Abstract:
Interspinous process implants are disclosed. Also disclosed are systems and kits including such implants, methods of inserting such implants, and methods of alleviating pain or discomfort associated with the spinal column.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a continuation application claiming priority to U.S. patent application Ser. No. 11/366,388 filed on Mar. 3, 2006, which claims priority to U.S. Provisional Patent Application Ser. No. 60/689,532 filed on Jun. 13, 2005, the entire contents of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention is generally directed to interspinous process implants, systems and kits including such implants, methods of inserting such implants, and methods of treating spinal stenosis or for alleviating pain or discomfort associated with the spinal column. 
       BACKGROUND OF THE INVENTION 
       [0003]    Occurrences of spinal stenosis are increasing as society ages. Spinal stenosis is the narrowing of the spinal canal, lateral recess or neural foramen, characterized by a reduction in the available space for the passage of blood vessels and nerves. Clinical symptoms of spinal stenosis include extremity pain, radiculopathy, sensory or motor deficit, bladder or bowel dysfunction, and neurogenic claudication. Pain associated with such stenosis can be relieved by surgical or non-surgical treatments, such as medication, physical therapy, back braces and the like. 
         [0004]    There is a need for implants that may be placed between spinal processes for minimally invasive surgical treatment of spinal stenosis. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention is directed to minimally invasive implants, in particular, interspinous process implants or spacers. The invention is further directed to systems and kits including such implants, methods of inserting such implants, and methods of alleviating pain or discomfort associated with the spinal column. 
         [0006]    The present invention provides spacers or implants and methods for relieving pain and other symptoms associated with spinal stenosis, by relieving pressure and restrictions on the blood vessels and nerves. Such alleviation of pressure may be accomplished in the present invention through the use of an implant placed between the spinous process of adjacent vertebra. While the implants and methods of the invention particularly address the needs of the elderly, the invention can be used with individuals of all ages and sizes where a spacer between spinous processes would be beneficial. 
         [0007]    In certain aspects of the invention, various implants are provided for creating, increasing, or substantially maintaining a desired distraction or spacing between a first spinous process and a second spinous process (adjacent spinous processes). In another aspect of the invention, implants may be extended to create, increase or substantially maintain a desired distraction or spacing of more than two adjacent spinous processes. 
         [0008]    In another aspect of the invention, implants in accordance with the present invention may be attached to one or more spinous processes or other portion of the spine, or may attach to itself in such a manner as to secure the implant between two adjacent spinous processes. In yet other aspects of the invention, implants in accordance with the present invention may be secured in place with respect to spinous processes by mechanical forces resulting from the design of the implant or attachments to the implant, and/or surface modifications thereto. 
         [0009]    In another aspect of the present invention, methods are provided for treating spinal stenosis. In yet further aspects of the invention, methods are provided for inserting implants. These methods may include implanting a device to create, increase, or maintain a desired amount of distraction between adjacent first and second spinous processes. Methods may include creating an incision in a patient, removing any interspinous ligaments in a position in which the implant is to be placed in the patient, sizing the space between adjacent spinous processes, and inserting an implant of the appropriate size between the spinous processes. In another aspect of the invention, methods may further include securing the implant. In another aspect of the invention, methods of the present invention may include distracting the spinous processes apart from one another before sizing and/or before inserting the implant. 
         [0010]    In a further aspect of the invention kits are provided that include one or more implants, and optionally any tools or devices that may be required or useful in inserting the implant into a patient, such as tools or devices that may be useful in distracting spinous processes, and/or selecting, inserting, positioning, and/or securing one or more implants. 
         [0011]    In a further aspect of the invention systems are provided that include at least one implant and at least one fastening device. Systems in accordance with the present invention may further include one or more of the following: a tool or device for removing any interspinous ligaments in the way of inserting the implant; a tool or device for sizing the space between adjacent spinous processes; and a tool or device for distracting spinous processes, and/or selecting, inserting, positioning, and/or securing one or more implants. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The invention will be more readily understood with reference to the embodiments thereof illustrated in the attached figures, in which: 
           [0013]      FIGS. 1   a - 1   b  depict one embodiment of an implant according to the present invention for creating, increasing, or maintaining distraction between adjacent spinous processes; 
           [0014]      FIG. 1   c  is a perspective view of the implant of  FIGS. 1   a  and  1   b;    
           [0015]      FIG. 1   d  is a side view of the implant of  FIGS. 1   a - 1   c  shown in a first implantation position in relation to the spinous processes between which the implant is implanted; 
           [0016]      FIG. 1   e  is a side view of the implant of  FIGS. 1   a - 1   c  shown in a second implantation position in relation to the spinous processes between which the implant is implanted; 
           [0017]      FIG. 1   f  depicts a stapler that may be used to secure an implant to one or more spinous processes; 
           [0018]      FIG. 1   g  depicts a device that may be used to determine a space between spinous processes and/or a desired size or shape of implant to be used; 
           [0019]      FIGS. 2 and 3   a - 3   c  depict implants according to other embodiments of the present invention; 
           [0020]      FIGS. 4   a - 4   b  depict a perspective and side view of implants according other embodiments of the present invention; 
           [0021]      FIGS. 5 ,  6   a , and  7  depict a side view of implants according to other embodiments of the present invention in relation to the spinal processes between which the implants are implanted, where the implants are secured to the spinous processes by a fastening device; 
           [0022]      FIG. 6   b  depicts a front view of the implant according to  FIG. 6   a;    
           [0023]      FIG. 8  depicts a side view of the implant of  FIG. 7 , before being implanted between spinous processes; 
           [0024]      FIG. 9  depicts other embodiments of implants of the invention; 
           [0025]      FIG. 10  depicts other embodiments of implants of the invention; 
           [0026]      FIG. 11  depicts other embodiments of implants of the invention in relation to the spinal processes between which the implants are implanted; 
           [0027]      FIG. 12  depicts other embodiments of implants of the invention in relation to the spinal processes between which the implants are implanted; 
           [0028]      FIGS. 13   a - 13   b  depict a side and front view of other embodiments of implants of the invention, where the side view is depicted in relation to the spinous processes between which the implants are implanted; 
           [0029]      FIGS. 14   a - 14   b  depict a side and front view of other embodiments of implants of the invention, where the side view is depicted in relation to the spinal processes between which the implants are implanted; 
           [0030]      FIGS. 15   a - 15   b  depict a side and front view of other embodiments of the invention, where the side view is depicted in relation to the spinal processes between which the implants are implanted; 
           [0031]      FIGS. 16-18  depict other embodiments of implants of the invention; 
           [0032]      FIGS. 19-21  depict other embodiments of implants of the invention; 
           [0033]      FIGS. 22-24  depict embodiments of the present invention in which the implants are attached to portions of the spine other than a spinous process; 
           [0034]      FIGS. 25-26  depict other embodiments of implants of the invention; 
           [0035]      FIG. 27   a  depicts other embodiments of implants of the invention; 
           [0036]      FIG. 27   b  depicts a side view of the center portion of  FIG. 27   a;    
           [0037]      FIG. 28  is a perspective view of another embodiment of an implant according to the present invention for creating, increasing, or maintaining distraction between adjacent spinous processes; 
           [0038]      FIG. 29  is a front view of the implant of  FIG. 28 ; 
           [0039]      FIG. 30  is a cross-sectional view of the implant of  FIG. 29  taken along line  30 - 30 ; 
           [0040]      FIG. 31  is a bottom view of the implant of  FIGS. 28-30 ; 
           [0041]      FIG. 32  is an end view of the implant of  FIGS. 28-31 ; 
           [0042]      FIG. 33  is another end view of the implant of  FIGS. 28-32 ; 
           [0043]      FIG. 34  is a perspective view of another embodiment of an implant according to the present invention; 
           [0044]      FIG. 35  is a front view of the implant of  FIG. 34 ; 
           [0045]      FIG. 36  is a perspective view of another embodiment of an implant according to the present invention; 
           [0046]      FIG. 37  is a perspective view of another embodiment of an implant according to the present invention; 
           [0047]      FIG. 38  is an end view of the implant of  FIG. 37 ; 
           [0048]      FIGS. 39-42  are perspective views demonstrating steps according to one embodiment of a method of installation of the implant of  FIGS. 28-32 ; 
           [0049]      FIGS. 43-44  depict one embodiment of a muscle distraction tool constructed in accordance with the present invention; 
           [0050]      FIGS. 45-46  depict one embodiment of a dilation tool constructed in accordance with the present invention; 
           [0051]      FIGS. 47-48  depict one embodiment of a facet reamer tool constructed in accordance with the present invention; 
           [0052]      FIG. 49  is a perspective view of one embodiment of a facet reamer sleeve for use with the reamer tool of  FIGS. 47-48 ; and 
           [0053]      FIGS. 50-52  depict one embodiment of a trial assembly constructed in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0054]    Embodiments of the invention will now be described. The following detailed description of the invention is not intended to be illustrative of all embodiments. In describing embodiments of the present invention, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. It is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. 
