Patent Publication Number: US-6699246-B2

Title: Spine distraction implant

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation of Ser. No. 09/706,991 filed Nov. 6, 2000 now U.S. Pat. No. 6,332,883, which is a continuation of Ser. No. 09/473,173, filed Dec. 28, 1999, now U.S. Pat. No. 6,235,030, which is a continuation of Ser. No. 09/179,570, filed Oct. 27, 1998, now U.S. Pat. No. 6,048,342, which is a Continuation-in-Part of Ser. No. 09/175,645 filed Oct. 20, 1998, now U.S. Pat. No. 6,068,630, which is a Continuation-in-Part of Ser. No. 08/958,281, filed Oct. 27, 1997, now U.S. Pat. No. 5,860,977, which is a Continuation-in-Part of Ser. No. 08/778,093, filed Jan. 2, 1997, now U.S. Pat. No. 5,836,948. 
    
    
     BACKGROUND OF THE INVENTION 
     As the present society ages, it is anticipated that there will be an increase in adverse spinal conditions which are characteristic of older people. By way of example, with aging comes increases in spinal stenosis (including but not limited to central canal and lateral stenosis), the thickening of the bones which make up the spinal column and facet arthropathy. Spinal stenosis is characterized by a reduction in the available space for the passage of blood vessels and nerves. Pain associated with such stenosis can be relieved by medication and/or surgery. Of course, it is desirable to eliminate the need for major surgery for all individuals and in particular for the elderly. 
     Accordingly, there needs to be developed procedures and implants for alleviating such condition which are minimally invasive, can be tolerated by the elderly and can be performed preferably on an outpatient basis. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to providing a minimally invasive implant and method for alleviating discomfort associated with the spinal column. 
     The present invention provides for apparatus and method for relieving pain by relieving the pressure and restrictions on the aforementioned blood vessels and nerves. Such alleviation of pressure is accomplished in the present invention through the use of an implant and method which distract the spinous process of adjacent vertebra in order to alleviate the problems caused by spinal stenosis and facet arthropathy and the like. While the implant and method particularly address the needs of the elderly, the invention can be used with individuals of all ages and sizes where distraction of the spinous process would be beneficial. 
     In one aspect of the invention, an implant is provided for relieving pain comprising a device positioned between a first spinous process and a second spinous process. The device includes a spinal column extension stop and a spinal column flexion non-inhibitor. 
     In another aspect of the invention, the implant is positioned between the first spinous process and the second spinous process and includes a distraction wedge that can distract the first and second spinous processes as the implant is positioned between the spinous processes. 
     In yet another aspect of the present invention, the implant includes a device which is adapted to increasing the volume of the spinal canal and/or the neural foramen as the device is positioned between adjacent spinous processes. 
     In yet a further aspect of the present invention, a method is presented for relieving pain due to the development of, by way of example only, spinal stenosis and facet arthropathy. The method is comprised of the steps of accessing adjacent first and second spinal processes of the spinal column and distracting the processes a sufficient amount in order to increase the volume of the spinal canal in order to relieve pain. The method further includes implanting a device in order to maintain the amount of distraction required to relieve such pain. 
     In yet a further aspect of the invention, the method includes implanting a device in order to achieve the desired distraction and to maintain that distraction. 
     In yet a further aspect of the invention, the implant includes a first portion and a second portion. The portions are urged together in order to achieve the desired distraction. 
     In still a further aspect of the invention, the implant includes a distracting unit and a retaining unit. The distracting unit includes a body which can be urged between adjacent spinous processes. The body includes a slot. After the distracting unit is positioned, the retaining unit can fit into the slot of the retaining unit and be secured thereto. 
     In yet a further aspect of the invention, the implant includes a first unit with a central body. A sleeve is provided over the central body and is at least partially spaced from the central body in order to allow for deflection toward the central body. 
     In a further aspect of the invention, the implant includes a first unit having a central body with a guide and a first wing, with the first wing located at first end of the body. The guide extends from a second end of the body located distally from the first wing. The implant further includes a sleeve provided over said central body. The sleeve is at least partially spaced from the central body in order to allow for deflection of the sleeve toward the central body. The implant further includes a second wing and a device for securing the second wing to the first unit, wherein the sleeve is located between the first and second wings. 
     In yet another aspect of the invention, an implant system includes a cylindrical sleeve which is inwardly deflectable. The system further includes an insertion tool which includes an insertion guide, a central body, a stop and a handle. The guide and the stop extend from opposite sides of the central body and the handle extends from the stop. A sleeve fits over the guide and against the stop preparatory to being positioned between the two adjacent vertebrae with the insertion tool. 
     In yet a further aspect of the invention, the implant includes central body and first and second wings and a means for selectively positioning one of the first and second wings relative to the other in order to accommodate spinous processes of different sizes. 
     In yet still a further aspect of the invention, the implant includes a sleeve which is rotatable relative to the wings of the implant in order to be able to accommodate the anatomical structure of spinous processes. 
     In yet still a further aspect of the invention, the sleeve is formed from bar stock comprised of a super-elastic material. 
     Other implants and methods within the spirit and scope of the invention can be used to increase the volume of the spinal canal thereby alleviating restrictions on vessels and nerves associated therewith, and pain. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES 
     FIGS. 1 and 2 depict an embodiment of an implant of the invention which is adjustable in order to select the amount of distraction required. FIG. 1 depicts the implant in a more extended configuration than does FIG.  2 . 
     FIGS. 3 a  and  3   b  depict side and end views of a first forked and of the embodiment of FIG.  1 . 
     FIGS. 4 a  and  4   b  depict side sectioned and end views of an interbody piece of the implant of FIG.  1 . 
     FIGS. 5 a  and  5   b  depict side and end views of a second forked end of the embodiment of FIG.  1 . 
     FIGS. 6,  7 ,  8 ,  9  and  10  depict apparatus and method for another embodiment of the present invention for creating distraction between adjacent spinous processes. 
     FIGS. 11,  12  and  13  depict yet a further embodiment of the invention for creating distraction between adjacent spinous processes. 
     FIGS. 14 and 15 depict a further apparatus and method of an embodiment of the invention for creating distraction. 
     FIGS. 16,  16   a , and  17  depict yet another embodiment of the present invention. 
     FIGS. 18,  19  and  20  depict yet a further apparatus and method of the present embodiment. 
     FIGS. 21 and 22 depict still a further embodiment of the present invention. 
     FIGS. 23,  24  and  25  depict another embodiment of the present invention. 
     FIGS. 26,  27  and  28  depict another embodiment of the invention. 
     FIGS. 29 and 30 depict side elevational views of differently shaped implants of embodiments of the present invention. 
     FIGS. 31,  32  and  33  depict various implant positions of an apparatus of the present invention. 
     FIGS. 34 and 35 depict yet another apparatus and method of the present invention. 
     FIGS. 36,  37  and  38  depict three different embodiments of the present invention. 
     FIGS. 39 and 40 depict yet another apparatus and method of an embodiment of the present invention. 
     FIGS. 41,  42  and  43  depict yet further embodiments of an apparatus and method of the present invention. 
     FIG. 44 is still a further embodiment of an implant of the invention. 
     FIG. 45 is yet another depiction of an apparatus and method of the invention. 
     FIGS. 46 and 47 depict still a further apparatus and method of an embodiment of the invention. 
     FIGS. 48,  49 ,  50  and  51  depict yet a further apparatus and method of the invention. 
     FIGS. 52,  53 ,  54 ,  55   a  and  55   b  depict another apparatus and method of the invention. 
     FIGS. 56,  57  and  58  depict yet a further apparatus and method of the invention. 
     FIGS. 59 and 60 depict still a further embodiment of the invention. 
     FIG. 61 depicts another embodiment of the invention. 
     FIGS. 62 and 63 depict yet another embodiment of the present invention. 
     FIGS. 64 and 65 depict still a further embodiment of the present invention. 
     FIG. 66 depicts another embodiment of the invention. 
     FIGS. 67 and 68 depict yet another embodiment of the present invention. 
     FIGS. 69,  70 ,  71  and  71   a  depict a further embodiment of the present invention. 
     FIGS. 72 and 73 depict still another embodiment of the invention. 
     FIGS. 74,  75 ,  76 ,  77 , and  78  depict still other embodiments of the invention. 
     FIGS. 79,  80 ,  80   a ,  81 ,  82 ,  83 ,  83   a ,  84 ,  85 ,  86  and  87  depict still a further embodiment of the present invention. 
     FIGS. 88,  89 ,  90  and  91  depict yet another embodiment of the present invention. 
     FIGS. 92,  92   a ,  92   b ,  93 ,  93   a ,  93   b ,  93   c ,  93   d ,  94 ,  94   a ,  94   b ,  95 ,  95   a , and  96 , depict still a further embodiment of the present invention wherein a sleeve is provided which is capable of deflecting response to relative motion between the spinous processes. 
     FIG. 97 depicts still another embodiment of the present invention. 
     FIG. 98 depicts yet a further embodiment of the present invention. 
     FIGS. 99 and 100 depict still another embodiment of the present invention including an insertion tool. 
     FIGS. 101,  102 ,  102   a ,  103 ,  104 ,  105 ,  106 , and  107  depict still a further embodiment of the present invention. 
     FIGS. 108,  109 , and  110  depict still another embodiment of the present invention. 
     FIGS. 111,  112 ,  113 ,  114 ,  115 ,  116 , and  117  depict yet another embodiment of the present invention. 
     FIG. 118 depicts a graph showing characteristics of a preferred material usable with several of the embodiments of the present invention. 
     FIGS. 119 a  and  119   b  depict side and plan views of still a further embodiment of the present invention. 
     FIGS. 120 a  and  120   b  depict side and plan views of the second wing which can be used in conjunction with the embodiment of the invention of FIGS. 119 a  and  119   b.    
     FIGS. 121 a  and  121   b  depict side and plan views of the first wing and central body of the embodiment of the invention depicted in FIGS. 119 a  and  119   b.    
     FIGS. 122 a ,  122   b , and  122   c  depict top, side and end views of a guide which is a portion of the embodiment of the invention of FIGS. 119 a  and  119   b.    
     FIGS. 123 a  and  123   b  depict an end view and a cross-sectioned view respectfully of the sleeve of the embodiment of the invention of FIGS. 119 a  and  119   b.    
     FIGS. 124 a ,  124   b  and  124   c  depict a view of the embodiment of the invention of FIGS. 119 a  and  119   b  taken through line  124 — 124  in FIG. 119 b  shown in with the sleeve in various positions relative to a first wing. 
     FIG. 125 depicts an alternative embodiment of the invention as depicted in FIGS. 119 a  and  119   b.    
     FIG. 126 depicts yet a further alternative embodiment of the invention depicted in FIGS. 119 a  and  119   b.    
     FIG. 127 depicts yet a further embodiment of the invention as depicted in FIGS. 119 a  and  119   b.    
     FIG. 128 is still a further embodiment of the invention as depicted in FIG. 93 a.    
     FIG. 129 depicts still a further embodiment of the invention as depicted in FIGS. 119 a  and  119   b.   
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Embodiment of FIGS.  1 - 5   a ,  5   b    
     A first embodiment of the invention is shown in FIGS. 1-5 a ,  5   b . Implant  20  includes first and second forked ends  22  and  24 , each defining a saddle  26 ,  28  respectively. The forked ends  22 ,  24  are mated using an interbody piece  30 . As can be seen in FIGS. 3 a ,  3   b , the first forked end  22  includes a threaded shaft  32  which projects rearwardly from the saddle  26 . The threaded shaft  32  fits into the threaded bore  34  (FIG. 4 a ) of the interbody piece  30 . 
     The second forked end  24  (FIGS. 5 a ,  5   b ) includes a smooth cylindrical shaft  36  which can fit into the smooth bore  38  of the interbody piece  30 . 
     FIG. 1 shows the implant  20  in a fully extended position, while FIG. 2 shows the implant in an unextended position. In the unextended position, it can be seen that the threaded shaft  32  of the first forked end  22  fits inside the hollow cylindrical shaft  36  of the second forked end  24 . 
