Abstract:
Systems and methods for placing spinal implants within an intervertebral region. In some embodiments, a surgical positioning tool may be provided that allows for access to an implantation site to be gained along a first axis, and then allows a spinal implant to be repositioned from the first axis to a second axis at an angle with respect to the first axis. The spinal implant may, in some embodiments, comprise a recess comprising two adjacent bars configured to engage elements of the surgical positioning tool to allow for the aforementioned repositioning.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority of U.S. patent application Ser. No. 12/396,761, filed on Mar. 3, 2009 and titled “SURGICAL POSITIONING ASSEMBLY AND ASSOCIATED SPINAL IMPLANT DEVICE AND SURGICAL METHODS,” which claims the benefit of U.S. Provisional Patent Application No. 61/033,079, filed on Mar. 3, 2008 and titled “POSTERIOR LATERAL POSITIONING DEVICE AND ASSOCIATED IMPLANT DEVICE POSITIONING METHODS.” Both of the aforementioned patent applications are hereby incorporated by reference herein in their entireties. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates generally to a surgical positioning assembly that is used to place a spinal implant device or the like within an intervertebral space or the like of a patient and associated surgical methods. Advantageously, the surgical positioning assembly allows access to the implantation site to be gained along a first axis, with the implant device subsequently being placed along a second axis that is disposed at an angle or substantially perpendicular to the first axis via the actuation of the surgical positioning assembly. Thus, for example, a surgeon may use an anterior or posterior approach to place an implant device laterally, or vice versa. 
       BACKGROUND 
       [0003]    Interbody fusion is a surgical spinal procedure that places a porous metallic, plastic, or composite cage device and/or bone graft between adjacent vertebrae in the area usually occupied by an intervertebral disc, maintaining spinal alignment and disc height. Anterior lumbar interbody fusion (ALIF) is a spinal fusion procedure that utilizes an anterior (i.e. front) approach through the abdomen region to fuse adjacent vertebrae of the lumbar spine. Likewise, posterior lumbar interbody fusion (PLIF) is a spinal fusion procedure that utilizes a posterior (i.e. rear) approach through the back region to fuse adjacent vertebrae of the lumbar spine. 360-degree fusion and other similar procedures are a combination/variation of ALIF and PLIF. The intervertebral disc is removed using appropriate rasping and grasping tools and replaced with a cage device and/or bone graft after appropriate distraction and spacing tools are used to restore the normal height of the intervertebral space. ALIF is preferred when either one or multiple spinal levels are being fused and one or multiple intervertebral discs must be removed, and may be performed in conjunction with a posterior decompression (i.e. a laminectomy) and/or the placement of stabilizing instrumentation (i.e. screws and rods, plates, etc.). Because during ALIF the spinal nerves and other neurologic structures do not have to be retracted, wide access to the intervertebral space(s) of interest is provided without unacceptable risk of neurologic injury. ALIF is used to treat a variety of painful spinal conditions, such as spondylolisthesis and degenerative disc disease, among others. PLIF is also preferred when either one or multiple spinal levels are being fused and one or multiple intervertebral discs must be removed, and may be performed in conjunction with the placement of stabilizing instrumentation (i.e. screws and rods, plates, etc.). PLIF is also used to treat a variety of painful spinal conditions, such as spondylolisthesis and degenerative disc disease, among others. In either and all cases, it is often desirable to place an implant device laterally, that is, at an angle or substantially perpendicular to the anterior or posterior access axes, or vice versa. 
         [0004]    Conventional cage devices typically include some sort of retention mechanism to hold them securely in the intervertebral space. Such retention mechanisms include biting and locking structures that engage the endplate(s) of the vertebral body or bodies of interest, screw assemblies that engage the vertebral body or bodies of interest, plate structures that engage the vertebral body or bodies of interest, etc. All of these cages and retention mechanisms, however, suffer from the shortcomings that they are difficult to place, difficult to deploy, and/or tend to allow the associated cage device and/or bone graft to shift over time and thus fail to adequately maintain the normal height of the intervertebral space, for example. Again, for these and other reasons, it is often desirable to place an implant device laterally, that is, at an angle or substantially perpendicular to the anterior or posterior access axes, or vice versa. 