       Implants 
       [0055]    The present invention is directed to minimally invasive implants, in particular, interspinous process spacers. Implants in accordance with the present invention may come in many shapes and sizes. The illustrative embodiments provided herein-below provide guidance as to the many types of implants that may be advantageously used in accordance with the present invention. In particular, the implants of the present invention are adapted such that their insertion technique (including methods of the present invention) is minimally invasive, simpler, and/or safer than previously discussed techniques. Implants according to the present invention may be advantageously inserted into a patient as an out-patient procedure. 
         [0056]    Embodiments of the present invention include implants adapted to be placed between first and second adjacent spinous processes. The implants may be adapted such that after insertion of an implant into a patient, a portion of the implant maintains a desired amount of distraction or spacing between two adjacent spinous processes. The implants or portions thereof that substantially maintain a desired spacing between spinous processes are also referred to herein as “spacers.” In various embodiments described herein, the implants may include spinous process support surfaces, indented portions or saddle portions spaced apart by a distance (a), which corresponds to a desired distance for distraction or spacing of two adjacent spinous processes. Other embodiments similarly provide a desired distance for distraction or spacing of two adjacent spinous processes. Depending on the material and/or design of the implant, the desired distraction or spacing distance may vary somewhat after insertion, for example if a patient moves its spine into a position that causes further distraction. For example, in certain embodiments the implant may be resiliently compressible or expandable in the cranial-caudal direction such that the implant may support and or adjust to dynamic movement of the spine. Although not depicted in the figures discussed below, it is contemplated that embodiments of the present invention may be extended to provide distraction or spacing of more than two adjacent spinous processes. 
         [0057]    Implants in accordance with the present invention may be attached to one or more spinous processes or other portion of the spine, or may attach to itself in such a manner as to secure the implant between two adjacent spinal processes. By way of example, implants in accordance with the present invention may be attached to one or both spinous processes or other portion of the spine (see e.g.,  FIGS. 22-24 ) by one or more pins, screws, wires, cables, straps, surgical rope, sutures, elastic bands, or other fastening devices. Alternatively implants of the present invention may secure themselves in place without a fastening device attached directly to a spinous process or other portion of the spine (see e.g.,  FIGS. 19-21 ). “Securing” implants between spinous processes, does not require that the implant not move at all, but rather means that the implant does not move so far away from between the spinous processes that it does not perform the function of maintaining a desired distraction distance or space between the adjacent spinous processes. 
         [0058]    Implants in accordance with the present invention may be secured between spinous processes by methods other than using a fastening device. For example, according to certain embodiments, implants in accordance with the present invention may be secured in place with respect to spinous processes by mechanical forces resulting from the design of the implant, including the shape itself. Exemplary implants may also be secured to spinous processes, by surface modifications to portions of the implant, such as to create frictional forces or other bonds between the implant and spinous processes. Such surface modifications may include mechanical modifications to the surface (see e.g., spikes in  FIG. 16 ) and/or one or more coatings. Such mechanical forces and/or surface modifications may be utilized in addition to, or in place of various other attachment methods described herein. 
         [0059]    Implants in accordance with the present invention may be made of one or more materials suitable for implantation into the spine of a mammalian patient. Materials in accordance with the present invention may be biocompatible with a mammalian patient and/or may have one or more surface coatings or treatments that allow the spacers to be biocompatible. Materials in accordance with the present invention may include one or more materials having sufficient load capability and/or strength to maintain the desired spacing or distraction between spinous processes. Depending on the design employed, certain embodiments may have components or portions made of a material having certain flexibility, as desired for the particular application. Additionally, the materials of the present invention may be made of one or more materials that maintain their composition and shape for as long a time as possible without degrading or decomposing or changing shape, such that replacement of the implant is avoided. 
         [0060]    Suitable materials for use in accordance with the present invention would be known to those skilled in the art. Non-limiting examples include one or more materials selected from titanium, polyetheretherketone (PEEK), ceramics, deformable materials, bone, allograft, demineralized or partially demineralized bone, allograft ligament, and polyurethane (for example, for portions of the insert where cushioning is desired). Similarly, any fastening devices may be made of materials having one or more of the properties set forth with respect to the implant itself. For example, screws or pins may include titanium and straps may include polyethylene. In some embodiments, primarily radiolucent material may be used. In this regard, radio-opaque material or markers may be used in combination with the radiolucent material to facilitate implantation. Exemplary radio-opaque material includes but is not limited to titanium alloys, tantalum or other known radio-opaque marker material. As indicated above, implants in accordance with the present invention may have one or more portions that may have modified surfaces, surface coatings, and/or attachments to the surface, which may assist in maintaining the spacer in a desired position, for example by friction. Suitable surface modifications, coatings, and attachment materials would be known to those skilled in the art, taking into consideration the purpose for such modification, coating, and/or attachment. 
         [0061]    Implants according to the present invention may be adapted to be inserted between a first and second spinous process at any region in the spine. Although typically implants according to the present invention may be inserted in the lumbar region, it is contemplated that it is possible to configure inserts according to the present invention for insertion into other regions such as for example, the thoracic or cervical region. In general, implants according to the invention may have varying profiles when viewed in a saggital plane. In this regard, the implants can have varied cross-sectional shapes to conform to the varied anatomical shapes of the interspinous spaces of the spine. 
       Methods for Treating Stenosis and Methods of Inserting an Implant 
       [0062]    Methods are provided for treating spinal stenosis. Methods are also provided for inserting an implant. These methods may include implanting a device to create, increase, or maintain a desired amount of distraction, space, or distance between adjacent first and second spinous processes. The adjacent first and second spinal processes may be accessed by various methods known by practitioners skilled in the art, for example, by accessing the spinous processes from at least one lateral side/unilateral, bilateral, or midline posterior approach. 
         [0063]    Certain methods of the present invention include creating an incision in a patient to be treated, removing/dilating any interspinous ligaments in a position in which the implant is to be placed in the patient, sizing the space between adjacent spinous processes (for example using trials), and inserting an implant of the appropriate size between the adjacent spinous processes. Methods of the present invention may include securing the implant to one or more of the spinous processes, to one or more other portions of the patient&#39;s spine, and/or to itself such that the implant maintains its position between the spinous processes. 
         [0064]    Methods of the present invention may include dilating or distracting the spinous processes apart from one another before sizing and/or before inserting the implant. Methods may vary depending on which implant is being inserted into a patient. For example, certain implants may require distracting the spinous processes apart before inserting the implant, while other implants may themselves dilate or distract the spinous processes while inserting the implant. In embodiments where the implants themselves dilate or distract the spinous process, the implant may have, for example, a predetermined shape to dilate, distract, or otherwise move or separate apart adjacent spinous processes such as a cam or cam-like profile, it may have a distraction device that is deployed, and/or it may have a tapered expander to distract an opening between the adjacent spinous processes or other features to facilitate distraction of the adjacent spinous processes. 
         [0065]    According to certain embodiments, spacers may be placed between the spinous processes anterior to the supraspinous ligament, avoiding the nerves in the spinal canal. The procedure may be performed under local anesthesia. For surgical procedures, in which an implant is being inserted into the lumbar region, the patient may be placed in the right lateral decubitus position with the lumbar spine flexed. 
         [0066]    According to certain embodiments, one or more probes may be used to locate the space between the spinous processes. Depending on the design of the spacer to be inserted, the space may be widened, for example with a dilator before inserting the implant. 
         [0067]    While the present invention is satisfied by embodiments in many different forms, there will herein be described in detail embodiments of the invention, with the understanding that the present disclosure and examples are to be considered as exemplary and/or illustrative of the principles of the invention and are not intended to limit the scope of the invention to the embodiments illustrated and described. As would be apparent to skilled artisans, various changes and modifications are possible and are contemplated within the scope of the invention described, and may be made by persons skilled in the art without departure from the spirit of the invention. 
       Systems and Kits 
       [0068]    Kits in accordance with the present invention may include one or more implants. For example, kits having at least one implant such as those depicted in  FIGS. 1   a - 1   d  or  2 , may include various sizes of implants having varying distances (a), for example incremental distances, such as 2 mm increments. 
         [0069]    Kits in accordance with the present invention may further include one or more tools or other devices that may be useful in distracting spinous processes, and/or selecting, inserting, positioning, and/or securing one or more implants. By way of non-limiting example, such tools and/or devices may include one or more of the following: those adapted to remove/dilate interspinous ligaments in the way of inserting the implant into the patient; those for sizing the space between adjacent spinous processes such as one or more trials of varying or various sizes (see e.g., the device depicted in  FIG. 1   g ); those for inserting an implant between adjacent spinous processes; those for distracting the spinous processes apart from one another; and those for securing one or more implants between adjacent spinous processes. 
         [0070]    Tools or devices for distracting the spinous processes may be adapted for example, to provide for distraction in the range of about 5 mm to about 15 mm. However, devices that can distract up to and above 22 mm may be used depending on the characteristics of the patient. 