     For purposes of implantation between adjacent first and second spinous processes of the spinal column, the implant  20  is configured as shown in FIG.  2 . The first and second spinous processes are exposed using appropriate surgical techniques and thereafter, the implant  20  is positioned so that saddle  26  engages the first spinous process, and saddle  28  engages the second spinous process. At this point, the interbody piece  30  can be rotated by placing an appropriate tool or pin into the cross holes  40  and upon rotation, the saddle  26  is moved relative to the saddle  28 . Such rotation spreads apart or distracts the spinous processes with the resultant and beneficial effect of enlarging the volume of the spinal canal in order to alleviate any restrictions on blood vessels and nerves. 
     It is noted that this implant as well as the several other implants described herein act as an extension stop. That means that as the back is bent backwardly and thereby placed in extension the spacing between adjacent spinous processes cannot be reduced to a distance less than the distance between the lowest point of saddle  26  and the lowest point of saddle  28 . This implant, however, does not inhibit or in any way limit the flexion of the spinal column, wherein the spinal column is bent forward. 
     Preferably, such a device provides for distraction in the range of about 5 mm to about 15 mm. However, devices which can distract up to and above 22 mm may be used depending on the characteristics of the individual patient. 
     With all the ligaments (such as the superspinous ligament) and tissues associated with the spinous processes left intact, the implant  20  can be implanted essentially floating in position in order to gain the benefits of the aforementioned extension stop and flexion non-inhibitor. If desired, one of the saddles  26  can be laterally pinned with pin  29  to one of the spinous processes and the other saddle can be loosely associated with the other spinous processes by using a tether  31  which either pierces or surrounds the other spinous process and then is attached to the saddle in order to position the saddle relative to the spinous process. Alternatively, both saddles can be loosely tethered to the adjacent spinous process in order to allow the saddles to move relative to the spinous processes. 
     The shape of the saddles, being concave, gives the advantage of distributing the forces between the saddle and the respective spinous process. This ensures that the bone is not resorbed due to the placement of the implant  20  and that the structural integrity of the bone is maintained. 
     The implant  20  in this embodiment can be made of a number of materials, including but not limited to, stainless steel, titanium, ceramics, plastics, elastics, composite materials or any combination of the above. In addition, the modulus of elasticity of the implant can be matched to that of bone, so that the implant  20  is not too rigid. The flexibility of the implant can further be enhanced by providing additional apertures or perforations throughout the implant in addition to the holes  40  which also have the above stated purpose of allowing the interbody piece  30  to be rotated in order to expand the distance between the saddle  26 ,  28 . 
     In the present embodiment, it is understood that the spinous processes can be accessed and distracted initially using appropriate instrumentation, and that the implant  20  can be inserted and adjusted in order to maintain and achieve the desired distraction. Alternatively, the spinous process can be accessed and the implant  20  appropriately positioned. Once positioned, the length of the implant can be adjusted in order to distract the spinous processes or extend the distraction of already distracted spinous processes. Thus, the implant can be used to create a distraction or to maintain a distraction which has already been created. 
     The placement of implants such as implant  20  relative to the spinous process will be discussed hereinbelow with other embodiments. However, it is to be noted that ideally, the implant  20  would be placed close to the instantaneous axis of rotation of the spinal column so that the forces placed on the implant  20  and the forces that the implant  20  places on the spinal column are minimized. 
     Further, it is noted that during the actual process of installing or implanting the implant  20 , that the method uses the approach of extending the length of the implant  20  a first amount and then allowing the spine to creep or adjust to this distraction. Thereafter, implant  20  would be lengthened another amount, followed by a period where the spine is allowed to creep or adjust to this new level of distraction. This process could be repeated until the desired amount of distraction has been accomplished. This same method can be used with insertion tools prior to the installation of an implant. The tools can be used to obtain the desired distraction using a series of spinal distraction and spine creep periods before an implant is installed. 
     Embodiment of FIGS.  6 ,  7 ,  8 ,  9  and  10   
     The embodiment of the invention shown in the above FIGS. 6,  7 ,  8 ,  9  and  10  includes distraction or spreader tool  50  which has first and second arms  52 ,  54 . Arms  52 ,  54  are pivotal about pivot point  56  and releaseable from pivot point  56  in order to effect the implantation of implant  58 . As can be seen in FIG. 6, in cross-section, the arms  52 ,  54  are somewhat concave in order to cradle and securely hold the first spinous process  60  relative to arm  52  and the second spinous process  62  relative to arm  54 . The distraction tool  50  can be inserted through a small incision in the back of the patient in order to address the space between the first spinous process  60  and the second spinous process  62 . Once the tool  50  is appropriately positioned, the arms  52 ,  54  can be spread apart in order to distract the spinous processes. After this has occurred, an implant  58  as shown in FIGS. 8 and 9, or of a design shown in other of the embodiments of this invention, can be urged between the arms  52 ,  54  and into position between the spinous processes. After this occurs, the arms  52 ,  54  can be withdrawn from the spinous processes leaving the implant  58  in place. The implant  58  is urged into place using a tool  64  which can be secured to the implant  58  through a threaded bore  66  in the back of the implant. As can be seen in FIG. 10, the implant  58  includes saddles  68  and  70  which cradle the upper and lower spinous processes  60 ,  62  in much the same manner as the above first embodiment and also in much the same manner as the individual arms of the tool  50 . The saddles as described above tend to distribute the load between the implant and the spinous processes and also assure that the spinous process is stably seated at the lowest point of the respective saddles. 
     Embodiment of FIGS.  11 ,  12  and  13   
     Another embodiment of the apparatus and method of the invention is shown in FIGS. 11,  12  and  13 . In this embodiment, the spreader or distraction tool  80  includes first and second arms  82 ,  84  which are permanently pivoted at pivot point  86 . The arms include L-shaped ends  88 ,  90 . Through a small incision, the L-shaped ends  88 ,  90  can be inserted between the first and second spinous processes  92 ,  94 . Once positioned, the arms  82 ,  84  can be spread apart in order to distract the spinous processes. The implant  96  can then be urged between the spinous processes in order to maintain the distraction. It is noted that implant  96  includes wedged surfaces or ramps  98 ,  100 . As the implant  96  is being urged between the spinous processes, the ramps further cause the spinous processes to be distracted. Once the implant  96  is fully implanted, the full distraction is maintained by the planar surfaces  99 ,  101  located rearwardly of the ramps. It is to be understood that the cross-section of the implant  96  can be similar to that shown for implant  58  or similar to other implants in order to gain the advantages of load distribution and stability. 
     Embodiments of FIGS.  14 ,  15 ,  16 ,  16   a , and  17   
     In FIGS. 14 and 15, yet another embodiment of the invention is depicted. In this embodiment, the implant  110  includes first and second conically shaped members  112 ,  114 . Member  112  includes a male snap connector  116  and member  114  includes a female snap connector  118 . With male snap connector  116  urged into female snap connector  118 , the first member  112  is locked to the second member  114 . In this embodiment, a distraction or spreader tool  80  could be used. Once the spinous process has been spread apart, an implantation tool  120  can be used to position and snap together the implant  110 . The first member  112  of implant  110  is mounted on one arm and second member  114  is mounted on the other arm of tool  120 . The member  112 ,  114  are placed on opposite sides of the space between adjacent spinous processes. The members  112 ,  114  are urged together so that the implant  110  is locked in place between the spinous processes as shown in FIG.  15 . It is to be noted that the implant  110  can also be made more self-distracting by causing the cylindrical surface  122  to be more conical, much as surface  124  is conical, in order to hold implant  110  in place relative to the spinous processes and also to create additional distraction. 
     An alternative embodiment of the implant can be seen in FIGS. 16 and 17. This implant  130  includes first and second members  132 ,  134 . In this particular embodiment, the implants are held together using a screw (not shown) which is inserted through countersunk bore  136  and engages a threaded bore  138  of the second member  134 . Surfaces  139  are flattened (FIG. 17) in order to carry and spread the load applied thereto by the spinous processes. 
     The embodiment of implant  130  is not circular in overall outside appearance, as is the embodiment  110  of FIGS. 14 and 15. In particular, with respect to the embodiment of implant  130  of FIGS. 16 and 17, this embodiment is truncated so that the lateral side  140 ,  142  are flattened with the upper and lower sides  144 ,  146  being elongated in order to capture and create a saddle for the upper and lower spinous processes. The upper and lower sides,  144 ,  146  are rounded to provide a more anatomical implant which is compatible with the spinous processes. 
     If it is desired, and in order to assure that the first member  132  and the second member  134  are aligned, key  148  and keyway  150  are designed to mate in a particular manner. Key  148  includes at least one flattened surface, such as flattened surface  152 , which mates to an appropriately flattened surface  154  of the keyway  150 . In this manner, the first member is appropriately mated to the second member in order to form appropriate upper and lower saddles holding the implant  130  relative to the upper and lower spinous processes. 
     FIG. 16 a  depicts second member  134  in combination with a rounded nose lead-in plug  135 . Lead-in plug  135  includes a bore  137  which can fit snugly over key  148 . In this configuration, the lead-in plug  135  can be used to assist in the placement of the second member  134  between spinous processes. Once the second member  134  is appropriately positioned, the lead-in plug  135  can be removed. It is to be understood that the lead-in plug  135  can have other shapes such as pyramids and cones to assist in urging apart the spinous processes and soft tissues in order to position the second member  134 . 
     Embodiment of FIGS.  18 ,  19  and  20   
     The implant  330  as shown in FIG. 18 is comprised of first and second mating wedges  332  and  334 . In order to implant these wedges  332 ,  334 , the spinous processes are accessed from both sides and then a tool is used to push the wedges towards each other. As the wedges are urged towards each other, the wedges move relative to each other so that the combined dimension of the implant  330  located between the upper and lower spinous processes  336 ,  338  (FIG.  20 ), increases, thereby distracting the spinous processes. It is noted that the wedges  332 ,  334  include saddle  340 ,  342 , which receiving the spinous processes  336 ,  338 . These saddles have the advantages as described hereinabove. 
     The first or second wedges  332 , 334  have a mating arrangement which includes channel  344  and a; projection of  346  which can be urged into the channel in order to lock the wedges  332 ,  334  together. The channel  334  is undercut in order to keep the projection from separating therefrom. Further, as in other devices described herein, a detent can be located in one of the channel and the projection, with a complimentary recess in the other of the channel and the projection. Once these two snap together, the wedges are prevented from sliding relative to the other in the channel  344 . 
     While the above embodiment was described with respect to wedges, the wedges could also have been designed substantially as cones with all the same features and advantages. 
     Embodiments of FIGS.  21  and  22   
     The implant  370  is comprised of first and second distraction cone  372 ,  374 . These cones are made of a flexible material. The cones are positioned on either side of the spinous processes  376 ,  378  as shown in FIG.  21 . Using appropriate tool as shown hereinabove, the distraction cones  372 ,  374  are urged together. As they are urged together, the cones distract the spinous processes as shown in FIG.  22 . Once this has occurred, an appropriate screw or other type of fastening mechanism  380  can be used to maintain the position of the distraction cones  372 ,  374 . The advantage of this arrangement is that the implant  370  is self-distracting and also that the implant, being flexible, molds about the spinous processes as shown in FIG.  22 . 
     Embodiments of FIGS.  23 ,  24  and  25   
