US20070083200A1 - Spinal stabilization systems and methods - Google Patents

Abstract

Spinal stabilization devices, systems, and methods are described. In a first aspect, a foramenal spacer includes a rigid member adapted to maintain the integrity of the foramenal space. In a second aspect, facet joint stabilizing members and prosthetic facet joints are provided to augment or replace the native facet joint. In a third aspect, lateral spinal stabilization systems are adapted to be attached to the lateral surfaces of adjacent vertebral bodies. In a fourth aspect, anterior spinal stabilization systems are adapted to be attached to the anterior surfaces of adjacent vertebral bodies. In a fifth aspect, several embodiments of dynamic spinal stabilization devices and systems are described. Each of the foregoing devices, systems, and methods is suitable for use independently, in combination with other devices, systems, and methods described herein, and/or in combination with prosthetic intervertebral discs known in the art.

Description

BACKGROUND OF THE INVENTION
• The spine is comprised of twenty-four vertebrae that are stacked one upon the other to form the spinal column. The spine provides strength and support to allow the body to stand and to provide flexibility and motion. A Section of each vertebrae includes a passageway that provides passage of the spinal cord through the spinal column. The spine thereby encases and protects the spinal cord. The spinal cord also includes thirty-one pairs of nerve roots that branch from either side of the spinal cord, extending through spaces between the vertebrae known as the neural foramen.
• An intervertebral disc is located between each pair of-vertebrae. The disc is composed of three component structures: (1) the nucleus pulposus; (2) the annulus fibrosus; and (3) the vertebral endplates. The disc serves several purposes, including absorbing shock, relieving friction, and handling pressure exerted between the superior and inferior vertebral bodies associated with the disc. The disc also relieves stress between the vertebral bodies, which stress would otherwise lead to degeneration or fracture of the vertebral bodies.
• Disorders of the spine comprise some of the costliest and most debilitating health problems facing the populations of the United States and the rest of the world, costing billions of dollars each year. Moreover, as these populations continue to age, the incidence of spinal disorders will continue to grow. Typical disorders include those caused by disease, trauma, genetic disorders, or other causes.
• The state of the art includes a number of treatment options. Medicinal treatments, exercise, and physical therapy are typical conservative treatment options. Less conservative treatment options include surgical intervention, including microdiscectomy, kyphoplasty, laminectomy, dynamic stabilization, disc arthroplasty, and spinal fusion. Traditionally, these treatment options have been applied in isolation, rather than in combination, using the most conservative treatment option that will provide a desired result.
• U.S. Provisional Patent Application Ser. No. 60/713,671, entitled “Prosthetic Intervertebral Discs,” (“the '671 application”), was filed Sep. 1, 2005, and is assigned to Spinal Kinetics, Inc., the assignee of the present application. The '671 application describes, inter alia, a treatment option that combines a prosthetic intervertebral disc with a dynamic stabilization system. The '671 application is incorporated by reference herein in its entirety.
• In 1992, Panjabi introduced a model of a dynamic spinal stabilization system that describes the interaction between components providing stability in the spine. This model defined spinal instability in terms of a region of laxity around the neutral resting position of a spinal segment, identified as the “neutral zone.” Panjabi, M M., “The stabilizing system of the spine. Part II. Neutral zone and instability hypothesis.” J Spinal Disord 5 (4): 390-397, 1992b. There is some evidence that the neutral zone can be increased in cases of intervertebral disc degeneration, spinal injury and spinal fixation. Id Panjabi has subsequently described dynamic stabilization systems that provide increased mechanical support while the spine is in the neutral zone and decreased support as the spine moves away from the neutral zone. See United States Published Patent Application No. 2004/0236329, published Nov. 25, 2004, which is hereby incorporated by reference herein.
• The need remains for improved spinal stabilization systems, combinations of systems, and methods for their use.
SUMMARY OF THE INVENTION
• Spinal stabilization components, systems, and methods are provided. The spinal stabilization components are suitable for use individually, together, or with other known spinal stabilization components and systems.