         [0071]    Tools and devices that may be used to secure one or more implants between spinous processes may include for example, one or more pins, screws, wires, cables, straps, surgical rope, sutures, or other fastening devices, and/or tools for inserting, securing or tightening such fastening devices. For example, a stapler such as that depicted in  FIG. 1   f  may be used in some embodiments to secure an implant such as that depicted in  FIGS. 1   a - 1   e.    
         [0072]    In a further aspect of the invention, systems may be provided that include at least one implant and at least one fastening device. Systems in accordance with the present invention may further include one or more of the following: one or more tools or devices for removing any interspinous ligaments in the way of inserting the implant; one or more tools or devices for sizing the space between adjacent spinous processes; and one or more tools or devices for distracting spinous processes, and/or selecting, inserting, positioning, and/or securing one or more implants. 
         [0073]    Further non-limiting examples of implants, methods, kits and systems in accordance with the present invention are set forth below with respect to the described implant embodiments. 
         [0074]    Referring now to  FIGS. 1   a - 1   e,  one exemplary embodiment of an implant  1  according to the invention is shown for creating, increasing, or maintaining distraction between adjacent spinous processes. In general, implant  1  is adapted and configured to be placed between adjacent spinous processes. For example, referring to  FIGS. 1   d  and  1   e,  a side view of implant  1  is shown in implanted positions in relation to two adjacent spinous processes  5  between which the implant is implanted. As best seen in  FIGS. 1   a - 1   c,  implant  1  is a unitary body with a general oval, ovoid, oblong, football-like shape and generally includes at least one rounded lateral side surface or portion  2 , and two or more indented portions, troughs, or saddle portions  3  adjacent the longitudinal ends. In one embodiment, implant  1  comprises two rounded lateral side surfaces or portions  2 . Saddle portions  3  are generally configured and dimensioned to engage the spinous processes  5  and each generally includes a saddle surface  4  with tines or walls  6  extending longitudinally beyond the lateral sides thereof. Saddle surfaces  4  are spaced longitudinally apart by a distance (a), which generally corresponds to the desired distance for distraction or spacing of two adjacent spinous processes  5 . Implant  1  has a maximum lateral width (b) measured between the outermost point or section of the lateral side surfaces or portions  2 . The distance (a) may vary with respect to distance (b) and in a preferred embodiment distance (a) is greater than distance (b). According to certain embodiments distance (a) may be proportional to distance (b). Non-limiting examples of distance (a) may include any distance from about 3 mm to about 25 mm or from about 7 mm to about 21 mm. 
         [0075]    Walls  6  are generally spaced in the lateral direction a sufficient distance to accommodate the width of a spinous process therebetween and walls  6  may contact or engage the lateral sides of the spinous process when the implant is implanted. In this regard, walls  6  generally prevent or limit lateral movement of the implant when the implant is implanted, such as for example when in the position shown in  FIG. 1   e.    
         [0076]    In certain variations of the present embodiment, implant  1  may be attached to one or both of the adjacent spinous processes to secure the implant. By way of non-limiting example, the implant may have openings  8 , which permit the attachment of the implant to one or both spinous processes by one or more fastening devices. As discussed above, according to certain embodiments, implants in accordance with the present invention may be secured in place with respect to spinous processes by mechanical forces resulting from the design of the implant, including the shape itself. In other embodiments, implant  1  may also be secured to spinous processes, by surface modifications to portions of the implant, such as modifications to the inner surfaces of walls  6  to create frictional forces or other bonds between the implant and spinous processes. Such surface modifications may include mechanical modifications to the surface and/or one or more coatings. Such mechanical forces and/or surface modifications may be utilized in addition to, or in place of (in which case, the implant may have no openings  8 ) various other attachment methods described herein. 
         [0077]      FIG. 2  exemplifies another implant  10  according to the present invention adapted to be placed between adjacent spinous processes. Implant  10  comprises at least one rounded lateral side surface or portion  12 , and two or more indented portions, troughs, or saddle portions  3 . Implant  10  of  FIG. 2  is similar to implant  1  of  FIG. 1 , except that the lateral side surface(s) or rounded portion(s)  12  may include one or more portions  16  that modify the curve of the rounded portion(s)  12 . In this embodiment, portion  16  reflects a concave section positioned between convex sections of rounded portion(s)  12 . In alternate embodiments, lateral side surfaces or portions  12  may have differing shapes other than simple curves that may facilitate rotation in situ and/or provide additional mechanical advantage to distract the spinous processes in operation. Similar to implant  1 , the saddle portions  3  are spaced apart by a distance (a), which generally corresponds to the desired distance for distraction or spacing of two adjacent spinous processes. 
         [0078]    According to methods of the present invention, implants  1 ,  10  may be inserted between two adjacent spinous processes  5  wherein a portion of at least one rounded portion  2 ,  12  may contact at least one of the adjacent spinous processes as shown, for example in  FIG. 1   d  for implant  1 , and the implant may be rotated until the two adjacent spinous processes are positioned into the saddle portions  3  of the implant, as shown in  FIG. 1   e.    
         [0079]    The implant itself may serve to dilate or distract the spinous processes as it is being inserted and/or after insertion. For example, in embodiments in which the implant is similar to that depicted in  FIGS. 1 and 2 , the implant may be initially inserted laterally between the compressed adjacent spinous processes as shown in  FIG. 1   d.  The supraspinous ligament may or may not be removed. In an initial pre-implantation condition, the adjacent spinous process may be compressed such that the initial space or longitudinal distance between the processes may be equal to or smaller than distance (b) of implant  1 . During lateral insertion of the implant, one or more lateral side surfaces or portions  2 ,  12  of the implant may contact one or both of the spinous processes  5  and may initially distract the processes a distance (b). As the implant is inserted further between the spinous processes and rotated, the rounded portion(s) may distract the spinous processes further apart from one another, until the implant is rotated into a longitudinal or implanted position and the spinous processes are fitted into the saddle portions  3  of the implant. In operation, lateral side surfaces or portions  2 ,  12  of implants  1 ,  10  engage the adjacent spinous processes as the implant is rotated to act or perform in a cam-like manner to translate the rotational force to separate the spinous processes in the longitudinal or cranial-caudal direction as the implant is rotated. In one embodiment, implants  1 ,  10  may be rotated about 90 degrees or from the horizontal or lateral position to the vertical or longitudinal position. The maximum distraction of spinous processes by the implant is distance (c) depicted in  FIG. 1   a.  Once the implant is implanted and after the spinous processes are fitted into the saddle portions  3  of the implant, the implant may maintain the spinous processes in a distracted or spaced condition, for example where the distance (a) of the implant is greater than a pre-implantation distance between the spinous processes. 
         [0080]    Kits having at least one implant such as those depicted in  FIGS. 1 and 2 , may include various sizes of implants having varying distances (a), for example incremental distances, such as 2 mm increments. 
         [0081]    Tools and devices that may be used to secure one or more implants between spinous processes may include for example, one or more pins, screws, wires, cables, straps, surgical rope, sutures, or other fastening devices, and/or tools for inserting, securing or tightening such fastening devices. For example, a staple device  7  such as that depicted in  FIG. 1   f  may be used to secure an implant such as those depicted in  FIGS. 1   a - 1   e.  Staple device  7  may be used to crimp the implant in place, create holes in the spinous process in alignment with openings  8  to facilitate insertion of alternate fastening devices, and/or clasp the implant to the spinous process and remain in-situ. The following is a non-limiting example of how such a staple device may be used. Pins, screws or other fastening devices  9  at the open ends  11  of the staple device may be aligned adjacent to the openings  8  of the implant on either side of a spinous process after the implant is positioned with respect to the spinous processes. The open ends  11  of the staple device are then compressed together such that the fastening devices  9  secure the implant to the spinous process through openings  8  of the implant. 
         [0082]    Referring to  FIGS. 3   a - 3   c,  additional embodiments of implants according to the present invention adapted to be placed between adjacent spinous processes are shown. Implants  30 ,  32 , and  34  generally comprise at least one substantially straight lateral side surface or portion  36 , and two or more indented portions, troughs, or saddle portions  3  adjacent the longitudinal ends. Each of the straight side portions  36  may include proximal ends  37  and distal ends  38  that are rounded such as shown in  FIG. 3   c  with respect to implant  32 , or squared such as shown in  FIG. 3   a  with respect to implant  30 . In embodiments having more than one straight portion  36 , in one variation at least two of the straight portions may be substantially parallel to one another, such as shown in  FIG. 3   a  with respect to implant  30 . In alternative embodiments, the at least two straight portions  36  may not be substantially parallel, such as shown in  FIG. 3   b  with respect to implant  32  where proximal ends  37  of straight portions  36  are spaced laterally closer together than the corresponding distal ends  38  of the straight portions  36 , creating a tapered configuration. 