     In FIGS. 23 and 24, another embodiment of the implant  170  is depicted. This implant is guided in place using an L-shaped guide  172  which can have a concave cross-section such as the cross-section  52  of retraction tool  50  in FIG. 6 in order to cradle and guide the implant  170  in position. Preferably a small incision would be made into the back of the patient and the L-shaped guide tool  172  inserted between the adjacent spinous processes. The implant  170  would be mounted on the end of insertion tool  174  and urged into position between the spinous processes. The act of urging the implant into position could cause the spinous processes to be further distracted if that is required. Prior to the insertion of the L-shaped guide tool  172 , a distraction tool such as shown in FIG. 13 could be used to initially distract the spinous processes. 
     Implant  170  can be made of a deformable material so that it can be urged into place and so that it can somewhat conform to the shape of the upper and lower spinous processes. This deformable material would be preferably an elastic material. The advantage of such a material would be that the load forces between the implant and the spinous processes would be distributed over a much broader surface area. Further, the implant would mold itself to an irregular spinous process shape in order to locate the implant relative to spinous processes. 
     With respect to FIG. 25, this implant  176  can be inserted over a guide wire, guide tool or stylet  178 . Initially, the guide wire  178  is positioned through a small incision to the back of the patient to a position between the adjacent spinous processes. After this has occurred, the implant is threaded over the guide wire  178  and urged into position between the spinous processes. This urging can further distract the spinous processes if further distraction is required. Once the implant is in place, the guide tool  178  is removed and the incision closed. The insertion tools of FIGS. 23 and 24 can also be used if desired. 
     Embodiment of FIGS.  26 ,  27  and  28   
     The embodiment shown in FIGS. 26,  27  and  28  uses an implant similar to that depicted in FIGS. 8 and 9 with different insertion tools. As can be seen in FIG. 26, an L-shaped distraction tool  190  is similar to L-shaped distraction tool  80  (FIG.  12 ), is used to distract the first and second spinous processes  192 ,  194 . After this has occurred, an insertion tool  196  is placed between the spinous processes  192 ,  194 . Insertion tool  196  includes a handle  198  to which is mounted a square-shaped ring  200 . 
     The distraction tool  190  can be inserted through a small incision in the back in order to spread apart the spinous processes. Through the same incision which has been slightly enlarged laterally, an upper end  202  of ring  200  can be initially inserted followed by the remainder of the ring  200 . Once the ring is inserted, the ring can be rotated slightly by moving handle  198  downwardly in order to further wedge the spinous processes apart. Once this has been accomplished, an implant such as implant  204  can be inserted through the ring and properly positioned using implant handle  206 . Thereafter, the implant handle  206  and the insertion tool  196  can be removed. 
     Embodiments of FIGS.  29 ,  30 ,  31 ,  32  and  33   
     As can be seen in FIGS. 29 and 30, the implants  210 ,  212 , can have different shapes when viewed from the side. These implants are similar to the above-referenced implants  58  (FIG. 8) and  204  (FIG.  28 ). These implants have cross-sections similar to that shown in FIG. 10 which includes saddles in order to receive and hold the adjacent spinous processes. 
     As can be seen in FIGS. 31,  32  and  33 , these implants can be placed in different positions with respect to the spinous process  214 . Preferably as shown in FIG. 33, the implant  210  is placed closest to the lamina  216 . Being so positioned, the implant  210  is close to the instantaneous axis of rotation  218  of the spinal column, and the implant would experience the least forces caused by movement of the spine. Thus, theoretically, this is the optimal location for the implant. 
     As can be seen in FIGS. 31 and 32, the implant can be placed midway along the spinous process (FIG. 32) and towards the posterior aspect of the spinous process (FIG.  31 ). As positioned shown in FIG. 31, the greatest force would be placed on the implant  210  due to a combination of compression and extension of the spinal column. 
     Embodiment of FIGS.  34  and  35   
     Another embodiment of the invention is shown in FIGS. 34 and 35. In these figures, implant  220  is comprised of a plurality of individual leaves  222  which are substantially V-shaped. The leaves include interlocking indentations or detents  224 . That is, each leaf includes an indentation with a corresponding protrusion such that a protrusion of one leaf mates with an indentation of an adjacent leaf. Also associated with this embodiment is an insertion tool  226  which has a blunt end  228  which conforms to the shape of an individual leaf  222 . For insertion of this implant into the space between the spinous processes as shown in FIG. 29, the insertion tool  226  first insert a single leaf  220 . After that has occurred, the insertion tool then inserts a second leaf with the protrusion  224  of the second leaf snapping into corresponding indentation made by the protrusion  224  of the first leaf. This process would reoccur with third and subsequent leaves until the appropriate spacing between the spinous processes was built up. As can be seen in FIG. 29, the lateral edges  229  of the individual leaves  222  are slightly curved upwardly in order to form a saddle for receiving the upper and lower spinous processes. 
     Embodiments of FIGS.  36 ,  37  and  38   
     The embodiments of FIGS. 36,  37  and  38  which include implants  230 ,  232 , and  234  respectively, are designed in such a manner so the implant locks itself into position once it is properly positioned between the spinous processes. Implant  220  is essentially a series of truncated cones and includes a plurality of ever expanding steps  236 . These steps are formed by the conical bodies starting with the nose body  238  followed there behind by conical body  240 . Essentially, the implant  234  looks like a fir tree placed on its side. 
     The implant  230  is inserted laterally throughout the opening between upper and lower spinous processes. The first body  238  causes the initial distraction. Each successive conical body distracts the spinous processes a further incremental amount. When the desired distraction has been reached, the spinous processes are locked into position by steps  236 . At this point, if desired, the initial nose body  238  of the implant and other bodies  240  can be broken, snapped or sawed off if desired in order to minimize the size of the implant  230 . In order for a portion of the implant  230  to be broken or snapped off, the intersection between bodies such as body  238  and  240 , which is intersection line  242 , would be somewhat weaken weakened with the appropriate removal of material. It is noted that only the intersection lines of the initial conical bodies need to be so weakened. Thus, intersection line  244  between the bodies which remain between the spinous processes would not need to be weaker, as there would be no intention that the implant would be broken off at this point. 
     FIG. 37 shows implant  232  positioned between upper and lower spinous processes. This implant is wedge-shaped or triangular shaped in cross-sectioned and includes bore pluralities  245  and  246 . Through these bores can be placed locking pins  248  and  250 . The triangular or wedged-shaped implant can be urged laterally between and thus distract the upper and lower spinous processes. Once the appropriate distraction is reached, pins  248 ,  250  can be inserted through the appropriate bores of the bore pluralities  245  and  246  in order to lock the spinous processes in a V-shaped valley formed by pins  248 ,  250  on the one hand and the ramped surface  233 ,  235  on the other hand. 
     Turning to FIG. 38, the implant  234  has a triangular-shaped or wedge-shaped body similar to that shown in FIG.  32 . In this embodiment, tabs  252 , 254  are pivotally mounted to the body  234 . Once the implant  234  is appropriately positioned in order to distract the spinous processes to the desired amount, the tabs  252 , 254  rotate into position in order to hold the implant  234  in the appropriate position. 
     Embodiment of FIGS.  39  and  40   
     In the embodiment of FIGS. 39 and 40, cannula  258  is inserted through a small incision to a position between upper and lower spinous processes. Once the cannula is properly inserted, an implant  260  is pushed through the cannula  258  using an insertion tool  262 . The implant  260  includes a plurality of ribs or indentation  264  that assist in positioning the implant  260  relative to the upper and lower spinal processes. Once the implant  260  is in position, the cannula  258  is withdrawn so that the implant  260  comes in contact with and wedges between the spinous processes. The cannula  258  is somewhat conical in shape with the nose end  266  being somewhat smaller than the distal end  268  in order to effect the insertion of the cannula into the space between the spinous processes. 
     Further, a plurality of cannula can be used instead of one, with each cannula being slightly bigger than one before. In the method of the invention, the first smaller cannula would be inserted followed by successively larger cannula being placed over the previous smaller cannula. The smaller cannula would then be withdrawn from the center of the larger cannula. Once the largest cannula is in place, and the opening of the skin accordingly expanded, the implant, which is accommodated by only the larger cannula, is inserted through the larger cannula and into position. 
     Embodiments of FIGS.  41 ,  42  and  43   
     The precurved implant  270  in FIGS. 41 and 42, and precurved implant  272  in FIG. 43 have common introduction techniques which includes a guide wire, guide tool, or stylet  274 . For both embodiments, the guide wire  274  is appropriately positioned through the skin of the patient and into the space between the spinous processes. After this is accomplished, the implant is directed over the guide wire and into position between the spinous processes. The precurved nature of the implant assist in (1) positioning the implant through a first small incision in the patient&#39;s skin on one side of the space between two spinous processes and (2) guiding the implant toward a second small incision in the patient&#39;s skin on the other side of the space between the two spinous processes. With respect to the implant  270 , the implant includes a conical introduction nose  276  and a distal portion  278 . As the nose  276  is inserted between the spinous processes, this causes distraction of the spinous processes. Break lines  280 ,  282  are established at opposite sides of the implant  270 . Once the implant is properly positioned over the guide wire between the spinous processes, the nose portion  276  and the distal portion  278  can be broken off along the break lines, through the above two incisions, in order to leave the implant  270  in position. 
     Although only two break lines  280 ,  282  are depicted, multiple break lines can be provided on implant  270  so that the implant can continue to be fed over the guide wire  278  until the appropriate width of the implant  270  creates the desired amount of distraction. As described hereinabove, the break lines can be created by perforating or otherwise weakening the implant  270  so that the appropriate portions can be snapped or sawed off. 
     With respect to the precurved implant  272 , this implant is similar in design to the implant  230  shown in FIG.  36 . This implant  272  in FIG. 47, however, is precurved and inserted over a guide wire  274  to a position between the spinous processes. As with implant  230  in FIG. 43, once the appropriate level of this distraction has been reached and if desired, sections of the implant  272  can be broken, snapped or sawed off as described hereinabove in order to leave a portion of the implant wedged between the upper and lower spinous processes. 
     Embodiment of FIG.  44   
     A further embodiment of the invention is shown in FIG.  44 . This embodiment includes a combination insertion tool and implant  290 . The insertion tool and implant  290  is in the shape of a ring which is hinged at point  292 . The ring is formed by a first elongated and conically shaped member  294  and a second elongated and conically shaped member  296 . Members  294  and  296  terminate in points and through the use of hinge  292  are aligned and meet. Through similar incisions on both sides of the spinous processes, first member and second member are inserted through the skin of the patient and are mated together between the spinous processes. After this has occurred, the implant  290  is rotated, for example clockwise, so that increasingly widening portions of the first member  292  are used to distract the first and second spinous processes. When the appropriate level of distraction has occurred, the remainder of the ring before and after the section which is located between the spinous processes can be broken off as taught hereinabove in order to maintain the desired distraction. Alternatively, with a small enough ring, the entire ring can be left in place with the spinous processes distracted. 
     Embodiment of FIG.  45   
     In FIG. 45, the implant  300  is comprised of a plurality of rods or stylets  302  which are inserted between the upper and lower spinous processes. The rods are designed much as described hereinabove so that they may be broken, snapped or cut off. Once these are inserted and the appropriate distraction has been reached, the stylets are broken off and a segment of each stylet remains in order to maintain distraction of the spinous process. 
     Embodiment of FIGS.  46  and  47   