• In a first aspect, foramenal spacers and methods for their use are described. The foramenal spacer includes a member that has a size and shape adapted for insertion into the foramen located between a pair of adjacent vertebral bodies to prevent the pair of vertebral bodies from collapsing into one another, i.e., to maintain the interpedicular spacing between the adjacent vertebral bodies. The foramenal spacer also preferably includes a passage or other member that protects the nerve root from being compressed or otherwise physically impacted as it traverses the foramen. In a first embodiment, the foramenal spacer includes an upper C-shaped member, a lower C-shaped member, and an attachment member for attaching the upper C-shaped member to the lower C-shaped member. The upper C-shaped member is adapted to be attached to the pedicle of the superior vertebral body and to extend into the foramen defined by the pair of vertebral bodies, while the lower C-shaped member is adapted to be attached to the pedicle of the inferior vertebral body and to extend into the foramen defined by the pair of vertebral bodies. When attached together, the upper and lower C-shaped members define a passageway therethrough for allowing passage of the nerve root. The attachment member may comprise a tongue and groove mechanism, a snap-fit mechanism, or other suitable mechanism for attaching the upper and lower C-shaped member together. Alternatively, the upper C-shaped member and lower C-shaped member may each be provided with surfaces adapted to butt up against one another to form a butt-joint. In still another embodiment, the C-shaped members are mated such that they allow some travel (e.g., extension) relative to each other, such as that which may be required during flexion, extension and lateral bending, and maintain the patentcy of the passageway to allow passage of the nerve root.
• In a second embodiment, the foramenal spacer includes an upper segment and a lower segment. The upper segment is adapted to be attached to the pedicle of the superior vertebral body and to extend into the foramen defined by the pair of vertebral bodies, and the lower segment is adapted to be attached to the pedicle of the inferior vertebral body and also to extend into the foramen defined by the pair of vertebral bodies. The interior surface of one of the upper segment or the lower segment and the external surface of the other of the upper segment or the lower segment define a pair of rounded, mating surfaces that together define a bearing structure that allows the upper segment to pivot relative to the lower segment. The upper segment and lower segment thereby act as a bearing to define a center of rotation. Once the upper segment and lower segment are attached to the respective vertebral bodies and are engaged with one another, the foramenal spacer provides a supporting structure that also protects the nerve root traversing the foramen, and that allows the superior and inferior vertebral bodies to pivot relative to one another.
• Preferably, the foramenal spacer is formed of a rigid biocompatible material, such as stainless steel, metal alloys, or other metallic materials, or a rigid polymeric material. In alternative embodiments, the foramenal spacer is provided with an outer layer formed of a soft, conformable material (e.g., an elastomeric polymer such as polyurethane) that provides conformability with the foramen geometry and allows flexion, extension and lateral bending of the spine. In still other embodiments, the foramenal spacer includes an inner liner formed of a soft and/or low-friction material to provide an atraumatic surface for passage of the nerve root.
• In a second aspect, devices, systems and methods for facet joint augmentation and replacement are provided. The devices and systems are intended to stabilize the spine and to increase the foramenal space to thereby reduce the likelihood of nerve root impingement. In a first embodiment, the stabilization and increase of foramenal space is accomplished by inserting a stabilizing member into the facet joint to restore the intra-foramenal distance. The stabilizing member comprises a structure that provides shock absorbance, cushioning, and support to the facet joint. In several embodiments, the stabilizing member comprises an encapsulated cushion. In other embodiments, the stabilizing member comprises a structure having a pair of endplates separated by a resilient core member.
• In a second embodiment, some or all of the facets of each of the superior and inferior vertebral bodies are removed and replaced with a facet joint implant. In several embodiments, the facet joint implant includes an upper prosthetic facet for attachment to the superior vertebral body, and a lower prosthetic facet for attachment to the inferior vertebral body. Each prosthetic facet is attached to its respective vertebral body by screws or other similar mechanisms. Each prosthetic facet joint includes a pair of facing plates and a core member located between the pair of facing plates. The prosthetic facet is constructed and attached in a manner such that it closely mimics the functionality and performance of the natural facet joint.
• In a third aspect, a lateral spinal stabilization device is provided. The lateral spinal stabilization device includes an upper attachment member and a lower attachment member for attaching to the lateral surfaces of each of the superior and inferior vertebral bodies, respectively, and a stabilizing member connected and extending between each of the upper and lower attachment members. In one embodiment, the stabilizing member comprises a damping mechanism. In other embodiments, the stabilizing member comprises a pair of endplates separated by a resilient core member.