         [0083]    As with previous embodiments, the saddle portions  3  are spaced longitudinally apart by a distance (a), which may vary as described herein with respect to other embodiments of the invention. As with previous embodiments, walls  6  of saddle portions  3  may be spaced laterally apart a sufficient distance to allow the spinous processes to fit within the saddle portions  3 . Walls  6  may also be close enough together such that when the implants are positioned such that the spinous processes are within saddle portions  3 , the implant may be attached to one or both of the adjacent spinous processes. By way of example, the implant may have openings  8 , which allow one to attach the implant to one or both spinous processes by one or more fastening devices or methods as described herein. 
         [0084]    According to methods of the present invention, the implant may be inserted between two adjacent spinous processes and the implant may be rotated until the two adjacent spinous processes are positioned into the saddle portions  3  of the implant. Certain methods of the present invention include creating an incision in a patient to be treated, removing any spinous ligaments in a position in which the implant is to be placed in the patient, sizing the space between adjacent spinous processes (for example using trial blocks or spacers), and inserting an implant of the appropriate size between the adjacent spinous processes. Methods of the present invention may include distracting the spinous processes apart from one another before sizing and/or before inserting the implant. Methods of the present invention may include securing the implant to one or more of the spinous processes and/or to one or more other portions of the patient&#39;s spine, such that the implant maintains its position between the spinous processes. 
         [0085]    The implant itself may serve to distract the spinous processes as it is being inserted and/or after insertion. For example, implant  32  of  FIG. 3   b  may be inserted with the narrow or tapered end (where the ends  37  of sides  36  are laterally closer together) first. In operation, as the implant is further inserted between the spinous processes, the increasing distance between sides  36  may serve to distract the spinous processes from one another. 
         [0086]    Referring to  FIGS. 4   a - 4   b,  another embodiment of an implant  40  adapted to be placed between adjacent spinous processes is shown. Implant  40  generally comprises an oblong body and includes a narrow end  42  and a wide end  43  to form a wedge-like shape. 
         [0087]    According to methods of the present invention, the implant may be inserted between two adjacent spinous processes such that the narrow end  42  is inserted first and the wedge-like shape serves to distract the spinous processes as the implant is further inserted between the spinous processes. 
         [0088]    Referring to  FIGS. 5-8 , additional embodiments of implants according to the invention for creating, increasing, or maintaining distraction between adjacent spinous processes are shown. In particular,  FIGS. 5-8  exemplify implants adapted to be placed between adjacent spinous processes, which generally include a main body  54  and at least two arms  56 . In general, the implants may be resiliently compressible or expandable such that the implants may support and or adjust to dynamic movement of the spine. In this regard, the implants may include one or more biasing members or springs  58  or other configurations or materials that allow the body to dynamically distract less or more distance. 
         [0089]    Referring to  FIG. 5  one exemplary embodiment of an implant  50  is shown wherein the entire device is positioned between the spinous processes. In this regard, arms  56  of implant  50  are configured to contact, support, or otherwise engage the respective superior and inferior surfaces of the adjacent spinous process without contact with the lateral or side surfaces of the spinous processes: In this embodiment, implant  50  may be attached directly or secured to the superior and inferior surfaces or the spinous processes for example by one or more fastening devices  57 , such as screws, as shown in  FIG. 5 . Biasing member or spring  58  permits arms  56  of implant  50  to resiliently compress together or expand apart in the cranial-caudal direction. In this regard, spring  58  provides dynamic support between the adjacent spinous processes and accommodates extension and flexion of the spine. 
         [0090]    Referring to  FIGS. 6   a  and  6   b , another embodiment of an implant  60  of the present invention is shown. Implant  60  is similar to implant  50  described above, except the arms  56  or portions thereof are not entirely positioned between the spinous processes. In this embodiment, the arms  56  of implant  60  may be attached for example, to the sides of the spinous processes  5  by one or more fastening devices  57 , such as screws, as depicted in  FIG. 6   a.    
         [0091]    As best seen in  FIG. 6   b , implant  60  may include saddle portions  3  which include arms or walls  6 . As depicted in  FIG. 6   b , in one embodiment implant  60  may have at least one saddle portion  3 . Arms or walls  6  may be spaced laterally apart a sufficient distance to allow the spinous processes  5  to fit within the saddle portions  3 . Arms or walls  6  may also be close enough together such that when the implants are positioned such that the spinous processes are within saddle portions  3 , the implant may be attached to one or both of the adjacent spinous processes as discussed above and/or secured in place by virtue of its design. 
         [0092]      FIGS. 7 and 8  depict embodiments similar to those shown in  FIG. 5  where the entire device is positioned between the spinous processes. The embodiments of  FIGS. 7 and 8  may be attached to the spinous processes for example by one or more fastening devices  72 , as shown in  FIGS. 7 and 8 . Fastening device  72  may be attached to an arm  56  of the implant and a spinous process  5 . Optionally, a strap  74  or other fastening device may be used to further secure the implant to one or both spinous processes. 
         [0093]    Referring to  FIG. 9 , another exemplary embodiment of an implant  90  according to the present invention is shown. Implant  90  generally comprises a distal or first end  91  having a first shaft  92  extending proximally therefrom and a proximal or second end  93  with a second shaft  94  extending distally therefrom. A spring  96  is positioned concentric to shaft  92  and configured and dimensioned to fit coaxially inside a substantially cylindrical opening of the second shaft  94  of second end  93 . The configuration may allow implant  90  to be somewhat flexible after implantation between spinal processes, by virtue of the spring  96 , which allows first end  91  and second end  93  to move further apart and closer together with respect to each other after implantation into the patient. Similar to previously described embodiments, spring  96  provides dynamic support between the adjacent spinous processes and accommodates extension and flexion of the spine. 
         [0094]    According to other embodiments, the spring configuration facilitates implantation into the patient as it allows the first end  91  and second end  93  to be compressed together during implantation and released, similar to, for example, a pen-spring. In this regard, a surgeon or other operator of the device may position the spinous processes in saddle portions  3  of the first and second ends  91 ,  93 , more easily. 
         [0095]    In certain embodiment, implant  90  may be secured in position between the spinous processes for example, by one or more screws or pins  97  and/or by one or more straps  98  positioned around one or both spinous processes. 
         [0096]    Referring to  FIG. 10  another implant  100  according to the invention is shown. Implant  100  generally comprises a first portion  101  and a second portion  103 . One or both portions may have a threaded connection or turnbuckle  104  that threadedly connects the first and second portions together. Implant  100  may be expanded or contracted in the cranial-caudal or longitudinal direction by rotating tumbuckle(s)  104 . In this regard, implant  100  may be adjusted after implantation between spinal processes, by virtue of the threaded connection between the first and second portions  101 ,  103 , which allow the first and second portions to move further apart and closer together with respect to each other after implant  100  is inserted into the patient. In this regard, implant  100  may be used to distract the adjacent spinous processes in situ without the need for an additional distraction tool. Similar to previous embodiments, implant  100  may be secured in position between the spinous processes for example, by one or more screws or pins and/or by one or more straps  106  that wrap around one or both spinous processes. Both of the first and second portions of implant  100  may be inserted between the spinous processes substantially simultaneously, or one portion may be inserted followed by the other portion. 
         [0097]    Referring to  FIG. 11 , another embodiment of an implant  110  according to the present invention is shown. In general, implant  110  may be resiliently compressible or expandable such that the implant may support and or adjust to dynamic movement of the spine. As seen in  FIG. 11 , implant  110  is shown in relation to two adjacent spinous processes  5  between which the implant is implanted. Implant  110  generally comprises a main body  111  having at least one top end  112  and at least one bottom end  113 , a first posterior side  114  extending between the top and bottom end, and a second anterior side  115  extending from the top end  112  to bottom end  113 . At least a portion of each of the first and second sides  114 ,  115  is curved. In some embodiments, at least one of the first and second sides  114 ,  115  is curved in a convex direction (e.g. second side  115  in  FIG. 11 ) and at least one of the first and second sides  114 ,  115  is curved in a concave direction (e.g. the first side  114  in  FIG. 11 ). In operation, the curved configuration may function similar to a biasing member or spring such that implant  110  may be flexible or resiliently compressed or expanded in the cranial-caudal direction. Optionally, the main body  111  may contain one or more openings  116 . Opening(s)  116  may optionally be curved similar to the convex and concave directions of the first and second sides  114 ,  115  of the body as depicted in  FIG. 11 , and may provide or enhance flexibility of the implant. The material(s) from which the implant is made may also provide or enhance flexibility of the implant. For example, implant  110  may be made from a resiliently deformable material such that the implant may be resiliently compressible or expandable to support and or adjust to dynamic movement of the spine. In this regard, the shape and configuration of the implant may allow the implant to resiliently deform in the cranial-caudal direction and provide dynamic support between the adjacent spinous processes to accommodate extension and flexion of the spine. 