     Implant  310  of FIGS. 46 and 47 is comprised of a shape memory material which coils upon being released. The material is straightened out in a delivery tool  312 . The delivery tool is in position between upper and lower spinous processes  314 ,  316 . The material is then pushed through the delivery tool. As it is released from the delivery end  318  of the delivery tool, the material coils, distracting the spinous processes to the desired amount. Once this distraction has been achieved, the material is cut and the delivery tool removed. 
     Embodiments of FIGS.  48 ,  49 ,  50  and  51   
     As can be seen in FIG. 48, the implant  320  is delivered between upper and lower spinous processes  322  and  324 , by delivery tool  326 . Once the implant  320  is in place between the spinous processes, the delivery tool is given a 90° twist so that the implant goes from the orientation as shown in FIG. 49, with longest dimension substantially perpendicular to the spinous processes, to the orientation shown in FIG. 50 where the longest dimension is in line with and parallel to the spinous processes. This rotation causes the desired distraction between the spinous processes. Implant  320  includes opposed recesses  321  and  323  located at the ends thereof. Rotation of the implant  320  causes the spinous processes to become lodged in these recesses. 
     Alternatively, the insertion tool  326  can be used to insert multiple implants  320 ,  321  into the space between the spinous processes  322 ,  324  (FIG.  51 ). Multiple implants  320 ,  321  can be inserted until the appropriate amount of distraction is built up. It is to be understood in this situation that one implant would lock to another implant by use of, for example, a channel arrangement wherein a projection from one of the implants would be received into and locked into a channel of the other implant. Such a channel arrangement is depicted with respect to the other embodiment. 
     Embodiment of FIGS.  52 ,  53 ,  54 ,  55   a  and  55   b    
     The embodiment of FIGS. 52 through 55 b  is comprised of a fluid-filled dynamic distraction implant  350 . This implant includes a membrane  352  which is placed over pre-bent insertion rod  354  and then inserted through an incision on one side of the spinous process  356 . The bent insertion rod, with the implant  350  thereover, is guided between appropriate spinous processes. After this occurs, the insertion rod  354  is removed leaving the flexible implant in place. The implant  350  is then connected to a source of fluid (gas, liquid, gel and the like) and the fluid is forced into the implant causing it to expand as shown in FIG. 54, distracting the spinal processes to the desired amount. Once the desired amount of distraction has occurred, the implant  350  is closed off as is shown in FIG. 55 a . The implant  350  being flexible, can mold to the spinous processes which may be of irregular shape, thus assuring positioning. Further, implant  350  acts as a shock absorber, damping forces and stresses between the implant and the spinous processes. 
     A variety of materials can be used to make the implant and the fluid which is forced into the implant. By way of example only, viscoelastic substances such as methylcellulose, or hyaluronic acid can be used to fill the implant. Further, materials which are initially a fluid, but later solidify, can be inserted in order to cause the necessary distraction. As the materials solidify, they mold into a custom shape about the spinous processes and accordingly are held in position at least with respect to one of two adjacent spinous processes. Thus, it can be appreciated that using this embodiment and appropriate insertion tools the implant can be formed about one spinous process in such a manner that the implant stays positioned with respect to that spinous process (FIG. 55 b ). With such an embodiment, a single implant can be used as an extension stop for spinous process located on either side, without restricting flexion of the spinal column. 
     It is to be understood that many of the other implants disclosed herein can be modified so that they receive a fluid in order to establish and maintain a desired distraction much in the manner as implant  350  receives a fluid. 
     Embodiment of FIGS.  56 ,  57  and  58   
     The implant  360  as shown in FIG. 56 is comprised of a shape memory material such as a plastic or a metal. A curved introductory tool  362  is positioned between the appropriate spinous processes as described hereinabove. Once this has occurred, bore  364  of the implant is received over the tool. This act can cause the implant to straighten out. The implant is then urged into position and thereby distracts the spinous processes. When this has occurred, the insertion tool  362  is removed, allowing the implant to assume its pre-straightened configuration and is thereby secured about one of the spinous processes. Such an arrangement allows for an implant that is an extension stop and does not inhibit flexion of the spinous column. Alternatively, the implant can be temperature sensitive. That is to say that the implant would be more straightened initially, but become more curved when it was warmed by the temperature of the patient&#39;s body. 
     Embodiments of FIGS.  59  and  60   
     In this embodiment, the implant  380  is comprised of a plurality of interlocking leaves  382 . Initially, a first leaf is positioned between opposed spinous processes  384 ,  386 . Then subsequently, leafs  382  are interposed between the spinous processes until the desired distraction has been built up. The leaves are somewhat spring-like in order to absorb the shock and can somewhat conform to the spinous processes. 
     Embodiment of FIG.  61   
     The implant  390  of FIG. 61 includes the placement of shields  392 ,  394  over adjacent spinous processes  396 ,  398 . The shields are used to prevent damage to the spinous processes. These shields include apertures which receives a self-tapping screw  400 ,  402 . In practice, the shields are affixed to the spinous processes and the spinous processes are distracted in the appropriate amount. Once this has occurred, a rod  404  is used to hold the distracted position by being screwed into each of the spinous processes through the aperture in the shields using the screws as depicted in FIG.  61 . 
     Embodiment of FIGS.  62  and  63   
     Implant  410  of FIGS. 62,  63  is comprised of first and second members  412 ,  414  which can be mated together using an appropriate screw and threaded bore arrangement to form the implant  410 . Main member  412  and mating member  414  form implant  410 . Accordingly, the implant  410  would have a plurality of members  414  for use with a standardized first member  412 . FIGS. 62 and 64 show different types of mating members  414 . In FIG. 62, the mating member  414  includes projections  416  and  418  which act like shims. These projections are used to project into the space of saddles  420 ,  422  of the first member  412 . These projections  416 ,  418  can be of varying lengths in order to accommodate different sizes of spinous processes. A groove  424  is placed between the projections  416 ,  418  and mates with an extension  426  of the first member  412 . 
     As shown in FIG. 63, the projections of the embodiment shown in FIG. 62 are removed and recesses  428 ,  430  are substituted therefor. These recesses expand the area of the saddles  420 ,  422  in order to accommodate larger spinous processes. 
     Embodiment of FIGS.  64 ,  65  and  66   
     The embodiments of FIGS. 64,  65  and  66  are similar in design and concept to the embodiment of FIGS. 62 and 63. In FIG. 64, the implant  500  includes the first and second members  502 ,  504 . These members can be secured together with appropriate screws or other fastening means as taught in other embodiments. Implant  500  includes first and second saddles  506 ,  508  which are formed between the ends of first and second members  502 ,  504 . These saddles  506 ,  508  are used to receive and cradle the adjacent spinous processes. As can be seen in FIG. 64, each saddle  506 ,  508  is defined by a single projection or leg  510 ,  512 , which extends from the appropriate first and second members  502 ,  504 . Unlike the embodiment found in FIGS. 62 and 63, each of the saddles is defined by only a single leg as the ligaments and other tissues associated with the spinous processes can be used to ensure that the implant is held in an appropriate position. With the configuration of FIG. 64, it is easier to position the implant relative to the spinous processes as each saddle is defined by only a single leg and thus the first and second members can be more easily worked into position between the various tissues. 
     In the embodiment of FIG. 65, the implant  520  is comprised of a single piece having saddles  522  and  524 . The saddles are defined by a single leg  526 ,  528  respectively. In order for this implant  520  to be positioned between the spinous processes, an incision is made between lateral sides of adjacent spinous processes. The single leg  526  is directed through the incision to a position adjacent to an opposite lateral side of the spinous process with the spinous process cradled in the saddle  522 . The spinous processes are then urged apart until saddle  524  can be pivoted into position into engagement with the other spinous process in order to maintain the distraction between the two adjacent spinous processes. 
     The embodiment of FIG. 66 is similar to that of FIG. 65 with an implant  530  and first and second saddles  532  and  534 . Associated with each saddle is a tether  536 ,  538  respectively. The tethers are made of flexible materials known in the trade and industry and are positioned through bores in the implant  530 . Once appropriately positioned, the tethers can be tied off. It is to be understood that the tethers are not meant to be used to immobilize one spinous process relative to the other, but are used to guide motion of the spinous processes relative to each other so that the implant  530  can be used as an extension stop and a flexion non-inhibitor. In other words, the saddles  532 ,  534  are used to stop spinal column backward bending and extension. However, the tethers do not inhibit forward bending and spinal column flexion. 
     Embodiments of FIGS.  67 ,  68   
     The implant  550  is Z-shaped and includes a central body  552  and first and second arms  554 ,  556 , extending in opposite directions therefrom. The central body  552  of the implant  550  includes first and second saddles  558  and  560 . The first and second saddles  558  and  560  would receive upper and lower spinous processes  562 ,  568 . The arms  554 ,  556  are accordingly located adjacent the distal end  566  (FIG. 68) of the central body  552 . The first and second arms  554 , 556 , act to inhibit forward movement, migration or slippage of the implant  550  toward the spinal canal and keep the implant in place relative to the first and second spinal processes. This prevents the implant from pressing down on the ligamentum flavum and the dura. In a preferred embodiment, the central body would have a height of about 10 mm with each of the arms  554 ,  556  having a height of also about 10 mm. Depending on the patient, the height of the body could vary from about less than 10 mm to about greater than 24 mm. As can be seen in FIGS. 67 and 68, the first and second arms  554 ,  556  are additionally contoured in order to accept the upper and lower spinous processes  556 ,  558 . In particular, the arms  554 ,  556  as can be seen with respect to arm  554  have a slightly outwardly bowed portion  568  (FIG. 68) with a distal end  570  which is slightly inwardly bowed. This configuration allows the arm to fit about the spinous process with the distal end  570  somewhat urged against the spinous process in order to guide the motion of the spinous process relative to the implant. These arms  554 ,  556  could if desired to be made more flexible than the central body  552  by making arms  554 , 556  thin and/or with perforations, and/or other material different than that of the central body  550 . As with the last embodiment, this embodiment can be urged into position between adjacent spinous processes by directing an arm into a lateral incision so that the central body  552  can be finally positioned between spinous processes. 
     Embodiment of FIGS.  69 ,  70 ,  71  and  71   a    
     FIGS. 69,  70  and  71  are perspective front, end, and side views of implant  580  of the invention. This implant includes a central body  582  which has first and second saddles  584 ,  586  for receiving adjacent spinous processes. Additionally, the implant  580  includes first and second arms  588  and  590 . The arms, as with the past embodiment, prevent forward migration or slippage of the implant toward the spinal canal. First arm  588  projects outwardly from the first saddle  584  and second arm  590  projects outwardly from the second saddle  586 . In a preferred embodiment, the first arm  588  is located adjacent to the distal end  600  of the central body  582  and proceeds only partly along the length of the central body  582 . The first arm  588  is substantially perpendicular to the central body as shown in FIG.  70 . Further, the first arm  588 , as well as the second arm  590 , is anatomically rounded. 
     The second arm  590 , projecting from second saddle  586 , is located somewhat rearward of the distal end  600 , and extends partially along the length of the central body  582 . The second arm  590  projects at a compound angle from the central body  582 . As can be seen in FIGS. 70 and 71, the second arm  590  is shown to be at about an angle of 45° from the saddle  586  (FIG.  70 ). Additionally, the second arm  590  is at an angle of about 45° relative to the length of the central body  580  as shown in FIG.  71 . It is to be understood that other compound angles are within the spirit and scope of the invention as claimed. 