       SUMMARY 
       [0005]    Again, in various exemplary embodiments, the present invention provides a surgical positioning assembly that is used to place a spinal implant device or the like within an intervertebral space or the like of a patient and associated surgical methods. Advantageously, the surgical positioning assembly allows access to the implantation site to be gained along a first axis, with the implant device subsequently being placed along a second axis that is disposed at an angle or substantially perpendicular to the first axis via the actuation of the surgical positioning assembly. Thus, for example, a surgeon may use an anterior or posterior approach to place an implant device laterally, or vice versa. 
         [0006]    In one exemplary embodiment, the present invention provides a surgical positioning assembly operable for positioning a surgical implant device within an implantation site in the body of a patient through an incision and/or portal, including: a grip operable for holding the surgical positioning assembly along a first axis through incision and/or portal; a retention mechanism operable for selectively coupling the surgical implant device to the grip and holding the surgical implant device substantially along the first axis; and a pivot/rotation mechanism operable for one or more of selectively pivoting and selectively rotating the surgical implant device relative to the grip until it is substantially along a second axis that is one or more of disposed at an angle to and rotated relative to the first axis. Optionally, the retention mechanism includes one or more rod structures including one or more of a hook structure and a saddle structure. Optionally, the surgical implant device includes one or more bar structures that selectively engage the one or more rod structures via the one or more hook structures and saddle structures. Optionally, the pivot/rotation mechanism includes one or more rod structures including one or more of a hook structure and a saddle structure. Optionally, the surgical implant device is an intervertebral cage. 
         [0007]    In another exemplary embodiment, the present invention provides a surgical implant device for implantation within an implantation site in the body of a patient through an incision and/or portal, including: one or more retention structures operable for selectively coupling the surgical implant device to a retention mechanism of a surgical positioning assembly and holding the surgical implant device substantially along a first axis associated with the surgical positioning assembly; and one or more pivot/rotation structures operable for selectively engaging a pivot/rotation mechanism of the surgical positioning assembly and by which the surgical implant device is one or more of selectively pivoted and selectively rotated relative to the surgical positioning assembly until it is substantially along a second axis associated with the surgical positioning assembly that is one or more of disposed at an angle to and rotated relative to the first axis. Optionally, the retention mechanism of the surgical positioning assembly includes one or more rod structures including one or more of a hook structure and a saddle structure. Optionally, the one or more retention structures include one or more bar structures that selectively engage the one or more rod structures of the surgical positioning assembly via the one or more hook structures and saddle structures. Optionally, the pivot/rotation mechanism of the surgical positioning assembly includes one or more rod structures including one or more of a hook structure and a saddle structure. Optionally, the one or more pivot/rotation structures include one or more bar structures that selectively engage the one or more rod structures of the surgical positioning assembly via the one or more hook structures and saddle structures. Optionally, the surgical implant device is an intervertebral cage. 
         [0008]    In a further exemplary embodiment, the present invention provides a surgical method for positioning a surgical implant device within an implantation site in the body of a patient through an incision and/or portal using a surgical positioning assembly, including: disposing the surgical positioning assembly and surgical implant device through the incision and/or portal and adjacent to the implantation site along a first axis; actuating the surgical positioning assembly to pivot/rotate the surgical implant device relative to the surgical positioning assembly and into the implantation site along a second axis that is disposed one or more of at an angle to, substantially perpendicular to, and rotated with respect to the first axis; and actuating the surgical positioning assembly to disengage the surgical implant device from the surgical positioning assembly. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The present invention is illustrated and described herein with reference to the various drawings, in which like reference numbers are used to denote like assembly/device components and/or method steps, as appropriate, and in which: 
           [0010]      FIG. 1  is a perspective view illustrating one exemplary embodiment of the surgical positioning assembly and spinal implant device of the present invention, the surgical positioning assembly and spinal implant device illustrated in a disassembled state; 
           [0011]      FIG. 2  is a partial cross-sectional view illustrating the surgical positioning assembly and spinal implant device of  FIG. 1 , the surgical positioning assembly and spinal implant device illustrated in an assembled, but undeployed, state; 
           [0012]      FIG. 3  is another partial cross-sectional view illustrating the surgical positioning assembly and spinal implant device of  FIGS. 1 and 2 , the surgical positioning assembly and spinal implant device illustrated in an assembled, and deployed, state; and 
           [0013]      FIG. 4  is a flowchart illustrating one exemplary embodiment of the surgical positioning assembly and spinal implant device method of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Again, in various exemplary embodiments, the present invention provides a surgical positioning assembly that is used to place a spinal implant device or the like within an intervertebral space or the like of a patient and associated surgical methods. Advantageously, the surgical positioning assembly allows access to the implantation site to be gained along a first axis, with the implant device subsequently being placed along a second axis that is disposed at an angle or substantially perpendicular to the first axis via the actuation of the surgical positioning assembly. Thus, for example, a surgeon may use an anterior or posterior approach to place an implant device laterally, or vice versa. 