         [0098]    Embodiments according to the present invention may be positioned or implanted such that the body  111  is entirely between two spinous processes  5 , or as depicted in  FIG. 11 , one or both of the top  112  and bottom  113  ends of the body may overlap one or more sides of one or more of the spinous processes. In embodiments where one or both of the top and bottom ends overlap to the one or more of the sides of one or more of the spinous processes, the body  111  may have two top ends  112  (one on either side of a spinous process) and two bottom ends  113  (one on either side of a spinous process). Alternatively, the top and bottom ends of the implant may overlap with the spinous processes on the same side, or a second implant may optionally be implanted on the opposite side of the spinous processes. In certain embodiments, implant  110  may be secured in place by the methods described herein, which may include for example, connecting implant  110  to the spinous process through holes  8  in the implant. 
         [0099]    Referring to  FIG. 12 , another embodiment of an implant  120  according to the present invention is shown in relation to two adjacent spinous processes  5  between which the implant is implanted. In general, implant  120  may allow dynamic relative movement between adjacent spinous processes. Implant  120  is adapted and configured to be placed between adjacent spinous processes, and generally includes a top body  127  and a bottom body  128  rotatably interconnected at a rotation body  129 . The top body and bottom body may be of any formation so long as they can rotate as desired about the rotation body as desired for implantation and/or for flexion purposes after implantation. The rotation body may be for example, a ball and socket configuration. For example, the ball and socket configuration may allow implant  120  adjust to dynamic movement of the spine once the implant is inserted. In this regard, implant  120  may accommodate limited contraction and expansion of adjacent spinous processes in the cranial-caudal direction as well as relative movement in the medial-lateral direction and posterior-anterior direction to accommodate dynamic movement of the spine. In the cranial-caudal direction, implant  120  may have a maximum distraction distance (d) to support limited flexion of the spine. 
         [0100]    According to certain embodiments of the present invention one or both of the top and bottom bodies may overlap to the side of the spinous process. According to these embodiments, the top body  127  and/or the bottom body  128  may overlap on either side of a spinous process. Alternatively, the top body  127  and bottom body  128  overlap with the spinous processes on the same side, and a second implant may be optionally implanted on the opposite side of the spinous processes. In other embodiments, implant  120  may include saddle portions as described previously. 
         [0101]    According to methods of the present invention, the implant may be inserted between two adjacent spinous processes  5 , where the top body  127  and/or the bottom body  128  are rotated about the rotation body  129  (either towards or away from each other), such that the height (d) of the implant is not at its maximum. After the implant is positioned between spinous processes, the top body  127  and/or bottom body  128  may be rotated with respect to the rotation body  129  until the implant is positioned at a desired height (d). The implant may be locked or secured to the desired height or adapted to allow a certain flexibility or rotation about the rotation body  129 . In certain embodiments, implant  120  may be secured in place by the methods described herein, which may include for example, connecting implant  120  to the spinous process through holes  8  in the implant. 
         [0102]      FIGS. 13   a - b  depict another embodiment of an implant  130  according to the present invention in relation to two adjacent spinous processes  5  between which the implant is implanted. Similar to implant  110  described with respect to  FIG. 11 , implant  130  may be resiliently compressible or expandable such that the implant may support and or adjust to dynamic movement of the spine. As seen in  FIG. 13   a , implant  130  generally includes a body  131  having a top end  132  and a bottom end  133 , a first side  134  extending between the top and bottom end, and a second side  135  extending from the top to bottom end, where at least a portion of each of the first and second sides are curved.  FIG. 13  depicts embodiments where at least one of the first and second sides has a portion curved in a convex direction and at least one of the first and second sides has a portion curved in a concave direction. In operation, the curved configuration may function similar to a biasing member or spring such that implant  130  may be flexible or resiliently compressed or expanded in the cranial-caudal direction. The material(s) from which the implant is made may also provide or enhance flexibility of the implant. For example, implant  130  may be made from a resiliently deformable material such that the implant may be resiliently compressible or expandable to support and or adjust to dynamic movement of the spine. In this regard, the shape and configuration of the implant may allow the implant to resiliently deform in the cranial-caudal direction and provide dynamic support between the adjacent spinous processes to accommodate extension and flexion of the spine. 
         [0103]    Embodiments according to the present invention may comprise body  131  positioned entirely between the spinous processes, or as depicted in  FIG. 13 , one or both of the top  132  and bottom  133  ends of the body  131  may overlap to the side of the spinous process. In embodiments where one or both of the top and bottom ends overlaps to the side of the spinous process body  131  may have saddle portions  3  on the top and bottom ends of implant  130  wherein each saddle includes lateral saddle walls  6  (one on either side of a spinous process). A non-limiting example of such an embodiment is depicted in  FIG. 13   b , depicting two top saddle walls  6  on either side of a spinous process, and two bottom saddle walls  6  on either side of a spinous process. In an alternative embodiment, the top end  132  and bottom end  133  of implant  130  may overlap the spinous processes on the same side of the spinous process, and a second implant may be optionally implanted on the opposite side of the spinous processes. Implant  130  may be secured in place by any suitable methods described herein. 
         [0104]    Referring to  FIGS. 14   a - b,  another embodiment of an implant  140  according to the present invention is shown in relation to two adjacent spinous processes  5  between which the implant is implanted. Implant  140  is configured and adapted to be placed between adjacent spinous processes, and generally comprises a body  145  and a securing device  146 . The body  145  is positioned between the spinous processes  5 . The securing device  146  weaves through both the body  145  and the spinous processes (for example, as depicted in the front view  FIG. 14   b ) to maintain the body&#39;s position between the spinous processes. The securing device  146  may have a coupling device  147  to tighten securing device  146  or otherwise add tension to the device to secure implant  140  in position. 
         [0105]    The body  145  may be of any desirable shape or size such that it fits between the spinous processes, optionally, with portions thereof overlapping to the sides of the spinous processes (as depicted for example in  FIG. 14   b ). The body needn&#39;t contact either spinous process at any particular time, but may allow for space between the spinous process  5  and the body  145 . The body  145  may be made of any suitable material, but according to certain embodiments, the body  145  is more rigid than the securing device  146 . 
         [0106]    The securing device  146  may be in one or more pieces, components, and/or materials. Securing device  146  may pass through the body at one or more positions and through the spinous processes, at one or more positions, so long as the body is generally maintained between the spinous processes. 
         [0107]    Referring to  FIGS. 15   a - b,  another embodiment of an implant  150  according to the present invention is shown in relation to two adjacent spinous processes  5  between which the implant is implanted. Implant  150  is configured and adapted to be placed between adjacent spinous processes, and generally comprises a top body  151  and a bottom body  152  rotatably and/or linkingly connected. The top body  151  may have either a male or female fitting portion, and the bottom body  152  may have a corresponding opposite fitting portion. According to one embodiment shown in  FIG. 15   a , the top body  151  has a female fitting portion  153 , and the bottom portion has a male fitting portion  154 . The fitting portions may be of any configuration so long as they fit together. Similarly, the top body and bottom body may be of any formation so long as they fit together at the male/female portions. The male and female portions may optionally be attached to one another. Further the male and female portions may optionally be attached such that the top portion and bottom portion can rotate as desired about an attachment position for implantation purposes and/or for flexion purposes after implantation. The male and female portions may be for example, a tongue and groove configuration. For example, the tongue and groove configuration may allow implant  150  adjust to dynamic movement of the spine once the implant is inserted. In this regard, implant  150  may accommodate limited contraction and expansion of adjacent spinous processes in the cranial-caudal direction as well as relative movement in the posterior-anterior direction to accommodate dynamic movement of the spine. 
         [0108]    According to certain embodiments of the present invention one or both of the top and bottom bodies may overlap to the side of the spinous process as depicted in  FIG. 15   a . According to these embodiments, the top body  151  and/or the bottom body  152  may overlap on both sides of a spinous process (as shown for example, in  FIG. 15   b ). In embodiments where one or both of the top and bottom ends overlaps to the side of the spinous process, top and bottom bodies  151 ,  152  may have saddle portions  3  on the top and bottom ends of implant  150  wherein each saddle portion includes lateral saddle walls  6  (one on either side of a spinous process). A non-limiting example of such an embodiment is depicted in  FIG. 15   b , depicting two top saddle walls  6  on either side of a spinous process, and two bottom saddle walls  6  on either side of a spinous process. In an alternative embodiment, the top end  151  and bottom end  152  of implant  150  may overlap the spinous processes on the same side of the spinous process, and a second implant may be optionally implanted on the opposite side of the spinous processes. Implant  150  may be secured in place by any suitable methods described herein. 
         [0109]    Referring to  FIGS. 16-18 , additional embodiments of implants  160 ,  170 ,  180  according to the present invention are shown. Implants  160 ,  170 , and  180  may allow dynamic relative movement between adjacent spinous processes and generally include a top U-shaped body  163  configured to movingly engage a bottom U-shaped body  164 . Each U-shaped body has an open end  167  and a closed end  168 . The open ends  167  of the U-shaped bodies are configured such that spinous processes may fit within a space created thereby. The closed ends  168  of the U-shaped bodies are generally configured to be directed toward one another after implantation. The top and bottom U-shaped bodies may be directly or indirectly engaged to one another or they may simply contact one another directly or indirectly. For example, the top and bottom U-shaped bodies may be configured such that the closed ends  168  fit together directly as depicted in  FIG. 18  and may include one ore more indented portions  165  to mate or fit with an adjacent U-shaped body. The U-shaped bodies may movingly engage one another similar to a ball and socket configuration. In this regard, implants  160 ,  170 , and  180  may adjust to dynamic movement of the spine once the implant is inserted. For example, the implants may accommodate limited contraction and expansion of adjacent spinous processes in the cranial-caudal direction as well as relative movement in the medial-lateral direction and posterior-anterior direction to accommodate dynamic movement of the spine. In the cranial-caudal direction, the implants may have a minimum distraction distance to support limited extension of the spine. 