     In a preferred embodiment, the first and second arms  588 ,  590  have a length which is about the same as the width of the central body  582 . Preferably, the length of each arm is about 10 mm and the width of the central body is about 10 mm. However, the bodies with the widths of 24 mm and greater are within the spirit and scope of the invention, along with first and second arms ranging from about 10 mm to greater than about 24 mm. Further, it is contemplated that the embodiment could include a central body having a width of about or greater than 24 mm with arms being at about 10 mm. 
     It is to be understood that the embodiment of FIGS. 69,  70  and  71  as well as the embodiment of FIGS. 67 and 68 are designed to preferably be positioned between the L4-L5 and the L5-S1 vertebral pairs. The embodiment of FIGS. 69,  70 ,  71  is particularly designed for the L5-S1 position with the arms being designed to conform to the sloping surfaces found therebetween. The first and second arms are thus contoured so that they lie flat against the lamina of the vertebra which has a slight angle. 
     The embodiment of FIGS. 69,  70 , and  71  as with the embodiment of FIGS. 67 and 68 is Z-shaped in configuration so that it may be inserted from one lateral side to a position between adjacent spinous processes. A first arm, followed by the central body, is guided through the space between the spinous processes. Such an arrangement only requires that a incision on one side of the spinous process be made in order to successfully implant the device between the two spinous processes. 
     The implant  610  of FIG. 71 a  is similar to that immediately above with the first arm  612  located on the same side of the implant as the second arm  614 . The first and second saddle  616 ,  618  are slightly modified in that distal portion  620 ,  622  are somewhat flattened from the normal saddle shape in order to allow the implant to be positioned between the spinous processes from one side. Once in position, the ligaments and tissues associated with the spinous processes would hold the implant into position. Tethers also could be used if desired. 
     Embodiment of FIGS.  72 ,  73   
     Implant  630  is also designed so that it can be inserted from one side of adjacent spinous processes. This insert  630  includes a central body  632  with the first and second arms  634 ,  636  extending on either side thereof. As can be seen in FIG. 72, a plunger  638  is positioned to extend from an end of the central body  632 . As shown in FIG. 72, the plunger  638  is fully extended and as shown in FIG. 73, the plunger  638  is received within the central body  632  of the implant  630 . With the plunger received into the implant  632 , the third and fourth arms or hooks  640 ,  642  can extend outwardly from the central body  632 . The third and fourth arms or hooks  640 ,  642  can be comprised of a variety of materials, such as for example, shape memory metal materials or materials which have a springy quality. 
     For purposes of positioning the implant  630  between adjacent spinous processes, the plunger  638  is pulled outwardly as shown in FIG.  72 . The central body  632  is then positioned between adjacent spinous processes and the plunger  638  is allowed to move to the position of FIG. 73 so that the third and fourth arms  640 ,  642  can project outwardly from the central body  632  in order to hold the implant  630  in position between the spinous processes. 
     Plunger  638  can be spring biased to the position as shown in FIG. 73 or can include detents or other mechanisms which lock it into that position. Further, the third and fourth arms themselves, as deployed, can keep the plunger in the position as shown in FIG.  73 . 
     Embodiments of FIGS.  74 ,  75 ,  76 ,  77 , and  78   
     Other embodiments of the invention are shown in FIGS. 74 through 78. FIGS. 74,  75  and  76  disclose implant  700 . Implant  700  is particularly suited for implantation between the L4-L5 and L5-S1 vertebra. As can be seen in FIG. 74, the implant  700  includes a central body  702  which has a bore  704  provided therein. Bore  704  is used in order to adjust the modulus of elasticity of the implant so that it is preferably approximately two times the anatomical load placed on the vertebra in extension. In other words, the implant  700  is approximately two times stiffer than the normal load placed on the implant. Such an arrangement is made in order to ensure that the implant is somewhat flexible in order to reduce potential resorption of the bone adjacent to the implant. Other modulus values can be used and be within the spirit of the invention. 
     Implant  700  includes first and second saddle  706 ,  708  which are used to receive and spread the load from the upper and lower spinous processes. The saddle  706  is defined by first and second arms  710  and  712 . The second saddle  708  is defined by third and fourth arms  714  and  716 . As can be seen in FIG. 74, the first arm  710 , in a preferred embodiment, is approximately two times the length of the body  702  with the second arm being approximately less than a quarter length of the body. Third arm  714  is approximately one times the length of the body  702  with the fourth arm  716  being, in this preferred embodiment, approximately one and a half times the length of the body  702 . The arms are designed in such a way that the implant (1) can be easily and conveniently inserted between the adjacent spinous processes, (2) will not migrate forwardly toward the spinal canal, and (3) will hold its position through flexion and extension as well as lateral bending of the spinal column. 
     First arm  710  is in addition designed to accommodate the shape of the vertebra. As can be seen in FIG. 74, the first arm  710  becomes narrower as it extends away from the body  702 . The first arm  710  includes a sloping portion  718  followed by a small recess  720  ending in a rounded portion  722  adjacent to the end  724 . This design is provided to accommodate the anatomical form of for example the L4 vertebra. It is to be understood that these vertebra have a number of surfaces at roughly 30° angles and that the sloping surfaces of this embodiment and the embodiments shown in FIGS. 77 and 78 are designed to accommodate these surfaces. These embodiments can be further modified in order to accommodate other angles and shapes. 
     The second arm  712  is small so that it is easy to insert between the spinous processes, yet still define the saddle  706 . The fourth arm  716  is larger than the third arm  714 , both of which are smaller than the first arm  710 . The third and fourth arms are designed so that they define the saddle  706 , guide the spinous processes relative to the implant  700  during movement of the spinal column, and yet are of a size which makes the implant easy to position between the spinous processes. 
     The procedure, by way of example only, for implanting the implant  700  can be to make an incision laterally between two spinous processes and then initially insert first arm  710  between the spinous processes. The implant and/or appropriate tools would be used to distract the spinous processes allowing the third leg  714  and the central body  702  to fit through the space between the spinous processes. The third leg  714  would then come to rest adjacent the lower spinous processes on the opposite side with the spinous processes resting in the first and second saddle  706 ,  708 . The longer fourth leg  716  would then assist in the positioning of the implant  700 . 
     FIG. 77 includes an implant  740  which is similar to implant  700  and thus has similar numbering. The saddle  706 ,  708  of implant  740  have been cantered or sloped in order to accommodate the bone structure between, byway of example, the L4-L5 and the L5-S1 vertebra. As indicated above, the vertebra in this area have a number of sloping surfaces in the range of about 300. Accordingly, saddle  706  is sloped at less than 300 and preferably about 20 while saddle  708  is sloped at about 300 and preferably more than 300. 
     The implant  760  as shown in FIG. 78 is similar to implant  700  in FIG.  74  and is similarly numbered. Implant  760  includes third and fourth legs  714 ,  716  which have sloping portions  762 ,  764  which slope toward ends  766 ,  768  of third and fourth arm  714 ,  716  respectively. The sloping portions accommodate the form of the lower vertebra against which they are positioned. In the preferred embodiment, the sloping portions are of about 30°. However, it is to be understood that sloping portions which are substantially greater and substantially less than 30° can be included and be within the spirit and scope of the invention. 
     Embodiment of FIGS.  79 ,  80 ,  80   a ,  81 ,  82 ,  83 ,  83   a ,  84 ,  85 ,  86  and  87   
     Another embodiment of the invention is shown in FIGS. 79-87 and includes implant  800  (FIG.  86 ). Implant  800  includes a distracting unit  802  which is shown in left side, plan, and right side views of FIGS. 79,  80  and  81 . A perspective view of the distraction unit is shown in FIG.  84 . The distracting unit as can be seen in FIG. 80 includes a distracting body  804 , with longitudinal axis  805 , which body  804  has a groove  806  and a rounded or bulbous end  808  which assist in the placement of the distracting body between adjacent spinous process so that an appropriate amount of distraction can be accomplished. Extending from the distracting body  804  is a first wing  810  which in FIG. 80 is substantially perpendicular to the distracting body  804 . Such wings which are not perpendicular to the body are within the spirit and scope of the invention. First wing  810  includes a upper portion  812  and a lower portion  814 . The upper portion  810  (FIG. 79) includes a rounded end  816  and a small recess  818 . The rounded end  816  and the small recess  818  in the preferred embodiment are designed to accommodate the anatomical form or contour of the L4 (for a L4-L5 placement) or L5 (for a L5-S1 placement) superior lamina of the vertebra. It is to be understood that the same shape or variations of this shape can be used to accommodate other lamina of any vertebra. The lower portion  814  is also rounded in order to accommodate in the preferred embodiment in order to accommodate the vertebrae. The distracting unit further includes a threaded bore  820  which in this embodiment accepts a set screw  822  (FIG. 86) in order to hold a second wing  824  (FIGS. 82,  83 ) in position as will be discussed hereinbelow. 
     The threaded bore  820  in this embodiment slopes at approximately 45° angle and intersects the slot  806 . With the second wing  824  in position, the set screw  822  when it is positioned in the threaded bore  820  can engage and hold the second wing  824  in position in the slot  806 . 
     Turning to FIGS. 82,  83  and  85 , left side, plan and perspective views of the second wing  824  are depicted. The second wing  824  is similar in design to the first wing. The second wing includes an upper portion  826  and a lower portion  828 . The upper portion includes a rounded end  830  and a small recess  832 . In addition, the second wing  824  includes a slot  834  which mates with the slot  806  of the distracting unit  802 . The second wing  824  is the retaining unit of the present embodiment. 
     As can be seen in FIGS. 83 and 86, the second wing or retaining unit  824  includes the upper portion  826  having a first width “a” and the lower portion  828  having a second width “b”. In the preferred embodiment, the second width “b” is larger than first width “a” due to the anatomical form or contour of the L4-L5 or L5-S1 laminae. As can be seen in FIG. 83 a  in second wing or retaining unit  824 , the widths “a” and “b” would be increased in order to, as described hereinbelow, accommodate spinous processes and other anatomical forms or contours which are of different dimensions. Further, as appropriate, width “a” can be larger than width “b”. Thus, as will be described more fully hereinbelow, the implant can include a universally-shaped distracting unit  802  with a plurality of retaining units  824 , with each of the retaining units having different widths “a” and “b”. During surgery, the appropriately sized retaining unit  824 , width with the appropriate dimensions “a” and “b” can be selected to match to the anatomical form of the patient. 
     FIG. 86 depicts an assembled implant  800  positioned adjacent to upper and lower laminae  836 ,  838  (which are shown in dotted lines) of the upper and lower vertebrae. The vertebrae  836 ,  838  are essentially below the implant  800  as shown in FIG.  86 . Extending upwardly from the vertebrae  836 ,  838 , and between the first and second wings  810 ,  824 , are the upper and lower spinous processes  840 ,  842 . It is to be understood that in a preferred embodiment, the fit of the implant between the spinous processes can be such that the wings do not touch the spinous processes, as shown in FIG. 86, and be within the spirit and scope of the invention. 
     The implant  800  includes, as assembled, an upper saddle  844  and the lower saddle  846 . The upper saddle  844  has an upper width identified by the dimension “UW”. The lower saddle  846  has a lower width identified by the dimension “LW”. In a preferred embodiment, the upper width is greater than the lower width. In other embodiments, the “UW” can be smaller than the “LW” depending on the anatomical requirements. The height between the upper and lower saddles  844 ,  846  is identified by the letter “h”. These dimensions are carried over into FIG. 87 which is a schematic representation of the substantially trapezoidal shape which is formed between the upper and lower saddles. The table below gives sets of dimensions for the upper width, lower width, and height as shown in FIG.  87 . This table includes dimensions for some variations of this embodiment. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 
               