         [0015]    Referring to  FIG. 1 , in one exemplary embodiment, the present invention provides a surgical positioning assembly  10  and a spinal implant device  12 . In the most broad sense, the surgical positioning assembly  10  is operable for accessing an implantation site along a first axis, with the spinal implant device  12  subsequently being placed along a second axis that is disposed at an angle or substantially perpendicular to the first axis via the actuation of the surgical positioning assembly  10 . In the most narrow sense, the spinal implant device  12  is an intervertebral cage or the like and is configured and sized accordingly. However, it will be readily apparent to those of ordinary skill in the art that the surgical positioning assembly  12  may be used to place any suitable implant device within any suitable implantation site, intervertebral cage or non-intervertebral cage/spinal or non-spinal, and the first and second axes along which access and placement are carried out may be those associated with any suitable surgical approach, provided that the second axis is disposed at an angle to, substantially perpendicular to, and/or simply rotated with respect to the first axis via the actuation of the surgical positioning assembly  12 . 
         [0016]    In this exemplary embodiment, the spinal implant device  12  consists of a biocompatible structure  14  that defines a plurality of openings  15  in which a bone graft or the like may be placed, representing an intervertebral cage or the like. Thus, the spinal implant device  12  has a rounded prismatic or other suitable shape, and has a thickness on the order of millimeters to centimeters. The spinal implant device  12  includes a draw bar  16  and a pivot bar  18  by which the spinal implant device  12  is grasped and pivoted by and relative to the surgical positioning assembly  10 . Again, the spinal implant device  12  may include any suitable structures by which it is grasped and pivoted and/or rotated by and relative to the surgical positioning assembly  10  upon the actuation of the surgical positioning assembly  10 . 
         [0017]    In this exemplary embodiment, the surgical positioning assembly  10  consists of an annular grip  20  by which it is positioned and held in an incision site, a partially threaded rod  22  disposed through the annular grip  20 , and a draw knob  24  attached to one end of the partially threaded rod  22 . The other end of the partially threaded rod  22  terminates in a draw rod  26  and hook structure  28 . The hook structure is configured and sized to selectively retain the draw bar  16  of the spinal implant device  12 . The surgical positioning assembly  10  also includes a pivot rod  30  attached to the annular grip  20 , the pivot rod  30  terminating in a saddle structure  32  that is configured and sized to selectively retain the pivot bar  18  of the spinal implant device  12 . In operation, the draw knob  24  is selectively actuated, causing the partially threaded rod  22 , the draw rod  26 , and the hook structure  28  to recede towards/into the annular grip  20 , thereby pulling the draw bar  16 . This causes the spinal implant device  12  to pivot about the pivot bar  18  disposed in the saddle structure  32 , which is stationary. The draw knob  24  or another mechanism may be used to disengage the surgical positioning assembly  10  from the spinal implant device  12  once it is pivoted/rotated and placed. Again, the surgical positioning assembly  10  may include any suitable structures by which it grasps and pivots and/or rotates the spinal implant device  12  upon the actuation of the surgical positioning assembly  10 . 
         [0018]    Referring to  FIG. 2 , again, the spinal implant device  12  consists of a biocompatible structure  14  that defines a plurality of openings  15  in which a bone graft or the like may be placed, representing an intervertebral cage or the like. Thus, the spinal implant device  12  has a rounded prismatic or other suitable shape, and has a thickness on the order of millimeters to centimeters. The spinal implant device  12  includes a draw bar  16  and a pivot bar  18  by which the spinal implant device  12  is grasped and pivoted by and relative to the surgical positioning assembly  10 . 
