to gain purchase in the cortical bone of the facet surfaces. Cleats can also be provided that have a less aggressive profile than the shark teeth but still allow for directional orientation for the same masons described above. These cleats can also be capable of anchoring in the hard cortical bone of the facet surface. Additionally, a roughened pore surface can be provided to prevent free sliding of the implant within the facet joint  36 . These surfaces can be roughened and coated with commercially available resurface chemicals that would create friction and prevent device migration. 
     Any or all of the implants can be adapted as fusion type implants or motion preservation type devices. Implants with varying degrees of motion preservation can also be provided. In the case of a motion preservation type implant, the implant can have fixation mechanisms on one side to enable both temporary and permanent fixation to one surface of the facet joint  36  while allowing the opposing facet surface to slide freely across the surface of the implant. The facet joint  36  can be a naturally sliding joint  36  and a distraction implant with fixation on only one side may accommodate the natural sliding of the facet. However, in some circumstances, a fusion type implant can be more suitable. In these circumstances the implant can include fixation mechanisms on both sides of the of the implant. 
       FIGS. 26A-26C  disclose a twentieth embodiment of a distraction mechanism of the invention which is somewhat similar to the embodiments of  FIGS. 22A-D  and  23 A-D. In this embodiment of the invention, upper and lower confronting bars  342 ,  344 , which are relatively rigid but have flexibility, can be retained in a delivery tool so that the leading tip  348  of the distraction mechanism  340  is of a duckbill structure with the leading tip  348  of both the upper and lower bars  342 ,  344  being beveled to form a thin leading end of the mechanism  340  which can be inserted into the facet joint  36 . The upper and lower bars  342 ,  344  can define a longitudinal channel therebetween in which a plunger  350  can be slidably disposed and reciprocally moved with a finger grip  352  on the delivery tool. Forwardly of the plunger  350 , a permanent implant  354  can be positioned within the channel between the upper and lower bars  342 ,  344  so that upon forward movement of the plunger  350 , the implant  354  can spread the upper and lower bars  342 ,  344  allowing the implant  354  to be released from the leading end  348  of the distraction mechanism  340  and be deposited in the facet joint  36 . The upper and lower bars  342 ,  344  can be biased toward each other by an elastic band  356  which passes around the upper and lower bars  342 ,  344  forwardly of the delivery tool but rearwardly of the leading tip  348  of the distraction mechanism  340 . 
     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. In particular, it is noted that several embodiments have been described with particular features. It is to be understood that the features of any given embodiment can be combined with features of other embodiments and still be within the scope of the invention. For example, the elongate member of  FIGS. 9A-9C  has been described as a toothed member adapted for a ratcheting action, while in other embodiments the elongate member has been described as a threaded member. Where functionality allows, interchanging certain features of one embodiment with another embodiment is within the scope of the present invention.