               
                   
                   
               
               
                   
                 Variation 
                 1 
                 2 
                 3 
               
               
                   
                   
               
             
            
               
                   
                 Upper Width 
                  8 
                 7 
                 6 
               
               
                   
                 Lower Width 
                  7 
                 6 
                 5 
               
               
                   
                 Height 
                 10 
                 9 
                 8 
               
               
                   
                   
               
            
           
         
       
     
     For the above table, all dimensions are given in millimeters. 
     For purposes of surgical implantation of the implant  800  into a patient, the patient is preferably positioned on his side (arrow  841  points up from an operating table) and placed in a flexed (tucked) position in order to distract the upper and lower vertebrae. 
     In a preferred procedure, a small incision is made on the midline of the spinous processes. The spinous processes are spread apart or distracted with a spreader. The incision is spread downwardly toward the table, and the distracting unit  802  is preferably inserted upwardly between the spinous processes  840  and  842  in a manner that maintains the distraction of spinous processes. The distracting unit  802  is urged upwardly until the distracting or bulbous end  808  and the slot  806  are visible on the other wide side of the spinous process. Once this is visible, the incision is spread upwardly away from the table and the retaining unit or second wing  824  is inserted into the slot  806  and the screw  822  is used to secure the second wing in position. After this had has occurred, the incisions can be closed. 
     An alternative surgical approach requires that small incisions be made on either side of the space located between the spinous processes. The spinous processes are spread apart or distracted using a spreader placed through the upper incision. From the lower incision, the distracting unit  802  is preferably inserted upwardly between the spinous processes  840  and  842  in a manner that urges the spinous processes apart. The distracting unit  802  is urged upwardly until the distracting or bulbous end  808  and the slot  806  are visible through the second small incision in the patient&#39;s back. Once this is visible, the retaining unit or second wing  824  is inserted into the slot  806  and the screw  822  is used to secure the second wing in position. After this has occurred, the incisions can be closed. 
     The advantage of either of the above present surgical procedures is that a surgeon is able to observe the entire operation, where he can look directly down onto the spinous processes as opposed to having to view the procedure from positions which are to the right and to the left of the spinous processes. Generally, the incision is as small as possible and the surgeon is working in a bloody and slippery environment. Thus, an implant that can be positioned directly in front of a surgeon is easier to insert and assemble than an implant which requires the surgeon to shift from side to side. Accordingly, a top-down approach, as an approach along a position to anterior line is preferred so that all aspects of the implantation procedure are fully visible to the surgeon at all times. This aides in the efficient location of (i) the distracting unit between the spinous processes, (ii) the retaining unit in the distracting unit, and (iii) finally the set screw in the distracting unit. 
     FIG. 80 a  shows an alternative embodiment of the distracting unit  802   a . This distracting unit  802   a  is similar to distracting unit  802  in FIG. 80 with the exception that the bulbous end  808   a  is removable from the rest of the distracting body  804   a  as it is screwed into the threaded bore  809 . The bulbous end  808   a  is removed once the distracting unit  802   a  is positioned in the patient in accordance with the description associated with FIG.  86 . The bulbous end  808   a  can extend past the threaded bore  820  by about 1 cm in a preferred embodiment. 
     Embodiment of FIGS.  88 ,  89 ,  90  and  91   
     Another embodiment of the invention is shown in FIGS. 88,  89 ,  90  and  91 . In this embodiment, the implant is identified by the number  900 . Other elements of implant  900  which are similar to implant  800  are similarly numbered but in the 900 series. For example, the distracting unit is identified by the number  902  and this is in parallel with the distracting unit  802  of the implant  800 . The distracting body is identified by the number  904  in parallel with the distracting body  804  of the implant  800 . Focusing on FIG. 90, the distracting unit  902  is depicted in a perspective view. The distracting unit includes slot  906  which is wider at the top than at the bottom. The reason for this is that the wider upper portion of the slot  906 , which is wider than the second wing  924  (FIG.  89 ), is used to allow the surgeon to easily place the second wing  924  into the slot  906  and allow the wedge-shaped slot  906  to guide the second wing  924  to its final resting position. As can be see in FIG. 91, in the final resting position, the largest portion of the slot  906  is not completely filled by the second wing  924 . 
     The end  908  of implant  900  is different in that it is more pointed, having sides  909  and  911  which are provided at about 45° angles (other angles, such as by way of example only, from about 30° to about 60° are within the spirit of the invention), with a small flat tip  913  so that the body  904  can be more easily urged between the spinous processes. 
     The distracting unit  902  further includes a tongue-shaped recess  919  which extends from the slot  906 . Located in the tongue-shaped recess is a threaded bore  920 . 
     As can be seen in FIG. 89, a second wing  924  includes a tongue  948  which extends substantially perpendicular thereto and between the upper and lower portions  926 ,  928 . The tab  948  includes a bore  950 . With the second wing  924  positioned in the slot  906  of the distracting unit  902  and tab  948  positioned in recess  919 , a threaded set screw  922  can be positioned through the bore  950  and engage the threaded bore  920  in order to secure the second wing or retaining unit  924  to the distracting unit  902 . The embodiment  900  is implanted in the same manner as embodiment  800  previously described. In addition, as the bore  922  is substantially perpendicular to the distracting body  904  (and not provided at an acute angle thereto), the surgeon can even more easily secure the screw in place from a position directly behind the spinous processes. 
     Embodiment of FIGS.  92 ,  92   a ,  92   b ,  93 ,  93   a ,  93   b ,  93   c ,  93   d ,  94 ,  94   a    94   b ,  95 ,  95   a , and  96   
     Still a further embodiment of the invention is depicted in FIGS. 92, and  92   a . In this embodiment, the implant  1000  as can be seen in FIG. 92 a  includes a central elongated body  1002  which has positioned at one end thereof a first wing  1004 . Wing  1004  is similar to the first wing previously described with respect to the embodiment of FIG.  88 . Bolt  1006  secures wing  1004  to body  1002  in this embodiment. Bolt  1006  is received in a bore of the body  1002  which is along the longitudinal axis  1008  of the body. It is to be understood that in this embodiment, the first unit is defined by the central body  1002 , the first wing  1004 , and the guide  1010 . 
     Alternatively, the first wing can be secured to the central body with a press fit and detent arrangement as seen in FIG. 93 c . In this arrangement, the first wing has a protrusion  1040  extending preferably about perpendicularly from the first wing, with a flexible catch  1042 . The protrusion and flexible catch are press fit into a bore  1044  of the central body with the catch received in a detent  1046 . 
     In yet another alternative embodiment, the first wing can be designed as shown in FIG. 93 d  with the protrusion directed substantially parallel to the first wing from a member that joins the first wing to the protrusion. Thus in this embodiment, the first wing is inserted into the body along the same direction as the second wing is inserted. 
     Positioned at the other end of the central body  1002  is a guide  1010 . In this particular embodiment, guide  1010  is essentially triangularly-shaped so as to be a pointed and arrow-shaped guide. Alternatively, guide  1010  could be in the shape of a cone with lateral truncated sides along the longitudinal axis  1008 . Guide  1010  includes a recess  1012  having a threaded bore  1014 . Recess  1012  is for receiving a second wing  1032  as will be described hereinbelow. 
     Additionally, it is also to be understood that the guide  1010  can be bulbous, cone-shaped, pointed, arrow-shaped, and the like, in order to assist in the insertion of the implant  1000  between adjacent spinous processes. It is advantageous that the insertion technique disturb as little of the bone and surrounding tissue or ligaments as possible in order to (1) reduce trauma to the site and facilitate early healing, and (2) not destabilize the normal anatomy. It is to be noted that with the present embodiment, there is no requirement to remove any of the bone of the spinous processes and depending on the anatomy of the patient, there may be no requirement to remove or sever ligaments and tissues immediately associated with the spinous processes. 
     The implant  1000  further includes a sleeve  1016  which fits around and is at least partially spaced from the central body  1002 . As will be explained in greater detail below, while the implant may be comprised of a bio-compatible material such as titanium, the sleeve is comprised preferably of a super-elastic material which is by way of example only, a nickel titanium material (NiTi), which has properties which allow it to withstand repeated deflection without fatigue, while returning to its original shape. The sleeve could be made of other materials, such as for example titanium, but these materials do not have the advantages of a super-elastic material. 
     FIG. 93 a  is a cross-section through the implant  1000  depicting the central body  1002  and the sleeve  1016 . As can be seen from the cross-section of FIG. 93 a  in a preferred embodiment, both the central body  1002  and the sleeve  1016  are substantially cylindrical and oval or ecliptically-shaped. An oval or elliptical shape allows more of the spinous process to be supported by the sleeve, thereby distributing the load between the bone and the sleeve more evenly. This reduces the possibility of fracture to the bone or bone resorption. Additionally, an oval or elliptical shape enhances the flexibility of the sleeve as the major axis of the sleeve, as described below, is parallel to the longitudinal direction of the spinous process. However, other shapes such as round cross-sections can come within the spirit and scope of the invention. 
     In this particular embodiment, the central body  1002  includes elongated grooves  1018 , along axis  1008 , which receives elongated spokes  1020  extending from the internal surface of the cylinder  1016 . 
     In a preferred embodiment, both the cross-section of the central body and the sleeve have a major dimension along axis  1022  and a minor dimensional along axis  1024  (FIG. 93 a ). The spokes  1020  are along the major dimension so that along the minor dimension, the sleeve  1016  can have its maximum inflection relative to the central body  1002 . It is to be understood that the central body along the minor dimension  1024  can have multiple sizes and can, for example, be reduced in thickness in order to increase the ability of the sleeve  1016  to be deflected in the direction of the central body  1002 . 
     Alternatively as can be seen in FIG. 93 b , the central body  1002  can include the spokes  1020  and the sleeve  1016  can be designed to include the grooves  1018  in order to appropriately space the sleeve  1016  from the central body  1002 . 
     In other embodiments, the sleeve can have minor and major dimensions as follows: 
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                 Minor Dimension 
                 Major Dimension 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                  6 mm 
                   
                 10 
                 mm 
               
               
                   
                  8 mm 
                   
                 10.75 
                 mm 
               
               
                   
                 12 mm 
                   
                 14 
                 mm 
               
               
                   
                  6 mm 
                   
                 12.5 
                 mm 
               
               
                   
                  8 mm 
                   
                 12.5 
                 mm 
               
               
                   
                 10 mm 
                   
                 12.5 
                 mm 
               
               
                   
                   
               
            
           
         
       
     
     In one preferred embodiment, said sleeve has a cross-section with a major dimension and a minor dimension and said major dimension is greater than said minor dimension and less than about two times said minor dimension. In said embodiment, said guide has a cross-section which is adjacent to said sleeve with a guide major dimension about equal to said sleeve major dimension and a guide minor dimension about equal to said sleeve minor dimension. Further in said embodiment, said guide extends from said central body with a cross-section which reduces in size in a direction away from said central body. 
     In another preferred embodiment, said guide is cone-shaped with a base located adjacent to said sleeve. Further, said guide has a base cross-section about the same as the oval cross-section of said sleeve. 
     Thus, from the above, it is evident that preferably a major dimension of the sleeve correspond with a major dimension of the central body and a minor dimension of the sleeve corresponds with a minor dimension of the central body. Additionally, it is evident that the major dimension of the sleeve  1016  is substantially perpendicular to a major dimension of the first wing  1004  along longitudinal axis  1030  (FIG. 92 a ). This is so that as discussed above, when the implant  1000  is properly positioned between the spinous processes, a major portion of the sleeve comes in contact with both the upper and lower spinous processes in order to distribute the load of the spinous processes on the sleeve  1016  during spinal column extension. 
     As indicated above, the preferred material for the sleeve  1016  is a super-elastic material and more preferably one comprised of an alloy of nickel and titanium. Such materials are available under the trademark Nitinol. Other super-elastic materials can be used as long as they are bio-compatible and have the same general characteristics of super-elastic materials. In this particular embodiment, a preferred super-elastic material is made up of the following composition of nickel, titanium, carbon, and other materials as follows: 
     
       
         
           
               
               
               
               
             
               
                   
                   
               
             
            
               
                   
                 Nickel 
                 55.80% 
                 by weight 
               
               
                   
                 Titanium 
                 44.07% 
                 by weight 
               
               
                   
                 Carbon 
                 &lt;0.5% 
                 by weight 
               
               
                   
                 Oxygen 
                 &lt;0.5% 
                 by weight 
               
               
                   
                   
               
            
           
         
       