         [0019]    The surgical positioning assembly  10  consists of an annular grip  20  by which it is positioned and held in an incision site, a partially threaded rod  22  disposed through the annular grip  20 , and a draw knob  24  attached to one end of the partially threaded rod  22 . The other end of the partially threaded rod  22  terminates in a draw rod  26  and hook structure  28 . The hook structure is configured and sized to selectively retain the draw bar  16  of the spinal implant device  12 . The surgical positioning assembly  10  also includes a pivot rod  30  attached to the annular grip  20 , the pivot rod  30  terminating in a saddle structure  32  that is configured and sized to selectively retain the pivot bar  18  of the spinal implant device  12 . In operation, the draw knob  24  is selectively actuated, causing the partially threaded rod  22 , the draw rod  26 , and the hook structure  28  to recede towards/into the annular grip  20 , thereby pulling the draw bar  16 . This causes the spinal implant device  12  to pivot about the pivot bar  18  disposed in the saddle structure  32 , which is stationary. The draw knob  24  or another mechanism may be used to disengage the surgical positioning assembly  10  from the spinal implant device  12  once it is pivoted/rotated and placed. 
         [0020]    Referring to  FIG. 3 , again, the spinal implant device  12  consists of a biocompatible structure  14  that defines a plurality of openings  15  in which a bone graft or the like may be placed, representing an intervertebral cage or the like. Thus, the spinal implant device  12  has a rounded prismatic or other suitable shape, and has a thickness on the order of millimeters to centimeters. The spinal implant device  12  includes a draw bar  16  and a pivot bar  18  by which the spinal implant device  12  is grasped and pivoted by and relative to the surgical positioning assembly  10 . 
         [0021]    The surgical positioning assembly  10  consists of an annular grip  20  by which it is positioned and held in an incision site, a partially threaded rod  22  disposed through the annular grip  20 , and a draw knob  24  attached to one end of the partially threaded rod  22 . The other end of the partially threaded rod  22  terminates in a draw rod  26  and hook structure  28 . The hook structure is configured and sized to selectively retain the draw bar  16  of the spinal implant device  12 . The surgical positioning assembly  10  also includes a pivot rod  30  attached to the annular grip  20 , the pivot rod  30  terminating in a saddle structure  32  that is configured and sized to selectively retain the pivot bar  18  of the spinal implant device  12 . In operation, the draw knob  24  is selectively actuated, causing the partially threaded rod  22 , the draw rod  26 , and the hook structure  28  to recede towards/into the annular grip  20 , thereby pulling the draw bar  16 . This causes the spinal implant device  12  to pivot about the pivot bar  18  disposed in the saddle structure  32 , which is stationary. The draw knob  24  or another mechanism may be used to disengage the surgical positioning assembly  10  from the spinal implant device  12  once it is pivoted/rotated and placed. 
         [0022]    Referring to  FIG. 4 , in one exemplary embodiment, the surgical method  40  of the present invention includes disposing the surgical positioning assembly  10  ( FIGS. 1-3 ) and spinal implant device  12  ( FIGS. 1-3 ) through an incision and adjacent to the implantation site of interest along a first axis (Block  42 ). Next, the surgical positioning assembly  10  is actuated to pivot/rotate the spinal implant device  12  relative to the surgical positioning assembly  10  and into the implantation site of interest along a second axis that is disposed at an angle to, substantially perpendicular to, and/or simply rotated with respect to the first axis (Block  44 ). Finally, the surgical positioning assembly  10  is actuated to disengage the spinal implant device  12  from the surgical positioning assembly  10  (Block  46 ). 
         [0023]    Although the present invention is illustrated and described herein with reference to preferred embodiments and specific examples thereof, it will be readily apparent to those of ordinary skill in the art that other embodiments and examples may perform similar functions and/or achieve like results. For example, the surgical positioning assembly of the present invention may be used to place any suitable implant device within any suitable implantation site, cage or non-cage/spinal or non-spinal, and the first and second axes along which access and placement are carried out may be those associated with any suitable surgical approach, provided that the second axis is disposed at an angle to, substantially perpendicular to, and/or simply rotated with respect to the first axis via the actuation of the surgical positioning assembly. All such equivalent embodiments and examples are within the spirit and scope of the present invention, are contemplated thereby, and are intended to be covered by the following claims.