• In a fourth aspect, an anterior spinal stabilization device is provided. The anterior spinal stabilization device is adapted to be attached to the anterior surfaces of a pair of vertebral bodies and to extend between the pair of vertebral bodies to provide stabilization to the anterior portion of the vertebral unit. In a first embodiment, the anterior spinal stabilization device is in the form of a spring having a structure sufficient to carry a load after implantation and attachment to the vertebral unit. The anterior stabilization device is preferably implanted by way of a minimally invasive anterior approach, although posterior and lateral approaches are also possible.
• In a fifth aspect, several dynamic stabilization devices are described. Each of the dynamic stabilization devices is intended to provide a combination of stabilizing forces to one or more spinal units to thereby assist in bearing and transferring loads. In a first embodiment, a dynamic stabilization device includes a posterior spacer member that is located generally between a pair of adjacent vertebral bodies on the posterior side of the spine. The posterior spacer is preferably formed of a generally compliant material and functions to maintain spacing between the pair of adjacent vertebral bodies while allowing relative motion between the vertebral bodies. In a preferred form, the posterior spacer is generally in the form of a short cylinder, having a central through-hole to allow passage of one or more restrictor bands, which are described more fully below. The spacer may take other shapes or forms, however, depending upon the size and shape of the spinal treatment site. The dynamic stabilization device also includes one or more restrictor bands, each of which preferably comprises a loop formed of an elastic material. The restrictor band(s) each have a size and shape adapted to be attached to the spinous processes extending from the posterior of the adjacent vertebral bodies, or to be attached by an appropriate attachment mechanism to the lamina of the adjacent bodies. Once linked to the posterior of the spine, the bands provide both stability and compliance. The performance properties of the bands are able to be varied by choice of materials, size of the bands, and by the routing of the restrictor band(s) between the adjacent vertebral bodies. For example, restrictor bands that are oriented more vertically than diagonally will provide greater resistance to flexion of the spine, whereas the more diagonal orientation will provide additional resistance to torsional movements.
• In other embodiments, a dynamic stabilization device is constructed and includes materials that allow the device to be adjusted post-operatively. For example, in one embodiment, the dynamic stabilization device includes a superior attachment member for attachment to the pedicle of a superior vertebral body, an inferior attachment member for attachment to the pedicle of an inferior vertebral body, and one or more spring members extending between and interconnecting the superior and inferior attachment members. In the preferred form, the spring member is formed of a shape memory material, such as nickel titanium alloy (Nitinol). The properties of the spring member may thereby be altered post-operatively by heating elements of the device, such as by applying an electric current. As the shape memory materials may be trained by heat treatment processes prior to implantation, the properties of the spring member may be altered in a known manner by application of heat in this manner. Preferably, the electric current is applied by placing leads against the spring member under X-ray or other guidance A given spring member may be extended or contracted to provide greater or lesser load support, or to alter any other performance characteristic of the device.
• In still other embodiments, a spinal stabilization device is provided that is capable of transferring reactions from one spinal segment to an adjacent segment. In this manner, the spinal stabilization device transfers loads and reactions in the same manner as is done by the natural spinal segments operating properly. The spinal stabilization device includes at least one fixation member associated with each vertebral body, and a linkage member extending between each pair of superior and inferior fixation members. The fixation members each allow for rotation of the linkage members, thereby providing the ability for one vertebral segment to be loaded (or unloaded), either in compression or torsion, based upon the activity being undergone at an adjacent vertebral segment.
• In still other embodiments, a dynamic stabilization device includes a combination of an interspinous stabilization member and one or more pedicle based stabilization members. In a preferred form, the one or more pedicle based stabilization members function by biasing the pair of adjacent vertebral bodies apart, while the interspinous stabilization member functions by biasing together the spinous processes of the adjacent pair of vertebral bodies. The combined action of the interspinous member and the pedicle based member(s) is to create a moment that relieves pressure from the disc.
• In still other embodiments, a dynamic stabilization device is provided and is attached to a pair of adjacent vertebral bodies at or near one or both pairs of transverse processes extending from the pair of vertebral bodies. For example, at least one superior attachment member, such as a screw, is attached to a transverse process of the superior vertebral body, at least one inferior attachment member, such as a screw, is attached to the transverse process of the inferior vertebral body, and a loading member extends between and interconnects the superior and inferior attachment members. The attachment members may optionally extend through the transverse processes into the vertebral bodies, or they may be attached to the vertebral bodies adjacent to the transverse processes.