         [0110]    Indirect contact or attachment may occur for example, in embodiments where there are one or more intermediate bodies, such as intermediate body  172  of  FIG. 17 . The intermediate body  172  may be of any configuration that fits at least partially between the top and bottom U-shaped portions after insertion of the implant. According to certain embodiments, the intermediate body may be shaped such that it configures to the shape of the top and/or bottom U-shaped bodies. For example, in  FIG. 17 , the intermediate body  172  is shaped to fit within indented portions  165  provided in the top and bottom U-shaped bodies. The intermediate body  172  may be made of any material suitable for implantation into a mammalian patient and may be selected based on the desired function of the intermediate body. For example, the intermediate body  172  may be made of a polymer material that may be resiliently compressible in the cranial-caudal direction. 
         [0111]    Implants in accordance with the present embodiments may be secured in place by the methods described herein, which may include for example, connecting the implant to the spinous process through holes  8  in the implant as depicted for example in  FIG. 18 . Exemplary implants may be secured to spinous processes, by surface modifications to portions of the implant, such as modifications to surfaces of an inside surface  169  of the U-shaped bodies. Such surface modifications may include mechanical modifications to the surface (see e.g., ridges  171  in  FIG. 16 ) and/or one or more coatings. Such mechanical forces and/or surface modifications may be utilized in addition to, or in place of various other attachment methods described herein. 
         [0112]    According to certain methods of the present invention the top U-shaped portion  163  and the bottom U-shaped portion  164  may be inserted between two adjacent spinous processes together or separately. By way of non-limiting example, embodiments such as those depicted in  FIG. 16  may be inserted by a straight posterior insertion, or they may be inserted by positioning one U-shaped portion over a spinous process and thereafter rotating the other U-shaped portion over the other spinous process. Any intermediate bodies may be inserted before, substantially simultaneously with, or after insertion of the top and bottom U-shaped portions. 
         [0113]    Referring to  FIGS. 19-21 , additional embodiments of the invention for creating, increasing, or maintaining distraction between adjacent spinous processes are shown. Implants  190 ,  200 , and  210  depicted in  FIGS. 19-21  generally include a first body  191  having a male portion  193  and a second body  192  having a female portion  194 , wherein the male portion fits partially within the female portion. Upon inserting the male portion into the female portion, spaces are created above and below portions of the male portion that are not within the female portion. Adjacent spinous processes may fit within those spaces and a minimum distraction distance or space may be provided by the male portion. 
         [0114]    The male portion  193  may be part of the first body  191  (as depicted in  FIG. 19 ) or it may be one or more portions attached to the first body  191  (as depicted in  FIG. 21 ). The male portion  193  may be curved or tapered as depicted in  FIG. 20  such that the further it is inserted into the female portion, the greater the distraction between spinous processes. 
         [0115]    Methods of the present invention may include the following: inserting a first body  191  and a second body  192  of the implant on either side of two adjacent spinous processes; fitting the bodies together by inserting a male portion  193  of the first body  191  into a female portion  194  of the second body  192 ; and adjusting a depth of insertion to a desired depth depending for example, on the size of spinous processes, and/or the desired amount of distraction between the spinous processes. Methods of the present invention may further include securing the implant between adjacent spinous processes. 
         [0116]    Implants in accordance with the present embodiments may be secured by the methods described herein. According to certain embodiments, the first body  191  and the second body  192  may be attached to one another, for example, by a pin  195 , screw or other fastening device after insertion into a patient to secure the implant in position. Other fastening devices or methods may be used in place of or in addition to attaching the first body  191  to the second body  192  for example, by connecting the implant to one or both spinous processes or other portion(s) of the spine. 
         [0117]    Referring to  FIGS. 22-24  additional embodiments of the invention for creating, increasing, or maintaining distraction between adjacent spinous processes are shown, wherein the implants are not directly attached to either spinous process, but are attached to other portions of the spine  222 . 
         [0118]    As shown in  FIG. 22 , one embodiment of an implant  220  may include at least two stabilization devices  227 , which attach to a portion of the spine  222  and a distraction device  228 , which maintains a spinous process  5  in a desired position or range of positions with respect to the portions of the spine to which the stabilization devices  227  are attached. In one embodiment, distraction device  228  is an arcuate member that extends between the stabilization devices  227  and is configured to engage a portion of an adjacent spinous process. The stabilization devices  227  may be for example, screws. The distraction device  228  may be for example, a polymer material and may be more flexible or resilient than the stabilization devices  227 . In general, implant  220  may allow dynamic relative movement between adjacent spinous processes. In operation, the curved configuration may function similar to a biasing member or spring such that implant  220  may be flexible or resiliently compressed in the cranial-caudal direction to support and or adjust to dynamic movement of the spine. In this regard, the shape and configuration of the implant may allow the implant to resiliently deform in the cranial-caudal direction and provide dynamic support between the adjacent spinous processes to accommodate extension and flexion of the spine. 
         [0119]    As shown in  FIG. 23 , one embodiment of an implant  230  may be attached to at least two non-spinous process portions of the spine  222 . Implant  230  generally comprises a zig-zag-shaped configuration, but embodiments according to the present invention are not limited to such configurations. Embodiments may include any formation and/or be made of any material that provides a desired shape and degree of flexibility. In alternate embodiments, implants may be configured such that they do or do not contact one or both spinous processes upon insertion. Implant  230  may contact one or both spinous processes after insertion based on movement of the patient and/or movement of the spine. In operation, the zig-zag or curved configuration may function similar to a biasing member or spring such that implant  230  may be flexible or resiliently compressed or expanded in the cranial-caudal direction. The material(s) from which the implant is made may also provide or enhance flexibility of the implant. For example, implant  230  may be made from a resiliently deformable material such that the implant may be resiliently compressible or expandable to support and or adjust to dynamic movement of the spine. In this regard, the shape and configuration of the implant may allow the implant to resiliently deform in the cranial-caudal direction and provide dynamic support between the adjacent spinous processes to accommodate extension and flexion of the spine. 
         [0120]    As shown in  FIG. 24  one embodiment of an implant  240  generally comprises a main body  241  attached to at least one attachment device  242 . The attachment device  242  may be attached to at least two non-spinous process portions of the spine  222 . In one variation of the embodiment depicted in  FIG. 24 , attachment devices  242  may have a folding configuration, which may assist in insertion and/or in flexibility or movement of the implant  240  after insertion. 
         [0121]    Implant bodies  241  may be in any configuration. According to certain embodiments, implant body  241  may include rigid material(s) and the attachment device  242  may be either rigid or at least partially flexible or maneuverable. In certain embodiments, implant body  241  may be configured such that it may or may not contact one or both spinous processes upon insertion. For example, in certain variations, implant body  241  may contact one or both spinous processes after insertion based on movement of the patient and/or movement of the spine. 
         [0122]    Referring to  FIGS. 25-26 , additional embodiments of implants according to the invention are shown for creating, increasing, or maintaining distraction between adjacent spinous processes. Implants  250  generally include a body  252  and one or more straps  253 . The strap(s)  253  are configured such that they wrap around one or both spinous processes, and can maintain the position of the body  252  with respect to the spinous processes. Maintaining the position of the body  252  with respect to the spinous processes, does not require that the body not move at all, but rather means that the body does not move so far away from between the spinous processes that it does not perform the function of maintaining a distraction between the spinous processes. 
         [0123]    Referring to  FIGS. 27   a - b,  another embodiment of an implant  270  according to the invention is shown for creating, increasing, or maintaining distraction between adjacent spinous processes. Implant  270  generally comprises a center body  274  having at least two male portions  276 , and at least two outside bodies  275  having at least two female portions  277 . The male and female portions fit together to define a top space above the center body  274 , and a bottom space below the center body  274 . Two adjacent spinous processes fit within the top and bottom spaces. The center and outside bodies, and the male and female portions may be of any configuration that defines adequate top and bottom spaces in which to fit the spinous processes. According to certain embodiments, the center body  274  is made of a softer material than the outside bodies  275 . 
         [0124]    As shown in  FIG. 27   b , the male portions  276  may be ribbed. Ribbing may assist in maintaining the male portions  276  within the female portions  277 . 