     
     In particular, this composition of materials is able to absorb about 8% recoverable strain. Of course, other materials which can absorb greater and less than 8% can come within the spirit and scope of the invention. This material can be repeatably deflected toward the central body and returned to about its original shape without fatigue. Preferably and additionally, this material can withstand the threshold stress with only a small amount of initial deforming strain and above the threshold stress exhibit substantial and about instantaneous deformation strain which is many times the small amount of initial deforming strain. Such a characteristic is demonstrated in FIG. 118 where it is shown that above a certain threshold stress level, deformation strain is substantially instantaneous up to about 8%. FIG. 118 shows a loading and unloading curve between stress and deformation strain for a typical type of super-elastic material as described above. 
     Preferably, the above super-elastic material is selected to allow deformation of up to about, by way of example only, 8%, at about 20 lbs. to 50 lbs. force applied between a spinous processes. This would cause a sleeve to deflect toward the central body absorbing a substantial amount of the force of the spinous processes in extension. Ideally, the sleeves are designed to absorb 20 lbs. to 100 lbs. before exhibiting the super-elastic effect (threshold stress level) described above. Further, it is possible, depending on the application of the sleeve and the anatomy of the spinal column and the pairs of spinous processes for a particular individual, that the sleeve can be designed for a preferable range of 20 lbs. to 500 lbs. of force before the threshold stress level is reached. Experimental results indicate that with spinous processes of an older individual, that at about 400 pounds force, the spinous process may fracture. Further, such experimental results also indicate that with at least 100 pounds force, the spinous process may experience some compression. Accordingly, ideally the super-elastic material is designed to deform or flex at less than 100 pounds force. 
     In a preferred embodiment, the wall thickness of the sleeve is about 1 mm or {fraction (40/1000)} of an inch (0.040 in.). Preferably the sleeve is designed to experience a combined 1 mm deflection. The combined 1 mm deflection means that there is ½ mm of deflection at the top of the minor dimension and a ½ mm deflection at the bottom of the minor dimension. Both deflections are toward the central body. 
     In a particular embodiment where the sleeve is more circular in cross-section, with an outer dimension of 0.622 in. and a wall thickness of 0.034 in., a 20 lb. load causes a 0.005 in. deflection and a 60 lb. load causes a 0.020 in. deflection (approximately ½ mm). A 100 lb. load would cause a deflection of about 0.04 in. or approximately 1 mm. 
     Thus in summary, the above preferred super-elastic material means that the sleeve can be repeatedly deflected and returned to about its original shape without showing fatigue. The sleeve can withstand a threshold stress with a small amount of deforming strain and at about said threshold stress exhibit about substantially instantaneous deformation strain which is many times the small amount of the forming strain. In other words, such super-elastic qualities mean that the material experiences a plateau stress where the material supports a constant force (stress) over very large strain range as exhibited in FIG.  118 . 
     It is to be understood that for this particular embodiment, bar stock of the super-elastic material is machined into the appropriate form and then heat treated to a final temperature to set the shape of the material by increasing the temperature of the material to 932° Fahrenheit and holding that temperature for five (5) minutes and then quickly quenching the sleeve in water. It is also to be understood that preferably the present nickel titanium super-elastic alloy is selected to have a transition temperature A f  of about 59° Fahrenheit (15° C.). Generally for such devices the transition temperature can be between 15° C. to 65° C. (59° F. to 149° F.), and more preferably 10° C. to 40° C. (50° F. to 104° F.). Preferably, the material is maintained in the body above the transition temperature in order to exhibit optimal elasticity qualities. 
     Alternatively, and preferably, the sleeve can be fabricated by wire Electrical Discharge Machining (EDM) rather than machined. Additionally, the sleeve can be finished using a shot blast technique in order to increase the surface strength and elasticity of the sleeve. 
     Top and side views of the second wing  1032  are shown in FIGS. 94 and 95. Second wing  1032  as in several past embodiments includes a tab  1034  with a bore  1036  which aligns with the bore  1014  of the guide  1010 . In this particular embodiment, the second wing  1032  includes a cut-out  1038  which is sized to fit over the guide  1010 , with the tab  1034  resting in the recess  1012  of the guide  1010 . 
     An alternative configuration of the second wing  1032  is depicted in FIG. 94 a . In this configuration, the second wing  1032  is held at acute angle with respect to the tab  1034 . This is different from the situation in the embodiment of FIGS. 94 and 95 where the second wing is substantially perpendicular to the tab. For the embodiment of the second wing in FIG. 94 a , such embodiment will be utilized as appropriate depending on the shape of the spinous processes. 
     With respect to the alternative second wing  1032  depicted in FIGS. 94 b  and  95   a , elongated tab  1034  has a plurality of closely positioned bores  1036 . The bores, so positioned, appear to form a scallop shape. Each individual scallop portion of the bore  1036  can selectively hold the bolt in order to effectively position the second wing  1032  in three different positions relative to the first wing  1004 . The cut-out  1038  (FIG. 95 a  of this alternative embodiment) is enlarged over that of FIG. 95 as in a position closest to the first wing  1004 , the second wing  1032  is immediately adjacent and must conform to the shape of the sleeve  1016 . 
     Embodiment of FIG.  97   
     Implant  1050  of FIG. 97 is similar to the implant  1000  in FIG. 92 with the major difference being that a second wing is not required. The implant  1050  includes a central body as does implant  1000 . The central body is surrounded by a sleeve  1016  which extends between a first wing  1004  and a guide  1010 . The guide  1010  in this embodiment is substantially cone-shaped without any flats and with no bore as there is no need to receive a second wing. The sleeve and the central body as well as the first wing and guide act in a manner similar to those parts of the implant  1000  in FIG.  92 . It is to be understood a cross-section of this implant  1050  through sleeve  1016  can preferably be like FIG. 93 a . This particular embodiment would be utilized in a situation where it was deemed impractical or unnecessary to use a second wing. This embodiment has the significant advantages of the sleeve being comprised of super-elastic alloy materials as well as the guide being utilized to guide the implant between spinous processes while minimizing damage to the ligament and tissue structures found around the spinous processes. 
     Embodiment of FIG.  98   
     Implant  1060  is depicted in FIG.  98 . This implant is similar to the implants  1000  of FIG.  92  and the implant  1050  of FIG. 97, except that this implant does not have either first or second wings. Implant  1060  includes a sleeve  1016  which surrounds a central body just as central body  1002  of implant  1000  in FIG.  93 . It is to be understood that a cross-section of this implant  1060  through sleeve  1016  can preferably be like FIG. 93 a . Implant  1060  includes a guide  1010  which in this preferred embodiment is cone-shaped. Guide  1010  is located at one end of the central body. At the other end is a stop  1062 . Stop  1062  is used to contain the other end of the sleeve  1016  relative to the central body. This embodiment is held together with a bolt such as bolt  1006  of FIG. 93 that is used for the immediate above two implants. For the implant  1060  of FIG. 98, such a device would be appropriate where the anatomy between the spinous processes was such that it would be undesirable to use either a first or second wing. However, this embodiment affords all the advantageous described hereinabove (FIGS. 92 and 97) with respect to the guide and also with respect to the dynamics of the sleeve. 
     Embodiment of FIGS.  99  and  100   
     FIGS. 99 and 100 depict an implant system  1070 . Implant system  1070  includes a sleeve  1072  which is similar to and has the advantages of sleeve  1016  of the embodiment in FIG.  92 . Sleeve  1072  does not, however, have any spokes. Additionally, implant system  1070  includes an insertion tool  1074 . Insertion tool  1074  includes a guide  1076  which in a preferred embodiment is substantially cone-shaped. Guide  1076  guides the insertion of the sleeve  1072  and the insertion tool  1074  between adjacent spinous processes. The insertion tool  1074  further includes a central body  1078 , a stop  1080 , and a handle  1082 . The guide  1076  at its base has dimensions which are slightly less than the internal dimensions of the sleeve  1074  so that the sleeve can fit over the guide  1076  and rest against the stop  1080 . The tool  1074  with the guide  1076  is used to separate tissues and ligaments and to urge the sleeve  1072  in the space between the spinous processes. Once positioned, the guide insertion tool  1074  can be removed leaving the sleeve  1072  in place. If desired, after the sleeve is positioned, position maintaining mechanisms such as springy wires  1084  made out of appropriate material such as the super-elastic alloys and other materials including titanium, can be inserted using a cannula through the center of the sleeve  1072 . Once inserted, the ends of the retaining wires  1084  (FIG. 99) extend out of both ends of the sleeve  1072 , and due to this springy nature, bend at an angle with respect to the longitudinal axis of the sleeve  1072 . These wires help maintain the position of the sleeve relative to the spinous processes. 
     Embodiment of FIGS.  101 ,  102 ,  102   a ,  103 ,  104 ,  105 ,  106 , and  107   
     Another embodiment of the invention can be seen in FIG. 101 which includes implant  1100 . Implant  1100  has many similar features that are exhibited with respect to implant  1000  in FIG.  92 . Accordingly, elements with similar features and functions would be similarly numbered. Additionally, features that are different from implant  1100  can be, if desired, imported into and become a part of the implant  1000  of FIG.  92 . 
     As with implant  1000 , implant  1100  includes a central body  1002  (FIG. 102) with a first wing  1004  and a bolt  1006  which holds the first wing and the central body together. In this particular embodiment, the central body is made in two portions. The first portion  1102  is in the shape of a truncated cone with an oval or elliptical base and a second portion  1104  includes a cylindrical central portion with a distal end in the shape of a truncated cone  1103  with an oval or elliptical base. In addition, in this particular embodiment, formed with the central body is the guide  1010  which has an oval or elliptical base. Bolt  1006  is used to secure the first wing through the second portion  1104  with the first portion  1102  held in-between. In this particular embodiment, the guide  1010  in addition to including recess  1012  and bore  1014  includes a groove  1106  which receives a portion of the second wing  1032 . 
     In this particular embodiment, the sleeve  1016  is preferably oval or elliptical in shape as can be seen in FIG. 102 a . The central body can be oval, elliptical or circular in cross-section, although other shapes are within the spirit and scope of the invention. The sleeve  1016  held in position due to the fact that the truncated conical portion  1102  and the corresponding truncated conical portion  1103  each have a base that is elliptical or oval in shape. Thus, the sleeve is held in position so that preferably the major dimension of the elliptical sleeve is substantially perpendicular to the major dimension of the first wing. It is to be understood that if the first wing is meant to be put beside the vertebrae so that the first wing is set at an angle other than perpendicular with respect to the vertebrae and that the sleeve may be held in a position so that the major dimension of the sleeve is at an angle other than perpendicular to the major dimension of the first wing and be within the spirit and scope of the invention. This could be accomplished by tightening bolt  1006  with the first wing  1004  and sleeve  1016  so positioned. In such a configuration, the major dimension of the sleeve would be preferably positioned so that it is essentially parallel to the length of the adjacent spinous processes. So configured, the elliptical or oval shape sleeve would bear and distribute the load more evenly over more of its surface. 
     It is to be understood that the sleeve in this embodiment has all the characteristics and advantages described hereinabove with respect to the above-referenced super-elastic sleeves. 
     The second wing as discussed above, can come in a variety of shapes in order to provide for variations in the anatomical form of the spinous processes. Such shapes are depicted in FIGS. 103,  104 ,  105 ,  106 , and  107 . In each configuration, the second wing  1032  has a an upper portion  1108  and a lower portion  1110 . In FIG. 104, the lower portion is thicker than the upper portion in order to accommodate the spinous process, where the lower spinous process is thinner than the upper spinous process. In FIG. 105, both the upper and lower portions are enlarged over the upper and lower portions of FIG. 103 to accommodate both the upper and lower spinous processes being smaller. That is to say that the space between the upper and lower portions of the first and second wings are reduced due to the enlarged upper and lower portions of the second wing. 
     Alternative embodiments of second wings, as shown in FIGS. 104 and 105, are depicted in FIGS. 106 and 107. In these FIGS. 106 and 107, the second wing  1032  accommodates the same anatomical shape and size of the spinous processes as does the second wing in FIGS. 104 and 105 respectively. However, in the embodiments of the second wing  1032  of FIGS. 106 and 107, substantial masses have been removed from the wings. The upper and lower portions  1108  and  1110  are essentially formed or bent in order to extend from the central portion  1112  of the second wing  1032 . 