• In still other embodiments, a dynamic stabilization device is attached such that the stabilization member is located externally of the patient's skin surface. In these embodiments, the stabilization member is attached to a pair of adjacent vertebral bodies by a pair of screws that extend through the patient's skin and into the pair of vertebral bodies. The stabilization member is then attached to and extends between the pair of screws on the exterior of the patient. The device is preferably fully adjustable.
• In yet other embodiments, a dynamic stabilization device is provided and includes a fill-type adjustment mechanism. The device includes a superior attachment member that is preferably attached to the spinous process of a superior vertebral body, an inferior attachment member that is preferably attached to the spinous process of an inferior vertebral body, and a stabilization member that extends between and interconnects the superior and inferior attachment members. The attachment members may include screws, or other suitable attachment mechanisms. Interposed between at least one of the attachment members and the stabilization member is a pot. As the pot is filled, such as by injecting a biocompatible material such as bone cement containing polymethylmethacrylate (PMMA), the added volume occupied in the pot decreases the operating length of the stabilization member, thereby also changing the performance characteristics of a given stabilization member. Thus, adding material to the pot provides the ability to adjust the device post-operatively. Preferably, the post-operative adjustment may be done percutaneously.
• In still other embodiments, a dynamic stabilization device includes an intervertebral spacer having an integrated stabilizing disc, the combined unit being interposed between the spinous processes of a pair of adjacent vertebral bodies.
• Each of the foregoing devices, structures, and methods is adapted to be used independently, or in combinations of two or more. Preferably, several devices, structures, or methods are used in combination to obtain desired results. In particular, each of the foregoing devices may be used in combination with a prosthetic intervertebral disc to obtain desired therapeutic results.
• Other and additional devices, apparatus, structures, and methods are described by reference to the drawings and detailed descriptions below.
BRIEF DESCRIPTION OF THE FIGURES
• The Figures contained herein are not necessarily drawn to scale, with some components and features being exaggerated for clarity.
• FIG. 1 is a lateral view of a pair of adjacent vertebral bodies, including representation of the foramen and nerve roots traversing the foramen.
• FIGS.2A-G are illustrations of foramenal spacers in accordance with the present invention.
• FIG. 3 is a posterior view of a pair of adjacent vertebral bodies, including representation of the facets and facet joints.
• FIG. 4 is a perspective view of an embodiment of a facet joint stabilizing member.
• FIG. 5 is a side view of another embodiment of a facet joint stabilizing member shown implanted in a facet joint.
• FIGS.6A-B are illustrations of prosthetic facets.
• FIG. 7 is an illustration of a portion of a spinal column having a plurality of prosthetic facets in place of the native facets.
• FIG. 8 is a lateral view of a pair of vertebral bodies having a lateral stabilization device implanted therebetween.
• FIG. 9A is a lateral view of a pair of vertebral bodies having an anterior stabilization device and a posterior stabilization device implanted therebetween.
• FIG. 9B is an illustration of an anterior stabilization device.
• FIG. 10A is an illustration of a spacer member.
• FIGS.10B-D are illustrations of posterior dynamic stabilization devices including a spacer member and restrictor bands.
• FIG. 11 is a posterior view of another dynamic stabilization system.
• FIG. 12 is a posterior view of another dynamic stabilization system.
• FIG. 13 is a lateral view of another dynamic stabilization system.
• FIG. 14 is a posterior view of another dynamic stabilization system.
• FIG. 15 is a lateral view of another dynamic stabilization system.
• FIG. 16 is a lateral view of another dynamic stabilization system.
• FIG. 17 is a lateral view of another dynamic stabilization system.
• FIG. 18 is a three dimensional cross-sectional view of an exemplary prosthetic intervertebral disc.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
• Before the present invention is described, it is to be understood that this invention is not limited to particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.
• Where a range of values is provided, it is understood that each intervening value, to at least the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges is also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention.
• Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited.
• It must be noted that as used herein and in the appended claims, the singular forms “a”, “an,” and “the” include plural referents unless the context clearly dictates otherwise.
• The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed.
• As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present inventions.