         [0125]    Methods of the present invention may include the following: inserting a center body  274  between two adjacent spinous processes and inserting at least two outside bodies on either side of the adjacent spinous processes; fitting the bodies together by inserting the male portions  276  of the center body  274  into the female portions  277  of the outside bodies  275 ; and adjusting a depth of insertion of the male portions into the female portions to a desired depth depending for example, on the size of spinous processes, and/or the desired amount of distraction between the spinous processes. Methods of the present invention may further include securing the implant between adjacent spinous processes. 
         [0126]    Implants in accordance with the present embodiments may be secured by the methods described herein. According to certain embodiments, the center body  274  and one or both of the outside bodies  275  may be attached to one another, for example, by a pin, screw or other fastening device after insertion into a patient to secure the implant in position. Other fastening devices or methods may be used in place of or in addition to attaching the center body  274  to one or both outside bodies  275 , for example, by connecting the implant to one or both spinous processes or other portion(s) of the spine. 
         [0127]    Referring to  FIGS. 28-33 , another embodiment of an implant  300  according to the present invention is shown for creating, increasing, or maintaining distraction between adjacent spinous processes. Implant  300  is adapted and configured to be placed between adjacent spinous processes. As shown in  FIG. 28 , implant  300  is generally H-shaped or anvil shaped with a saddle portion or central support portion  302  extending laterally along axis  303  between lateral end portions  304 ,  306 . Support portion  302  comprises a top or proximal support surface  308  and a bottom or distal support surface  310  spaced longitudinally apart by a height or distance  312 , which generally corresponds to the desired or predetermined distance for distraction or spacing of two adjacent spinous processes. As best seen on  FIG. 28 , in one embodiment, end portions  304 ,  306  partially protrude beyond the front and back surfaces  309 ,  311  of support portion  302  thereby creating a slight indentation along the front and back or anterior and posterior of central portion  302 . As described in more detail below, when implant  300  is inserted laterally between adjacent spinous processes, the processes are initially dilated a distance slightly greater than the depth  314  of central portion  302 . In this regard, in a first implantation position the spinous processes settle or center adjacent the indented region of central support portion  302 , as shown for example in  FIG. 40 . In addition, when implant  300  is in a second implantation position, as shown in  FIGS. 41-42 , the indentations on the front and back are configured and dimensioned to avoid contact with the dura. 
         [0128]    End portions  304 ,  306  extend generally perpendicular to support portion  302  and generally extend longitudinally beyond support surfaces  308 ,  310  and generally form wing-like structures on the lateral ends of implant  300 . End portion  304  extends longitudinally along axis  305  and end portion  306  extends longitudinally along axis  307 . In one embodiment, axes  305  and  307  are generally perpendicular to axis  303 . In another embodiment, axes  303 ,  305 , and  307  are coplanar. End portions  304 ,  306  are spaced laterally apart by a width distance  315 , which generally corresponds to the desired or predetermined distance for accommodating the width of the spinous processes. The inner surfaces or walls of end portions  304 ,  306  may contact or engage the lateral sides of the spinous processes when the implant is implanted. In this regard, end portions  304 ,  306  are configured and dimensioned to generally prevent or limit lateral movement of the implant when the implant is implanted. In one variation, the space between end portions  304 ,  306  may be angled toward the center of implant to align the spinous processes with respect to central portion  302 . According to one aspect of the present invention, multiple implants of varying widths  315  may be provided in a kit for appropriate selection and installation by a surgeon. 
         [0129]    In one embodiment, end portion  304  generally comprises a cylindrical, bullet, anvil or horn shape extending longitudinally from a rounded bottom or distal end  316  to a narrower tip, nipple, or bull nose shaped top or proximal end  318 . As best seen when viewed from the front as in  FIG. 29 , in one embodiment, the outer lateral surface portion  320  of end portion  304  is curved laterally outward from bottom end  316  to a point adjacent top end  318 . In this regard, the curved aspect resembles a horn or boot and facilitates a combined lateral and rotational or pivotal insertion between spinous processes as the curved profile provides clearance during in-situ rotation or pivoting about an axis extending in the anterior-posterior direction through end portion  304  adjacent the bottom end  316 . In operation, implant  300  may be pivoted about bottom end  316  during lateral insertion such that end portion  304  is rotated from a lateral or horizontal position (shown in  FIG. 39 ) to an upright or longitudinal position (shown in  FIG. 40 ). According to another aspect of an embodiment of the invention, a rounded or curved inner transition  322  may be provided between inner lateral surface  324  of end portion  304  and proximal support surface  308  of support portion  302 . Referring to FIG.  33 , in one embodiment end portion  304  may be tapered or increase in thickness along its length such that the proximal tip  318  is narrower or thinner than the base or bottom end  316  when viewed from the end. At its thickest point, front surface portion  323  of end  304  is spaced from back surface portion  325  of end  304  by a distance  327 . In this regard, the tapered feature acts or performs in a cam-like manner to translate the lateral or pivotal force to separate the spinous processes in the longitudinal or cranial-caudal direction as the implant is inserted. In alternate embodiments, outer lateral surface or portion  320  of end portion  304  may have differing shapes or curves that may facilitate lateral and/or pivotal insertion and/or provide additional mechanical advantage to distract the spinous processes in operation. 
         [0130]    Referring to  FIG. 30 , in one variation, support portion  302  has a generally rectangular cross-section with a height  312  and a depth  314 . In one embodiment, height  312  is greater than depth  314 . In one variation, height  312  is about 2 mm greater than depth  314 . In alternate embodiments, any suitable range of heights and depths may be utilized. In one embodiment, a center locating pin  326  may be positioned in the center of central portion  302  extending in a longitudinal direction and a lateral end locating pin  329 , best seen in  FIGS. 29 and 31 , may extend perpendicular to axis  303  in an anterior-posterior direction to facilitate the location of implant  300  using fluoroscopic devices known to those skilled in the art. Locating pins  326 ,  329  may be made from any known radio-opaque material known to those skilled in the art, including, but not limited to, tantalum. 
         [0131]    As best seen in  FIGS. 29 and 32 , lateral end portion  306  generally comprises a thin wall or plate having a uniform thickness  328 . As shown in  FIG. 32 , when viewed from the end, end portion  306  has a generally arcuate, bent, or teardrop shaped top or proximal end  330  and a rounded bottom or distal end  332  and a hexagonal opening  333  to accommodate or engage an insertion tool  424  (shown in  FIGS. 39-41  and  50 - 52 ). In alternate embodiments, any suitable attachment means known to those skilled in the art may be utilized to engage insertion tool  424  with implant  300 , including, but not limited to, a threaded engagement. In one embodiment, opening  333  may extend through the entire body of the implant, creating a cannulated body. The arcuate proximal end  330  is configured and dimensioned to accommodate positioning between spinous processes such that the anterior cutout or inner curve  334  of end  330  is shaped and sized to contact the lamina upon installation. Anterior curve  334  in end portion  306  facilitates anterior positioning as it allows implant  300  to wrap around, accommodate or engage the lamina upon installation in an anterior position with respect to the spinous processes. In another embodiment, a similar sized and shaped anatomical anterior cutout may be provided on first end portion  304 . According to one embodiment, implant  300  is configured to be positioned in a final installation location anterior the spinous processes. In this regard, in one embodiment implant  300  may be maintained or held in the installed position without additional fixation devices. As best seen in  FIG. 29 , distal end  332  protrudes longitudinally beyond distal support surface  310  in the distal direction. In one variation, the protruding distal end  332  of second end portion  306  is configured to prevent over-insertion or over rotation of implant  300  when the implant is positioned into the first installation position. In one embodiment, a transition, ramp, or chamfer  336  is provided between end portion  306  and support portion  302 . In another variation chamfer  336  comprises a generally linear transition or pyramid-like step or increase from support portion  302  to end portion  306 . In general, chamfer  336  functions as a ramp or transition to facilitate positioning or centering of the spinous process adjacent support surfaces  308 ,  310 . 
         [0132]    In certain variations of the aforementioned embodiment, implant  300  may be attached to one or both of the adjacent spinous processes to secure the implant. By way of non-limiting example, the implant may have one or more openings  335  which permit the attachment of the implant to one or both spinous processes by one or more fastening devices, such as, for example, a suture or screw. In another embodiment, one or more additional openings may be provided on the opposite end portion to accommodate a fixation or fastening device. 
         [0133]    In one embodiment, at least a portion of the front and back surfaces comprise textured, striated, or grooved portion(s)  337 . In this embodiment, portions  337  comprise multiple lateral grooves  339  extending laterally along a portion of the front and back surfaces of end portions  304 ,  306 . In operation, grooved portions  337  may prevent movement of implant  300  in any non-parallel direction with respect to any portion of the spinous processes that it may contact upon implantation. In this regard, groove portions  337  facilitate mechanical fixation with respect to the spinous processes. 