     It is to be understood that in this embodiment, if desired, the second wing may not have to be used, depending on the anatomy of the spinal column of the body, and this embodiment still has the significant advantages attributable to the guide  1010  and the functionality of the sleeve  1016 . 
     Embodiment of FIGS.  108 ,  109 , and  110   
     The implant  1120  as shown in FIGS. 108 and 109, is similar to implant  1100  which is in turn similar to implant  1000 . Such similar details have already been described above and reference here is made to the unique orientation of the first and second wings  1122  and  1124 . These wings have longitudinal axis  1126  and  1128  respectfully. As can be seen in these figures, the first and second wings  1122 ,  1124  have been rotated so that they both slope inwardly and if they were to continue out of the page of the drawing of FIG. 108, they would meet to form an A-frame structure as is evident from the end view of FIG.  109 . In this particular embodiment, as can be seen in FIGS. 109 and 110, the tab  1034  is provided an acute angle to the remainder of the second wing  1124 . Further, the groove  1018  formed in the implant is sloped in order to accept the second wing  1124 . Accordingly, this present implant  1120  is particularly suited for an application where the spinous process is wider adjacent to the vertebral body and then narrows in size at least some distance distally from the vertebral body. It is to be understood that a cross-section of this implant  1120  through sleeve  1016  can preferably be like FIG. 93 a.    
     Embodiment of FIGS.  111 ,  112 ,  113 ,  114 ,  115 ,  116 , and  117   
     An additional embodiment of the implant  1150  is shown in FIG.  111 . Implant  1150  has features similar to those described with respect to FIG. 94 b.    
     Implant  1150  includes a central body  1152  with a first wing  1154 , where central body  1152  includes elongated groove  1156  which extends to the guide  1158 . A screw  1160  is received in a threaded bore located in the elongated groove  1156 . 
     The second wing  1162  includes a central body  1164  which is substantially perpendicular to the second wing  1162 . 
     The central body  1164  includes a plurality of bores  1166  provided therein. These bores are formed adjacent to each other in order to define a plurality of scallops, each scallop capable of retaining bolt  1160  therein. As can be seen in FIG. 114, the second wing includes a cut-out  1168  such that with the central body  1164  of the second wing received in the groove  1156  of the central body associated with the first wing, the remainder of the second wing is received over the central body  1152  of the implant  1150 . With this implant  1150 , the distance between the first and second wings can be adjusted by selectively placing the bolt  1160  through one of the five specified bores defined by the scalloped plurality of bores  1166 . Accordingly, FIG. 112 depicts the implant where the first and second wings are widest apart in order to accommodate spinous processes of greater thickness. FIG. 111 shows the middle position between the first and second wings in order to accommodate average size spinous processes. 
     It is to be understood that preferably during the surgical process, the central body  1152  is urged between spinous processes. After this has occurred, the second wing is guided by the other sides of the spinous processes from a path which causes the plane of the second wing to move substantially parallel to the plane of the first wing until the central body  1164  associated with the second wing  1162  is received in the groove of  1156  of the central body  1152  associated with the first wing  1154 . After this has occurred, the bolt  1160  is positioned through aligned bores associated with the second wing  1162  and the central body  1152  in order to secure the second wing to the central body. 
     While embodiment  1150  does not depict a sleeve such as sleeve  1016 , such a sleeve  1016  could be placed over body  1152  and be within the spirit of the invention. 
     Embodiments of FIGS.  119   a ,  119   b ,  120   a ,  120   b ,  121   a ,  121   b ,  122   a   122   b ,  122   c ,  123   a ,  123   b ,  124   a ,  124   b , and  124   c    
     Implant  1200  of the invention is depicted in FIGS. 119 a  and  119   b . This implant includes the first wing  1202  and sleeve  1204  and a guide  1206 . An alternative to this embodiment further includes, as required, second wing  1208  as depicted in FIGS. 120 a  and  120   b.    
     As can be seen in FIGS. 121 a  and  121   b , the first wing  1202  includes a bore which receives a central body  1210 . Preferably, the central body is pressed fit through the bore of the first wing although it is to be understood that other securing mechanisms such as through the use of threads and still other mechanisms can be used to accomplish this task. Additionally, in this particular embodiment first and second pins  1212  extend from the first wing  1202 , each along an axis which is substantially parallel to the longitudinal axis  1214  of the central body  1210 . In this particular embodiment, the distal end  1216  of the central body  1210  is threaded in order to be coupled to the guide  1206 . 
     As can be seen in FIGS. 122 a ,  122   b  and  122   c , the guide  1206  in this particular embodiment is pointed in order to allow the implant to be inserted between, and if necessary distract, adjacent spinous processes. The guide  206  includes a threaded bore  1218  which is designed to accept the threaded end  1216  of the central body  1210  in order to secure the guide to the central body and additionally for purposes of retaining the sleeve between the guide  1206  and the first wing  1202 . 
     As can be seen in FIG. 123 a  the sleeve  1204  is preferably cylindrical, and oval or elliptical in shape in cross-section. It is to be understood that sleeve  1204  can have other shapes as described throughout the specification and be within the spirit and scope of the invention. In this particular embodiment, sleeve  1204  has at least one major diameter and one minor diameter in cross-section. Sleeve  1204  includes a central bore  1220  which extends the length of sleeve  1204  and curve grooves  1222  which are formed about central bore  1220  and extend only part way into the body of the sleeve. In this particular embodiment, the curved grooves  1222  describe an arc of about 60°. It is to be understood that in other embodiment, this arc can be less than 60° and extend past 120°. 
     The sleeve  1204  is received over the central body  1210  of the implant  1200  and can rotate thereon about the longitudinal axis  1214  of the central body  1210 . When this particular embodiment is assembled, the grooves  1222  have received therein the pins  1212  that extend from the first wing  1202 . Accordingly, the pins inserted in the grooves  1222  assist in the positioning of the sleeve relative to the remainder of the implant  1200 . With the pins  1212  received in the curved grooves  1222 , the pins limit the extent of the rotation of the sleeve about the central body and relative to the first wing. 
     As can be seen in FIGS. 124 a ,  124   b , and  124   c , the sleeve is free to rotate relative to the longitudinal axis of the central body  1210  and thus relative to the first wing  1202  of the embodiment shown in FIGS. 119 a  and  119   b . The sleeve can rotate relative to a second wing  1208 , when the second wing is utilized in conjunction with the embodiment of FIGS. 119 a  and  119   b . The pins limit the rotation of the sleeve. In an alternative embodiment, the pins are eliminated so that the sleeve can rotate to any position relative to the first wing. 
     It is to be understood that the sleeve can be comprised of biologically acceptable material such as titanium. Additionally, it can be comprised of super-elastic material such as an alloy of nickel and titanium, much as described hereinabove with respect to other embodiments. 
     The great advantage of the use of the sleeve  1204  as depicted in the embodiment of FIGS. 119 a  and  119   b  is that the sleeve can be rotated and repositioned with respect to the first wing  1202 , and/or the second wing  1208  should the second wing be used in the embodiment, in order to more optimally position the implant  1200  between spinous processes. It is to be understood that the cortical bone or the outer shell of the spinous processes is stronger at an anterior position adjacent to the vertebral bodies of the vertebra that at a posterior position distally located from the vertebral bodies. Accordingly, there is some advantage of having the implant  1200  placed as close to the vertebral bodies as is possible. In order to facilitate this and to accommodate the anatomical form of the bone structures, as the implant is inserted between the vertebral bodies and urged toward the vertebral bodies, the sleeve  1204  can be rotated relative to the wings, such as wing  1202 , so that the sleeve is optimally positioned between the spinous processes, and the wing  1202  is optimally positioned relative to the spinous processes. Without this capability, depending on the anatomical form of the bones, it is possible for the wings to become somewhat less than optimally positioned relative to the spinous processes. 
     Embodiments of FIGS.  125 ,  126 , and  127   
     FIGS. 125,  126  and  127  depict three alternative embodiments of the invention as can be seen through a line parallel to line  124 - 124  of FIG. 119 b.    
     In FIG. 125, the sleeve  1204  is rotatable about central body  1210 . In this embodiment, however, the sleeve  1204  design does not include the grooves  1222  as previously depicted in the embodiment shown in FIG. 123 a . Thus, without pins, the sleeve is completely free to rotate about the central body  1210 . 
     An alternative embodiment is shown in FIG.  126 . In this embodiment, the sleeve  1204  is essentially a thin wall cylinder which is spaced from the central body  1210 . Sleeve  1204  is free to move relative to central body  1210 . Sleeve  1204  can rotate relative to central body  1210 . In addition, sleeve  1204  can take a somewhat cocked or skewed position relative to central body  1210 . 
     A further embodiment, it is shown in FIG.  127 . This embodiment is somewhat similar to the embodiment shown in FIG. 126 except that in this case, several pins project from the first wing in order to somewhat limit and restrict the motion of the sleeve  1204 . As shown in FIG. 127, four pins are depicted. It is to be understood however that such an embodiment can include one, two, three, four or more pins and be within the spirit and scope of the invention. It is to be understood that if the embodiment is used with a second wing, that similar pins can extend from the second wing. However, in the embodiment using a second wing, the pins would preferably be somewhat flexible so that they could snap into the inside of the sleeve  1204  as the second wing is inserted relative to the central body and secured in place. In the embodiment shown in FIG. 127, the sleeve  1204  is free to rotate about the longitudinal axis of the central body  1210  and is somewhat restricted in this motion and its ability to become skewed relative to the longitudinal axis of the central body by the pins. 
     Embodiments of FIGS.  128  and  129   
     The embodiments of FIG. 128 is an advantageous alternative to that of FIG. 93 a . In this embodiment, the central body  1002  is similar to that as shown in FIG. 93 a . The sleeve  116  is comprised of two sleeve portions  1016   a  and  1016   b . The sleeve portions are preferably formed from flat stock material which is substantially easier to form than having the sleeve formed or machined from solid bar stock material. A further advantage of the sleeve  1016 , if formed of super-elastic material, is that the sleeve can be formed in a manner which optimizes the super-elastic characteristics of such material in order to enhance its ability to repeatedly deflect under load. In this particular embodiment, the sleeve portions  1016   a  and  1016   b  are somewhat C-shaped and then after being formed, are snapped into the grooves of the central body  1002 . 
     An alternative embodiment of the invention is shown in FIG.  128 . This embodiment is most favorably used with the embodiment of FIGS. 119 a  and  119   b . In this particular embodiment, the sleeve  1204  is designed to rotate about the central body  1210 . Sleeve  1204  includes a central member  1230  which includes a bore that receives the central body  1210 . The central member  1230  is rotatable about the central body  1210  of the implant  1200 . The central member  1230  includes first and second grooves  1232  and  1234 . These grooves can receive C-shaped sleeve members  1204   a  and  1204   b . These C-shaped sleeve members are similar in construction and design to the C-shaped sleeve members shown above with respect to FIG.  128 . These sleeve members can be snapped into position relative to the central member  1230  of the sleeve  1204 . It is to be understood that other mechanisms can be used to secure the C-shaped sleeve member relative to the central member of the sleeve and be within the spirit and scope of the invention. Further, it is to be understood that the sleeve members  1204   a  and  1204   b  can be formed from a single flat stock material such that one of the grooves  1232  and  1234  receives continuous piece of flat material which has been appropriately bent and the other grooves receives two ends of the sleeve. 
     INDUSTRIAL APPLICABILITY 
     From the above, it is evident that the present invention can be used to relieve pain caused by spinal stenosis in the form of, by way of example only, central canal stenosis or foraminal (lateral) stenosis. These implants have the ability to flatten the natural curvature of the spine and open the neural foramen and the spacing between adjacent vertebra to relieve problems associated with the above-mentioned lateral and central stenosis. Additionally, the invention can be used to relieve pain associated with facet arthropathy. The present invention is minimally invasive and can be used on an outpatient basis. 
     Additional aspects, objects and advantages of the invention can be obtained through a review of the appendant claims and figures. 
     It is to be understood that other embodiments can be fabricated and come within the spirit and scope of the claims.