• Turning now to the drawings,FIG. 1 illustrates a pair of adjacent vertebral bodies, including a superiorvertebral body100 and an inferiorvertebral body102. Each vertebral body includes a pair of transverse processes104a-band aspinous process106 extending generally posteriorly from eachvertebral body100,102. Adisc108 is located between the superiorvertebral body100 and the inferiorvertebral body102. Thespinal cord110 extends through a central passage formed by the spinal column, andnerve roots112 transverse theforamenal space114 defined by the pair of vertebral bodies.
• When the disc is damaged due to trauma, disease, or other disorder, the superiorvertebral body100 and inferiorvertebral body102 tend to collapse upon each other, thereby decreasing the amount of space formed by theforamen114. This result also commonly occurs when the vertebral bodies are afflicted with disease or are fractured or otherwise damaged. When the foramenal space is decreased, thevertebral bodies100,102 tend to impinge upon thenerve root112, causing discomfort, pain, and possible damage to the nerve root. The foramenal spacers described herein are intended to alleviate this problem by maintaining the foramenal opening and otherwise protecting the nerve root from impingement by the vertebral bodies.
• Turning toFIGS. 2A through 2G, several foramenal spacer embodiments are shown. In a first embodiment, shown in FIGS.2A-D, theforamenal spacer120 includes a superior C-shapedmember122 and an inferior C-shapedmember124. The pair of C-shaped members preferably include an attachment mechanism or a pair of mating surfaces. For example, as shown inFIG. 2B, the superior C-shapedmember122 is provided with agroove126 on each of its inferior-facingsurfaces128, whereas the inferior C-shapedmember124 includes amating tab130 on each of its superior-facingsurfaces132. Alternatively, the tabs may be place on the superior C-shaped member and the grooves on the inferior C-shaped member, or still other attachment members may be used, such as a snap-fit mechanism or other similar structure. In still other embodiments, the mating surfaces128,132 may simply butt up against one another to form a butt-joint that prevents collapse of the foramenal space. When combined, the pair of C-shaped members define a generally disc-shapedmember134 having a central through-hole136. The central through-hole136 has a size and shape adapted to allow thenerve root112 to pass without impingement as shown, for example, inFIGS. 2C and 2D.
• Turning toFIG. 2E, theforamenal spacer120 may be provided with anouter layer140 that includes a coating of a soft, conformable material. Theouter layer140 preferably covers all of the external-facing surfaces of theforamenal spacer120, and particularly those that are positioned to engage the vertebral body surfaces. Theouter layer140 is preferably formed of a soft, conformable biocompatible material such as silicone, polyurethane, or other similar polymeric materials, and may be applied to theforamenal spacer120 by methods well-known in the art. Theouter layer140 may provide structural protection to the vertebral bodies forming the foramenal space, and also allows theforamenal spacer120 to adapt to the varying foramenal geometries formed by the vertebral bodies.
• An optional inner layer orliner142 may be provided on the exposed surfaces defining the through-hole136. The inner layer orliner142 is preferably formed of a coating of soft and/or low-friction material to provide an atraumatic surface for passage of thenerve root112. Preferably, the inner layer orliner142 is formed of similar materials as those used for theouter layer140, including silicone, polyurethane, or other polymeric materials. Alternatively, the inner layer orliner142 may comprise a coating of polyethylene, PTFE, or other similar material.
• In addition, an optional spring member, gasket, cushion, or other similar material or device (not shown in the drawings) may be interposed between the superior C-shapedmember122 and the inferior C-shapedmember124. Preferably, the spring member (or the like) may be located on the abutting surfaces of the two C-shaped members. This spring member (or the like) provides thespacer120 with the capability of vertical expansion and contraction as the spring member extends and compresses, thereby providing a range of motion for supporting the foramenal space.