         [0134]      FIGS. 34-36  depict alternate implants  400 ,  405 ,  410  according to the present invention adapted to be placed between adjacent spinous processes. Implants  400 ,  405 ,  410  are similar to implant  300  of  FIGS. 28-33 , except that the amount of lateral grooves may be more or less than lateral grooves  339  of implant  300 . Referring to  FIG. 34 , in one embodiment, implant  400  may comprise more grooves and as shown in  FIG. 36 , in another embodiment, implant  410  may be free from grooves altogether. Referring to  FIG. 35 , according to one embodiment, implant  405  may comprise grooves along a majority of the front and back surfaces and may be positioned at an angle. According to another aspect of the invention, implant  405  may comprise indented regions  407 ,  409  along the central support portion to accommodate or center a portion of the spinous processes therein. In one variation, proximal indented region  407  may have a different width than distal indented region  409 . In this regard, the differing widths may accommodate differing contact widths of adjacent processes on the posterior and distal sides upon implantation. According to one aspect of the present invention, multiple implants of varying groove arrangements may be provided in a kit for appropriate selection and installation by a surgeon. 
         [0135]    Referring to  FIGS. 37-38 , another implant  420  according to the present invention is shown. Implant  420  is similar to implant  300  described above, except that central portion  422  has a circular cross-section with a generally constant diameter  423  along its lateral axis. In operation, diameter  423  provides a constant distraction distance and once the implant is implanted and after the spinous processes are positioned adjacent central portion  422  of the implant  420 , the implant may maintain the spinous processes in a distracted or spaced condition, for example where the distraction distance or diameter  423  of implant  420  is greater than a pre-implantation distance between the spinous processes. According to one aspect of the present invention, multiple implants having varying cross-sectional shapes and sizes may be provided in a kit for appropriate selection and installation by a surgeon. For example, in certain kits according to the invention, implants may be provided with heights ranging from about 8 mm to about 16 mm in 1 mm increments, and widths ranging from about 12 mm to about 20 mm in 1 mm increments. In some kits according to the invention, implants may be provided having a depth from about 6 mm to about 14 mm. 
         [0136]    Referring to  FIGS. 39-42  and  50 - 52 , according to methods of the present invention, implants  300 ,  400 ,  410 ,  420  may be inserted between two adjacent spinous processes  5  using an insertion tool  424 . In one embodiment, as best seen in  FIG. 51 , insertion tool  424  comprises a shaft  426  with a tip  428  extending generally at an angle  427  with respect to shaft  426 . In one variation, angle  427  may be between about 100 and 135 degrees. As explained above, in one variation, tip  428  comprises a hexagonal perimeter sized and shaped to engage a similarly shaped opening on the implant, such as opening  333  shown in  FIG. 32 . In alternate embodiments, any suitable attachment means known to those skilled in the art may be utilized to engage insertion tool  424  with implant  300 , including, but not limited to, a threaded engagement. In one embodiment of a method according to the invention, as shown for example in  FIG. 39  for implant  300 , a portion of end portion  304  may contact at least one of the adjacent spinous processes. In one variation, the implant may be inserted laterally such that the bull nose tip or distal end  318  of end portion  304  is inserted between adjacent spinous process and the implant may be laterally advanced and pivoted to dilate or distract the processes until the implant is positioned into or adjacent the saddle or support portion  302  of the implant, as shown in  FIG. 40 . As shown in  FIG. 40 , the adjacent spinous processes may contact or engage front and back surfaces  309 ,  311  of support portion  302 . Subsequently, in another embodiment, implant  300  may be rotated 90 degrees to further distract the spinous process until the two adjacent spinous processes engage or contact the top and bottom support surfaces  308 ,  310 , as shown in  FIG. 41 . After insertion tool  424  is removed, implant  300  is positioned in a final implantation position as shown in  FIG. 42 . 
         [0137]    As explained above with respect to other embodiments, in this embodiment the implant itself may serve to dilate or distract the spinous processes as it is being inserted and/or after insertion. For example, the implant may be initially inserted laterally and pivotally between the compressed adjacent spinous processes as shown in  FIG. 39 . In one embodiment, the supraspinous ligament need not be removed. In operation, lateral end portion  304  of implant  300 , engages the adjacent spinous processes as the implant is inserted laterally and pivoted to act or perform in a cam-like manner to translate the lateral/pivotal force to separate the spinous processes in the longitudinal or cranial-caudal direction as the implant is inserted. For example, in an initial pre-implantation condition, the adjacent spinous processes may be in an initial compressed state such that the initial space or longitudinal distance between the processes may be equal to or smaller than distance  312  of implant  300 . During lateral and pivotal insertion of implant  300 , as shown in  FIG. 39 , proximal tip  318  of lateral end portion  304  of the implant may contact one or both of the spinous processes  5  and may initially distract the processes. As the implant is inserted further between the spinous processes and pivoted, as explained above, the tapered surface portions  323 ,  325  may distract the spinous processes further apart from one another, until the implant is positioned into a first implantation position ( FIG. 40 ) and the spinous processes are fitted adjacent the front and back surfaces  309 ,  311  of saddle or support portion  302  of the implant. In one embodiment, implant  300  may be rotated about 90 degrees about the lateral axis  303  from the horizontal or lateral position shown in  FIG. 40  to the vertical or longitudinal position shown in  FIG. 41  and the spinous processes are fitted into the upper and lower surfaces of saddle or support portion  302  of the implant separated by distraction distance  312 . In this regard, in one embodiment, shaft  426  of insertion tool  424  is generally movable within the realm of the incision created between about 45 degrees on both sides of a lateral plane  429 . After insertion tool  424  is removed, implant  300  is positioned in a final implantation position as shown in  FIG. 42 . Once the implant is implanted and after the spinous processes  5  are fitted into the saddle or support portion  302  of implant  300 , the implant may maintain the spinous processes in a distracted or spaced condition, for example where the distance  312  of the implant is greater than a pre-implantation distance between the spinous processes. 
         [0138]    According to one embodiment of a method according to the invention for inserting implant  300 , the adjacent first and second spinal processes may be accessed by various methods known by practitioners skilled in the art, for example, by accessing the spinous processes from at least one lateral side/unilateral, bilateral, or midline posterior approach. Certain methods of the present invention include removing or dilating any interspinous ligaments in a position in which the implant is to be placed in the patient prior to inserting the implant. In one exemplary embodiment, a dilation tool  430  as shown in  FIGS. 43-44  may be utilized to dilate interspinous ligaments. For example, when using a unilateral approach, dilation tool  430  is particularly well suited to access and/or dilate ligaments on the side of the spinous processes opposite the incision. The bullet or horn shaped end portion  304  further facilitates insertion through the dilation. In this regard, according to certain methods of the invention, a unilateral approach may be used to install implant  300  without removal of the supraspinous ligament. 
         [0139]    Other embodiments of methods of the present invention may include dilating or distracting the spinous processes apart from one another before sizing and/or before inserting the implant. In one exemplary embodiment, a distraction tool  440  as shown in  FIGS. 45-46  may be utilized to distract spinous processes. In operation, the distal tips  442  of distraction tool  440  may be inserted between adjacent processes and the handles  444  on the proximal end of the tool may be compressed to cause distal tips  442  to spread apart. As is known in the art, a compression dial  446  and measuring bar  448  may be provided to facilitate measurable and/or precise distraction. 
         [0140]    In certain methods of installation, it may be desired or necessary to reduce a portion of one or more facet joints adjacent the implantation locale. For example, in some patients inflamed or enlarged facet joints may impede or hinder a surgeon&#39;s ability to install an implant between the spinous processes. In one exemplary embodiment, a reamer tool  460  as shown in  FIG. 47-48  may be utilized in combination with a guide sleeve  480 , shown in  FIG. 49 , to remove, ream, or otherwise reduce at least a portion of the enlarged facet. In one embodiment, reamer  460  comprises a plurality of fluted cutting surfaces  462  adjacent its distal tip  464 . In one variation, cutting surfaces  462  extend radially around distal tip  464 . In operation, guide sleeve  480  may be inserted into the patient and the distal tip  482  of the guide sleeve  480  is configured and dimensioned to fit on or engage a bulbous facet to be treated. Reamer tool  460  may then be inserted into sleeve  480  such that distal tip  482  contacts the facet and rotation of reamer tool  460  grinds, cuts, reams or otherwise removes material from the facet joint. 
         [0141]    In another embodiment of a method according to the invention, sizing of the space between adjacent spinous processes (for example using trials) may be performed. In one exemplary embodiment, a trial  490  and insertion tool  424 , shown in  FIGS. 50-52 , may be utilized to size the space between adjacent processes. In one variation, trial  490  comprises multiple longitudinal indentations or markings  492  on at least a portion of central portion  494 . Markings  492  provide visual indication when viewed under fluoroscopy of the width of the spinous processes and facilitate the surgeon&#39;s selection of an appropriately sized implant. Similarly, the appropriate diameter of central portion  494  of trial  490  may be selected to gauge the amount of distraction desired. In this regard, the spacing of the spinous processes may be viewed under fluoroscopy to facilitate the surgeon&#39;s selection of an appropriately sized implant. Finally, an implant of the appropriate size may be inserted between the adjacent spinous processes. 
         [0142]    While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations can be made thereto by those skilled in the art without departing from the scope of the invention.