• Turning now toFIG. 2F, another foramenal spacer embodiment is shown. In this embodiment, theforamenal spacer120 includes anupper segment150 and alower segment156. Theupper segment150 includes anexternal surface152 that has a shape adapted to engage the portion of the superior vertebral body defining theforamenal space114. Similarly, thelower segment156 includes anexternal surface158 that has a shape adapted to engage the portion of the inferior vertebral body defining theforamenal space114. Aninternal surface154 of theupper segment150 includes a curved portion that is adapted to rotatably engage a mating curved portion of theexternal surface158 of thelower segment156. In this way, theupper segment150 andlower segment156 are rotationally connected to one another, i.e. theupper segment150 andlower segment152 function similar to a bearing having a center of rotation. When theupper segment150 is attached to the superiorvertebral body100, and the lower segment is connected to the inferiorvertebral body102, theforamenal spacer120 allows the two vertebral bodies to pivot relative to one another, thereby providing an additional range of motion. Theforamenal spacer120 shown inFIG. 2F also optionally includes theouter layer140 and inner layer orliner142 described above in relation toFIG. 2E.
• Theforamenal spacer120 may be implanted by any appropriate surgical technique, including accessing the foramenal space by either a posterior approach or a lateral approach. The lateral approach is believed to provide optimal access to find exposure of the foramen, but techniques for posterior lumbar interbody fusion (PLIF) and transforamenal lumbar interbody fusion (TLIF) also provide sufficient access. Once access is gained, theforamenal spacer120 is preferably attached to the pedicle or other anatomic structure that allows extension of the spacer into theforamenal space114. For example, theforamenal spacer120 may be press fit into theforamen116, as illustrated inFIG. 2G, or a tab (not shown) may be provided for attaching theforamenal spacer120 to the pedicle or other anatomical structure.
• Turning next toFIG. 3, a posterior view of a pair of adjacent vertebral bodies is shown. The Figures illustrates a superiorvertebral body100 and an inferiorvertebral body102. Each vertebral body includes a pair of transverse processes104a-band aspinous process106 extending generally posteriorly from eachvertebral body100,102. Thespinal cord110 extends through a central passage formed by the spinal column, andnerve roots112 transverse theforamenal space114 defined by the pair of vertebral bodies. A facet joint118 is formed by a pair of facing facets, one each from the superior and inferior vertebral bodies.
• Several of the known devices and systems for posterior spinal stabilization are designed and provide the function of opening the foramen or maintaining the foramenal spacing in order to off-load the nerve that traverses the foramen. This is commonly done by attaching a device to the pedicles of each of the vertebral bodies and providing a distracting force between the attachment members. Several alternative and novel devices and methods are described herein.
• Turning toFIG. 4, afacet stabilizing member170 is shown. Thefacet stabilizing member170 preferably includes acore member172 encased in ajacket174. Thecore member172 is preferably formed of a hydrogel, polyurethane, or other polymeric material suitable for providing the shock absorbing and spacing function necessary to stabilize the facet joint. Thejacket174 may be a woven fabric of biocompatible material and is intended to maintain the integrity and shape of thecore member172 and to otherwise provide structural strength to thefacet stabilizing member170. Thefacet stabilizing member170 has a size and shape adapted to be placed in the facet joint118 to thereby provide stabilization to the joint and to prevent collapse of the foramenal space.
• Turning toFIG. 5, another embodiment of afacet stabilizing member170 is shown. In this embodiment, the spinal stabilizingmember170 includes anupper endplate180, alower endplate182, and acore member184 extending between and interconnecting theupper endplate180 andlower endplate182. Preferably, the facet stabilizing member also includes a plurality offibers186 wound between and interconnecting theupper endplate180 andlower endplate182. The construction and materials of thefacet stabilizing member170 shown inFIG. 5 are similar to the construction and materials of the prosthetic intervertebral disc described below in relation toFIG. 18, and to several of the prosthetic intervertebral discs described in U.S. Patent application Ser. No. 10/903,276, filed Jul. 30, 2004, and U.S. Patent Application Ser. No. 60/713,671, filed Sep. 1, 2005, each of which applications is hereby incorporated by reference herein. Other prosthetic discs described in the foregoing applications may also be adapted for use as afacet stabilizing member170 as described herein. The size of thefacet stabilizing member170 is typically smaller than the sizes of the prosthetic discs described in the foregoing applications, but the overall construction of the structure is preferably the same.
• Thefacet stabilizing member170 is implanted between the pair of opposed facets associated with the pair of adjacent vertebral bodies. Additional features, such as fins, fixation members, or other structures (not shown), may also be incorporated on thefacet stabilizing member170 to limit translation. The facet joint is synovial, therefore requiring implantation through the capsule. Access to the facet joint is obtained by any of the methods described above in relation to implantation of the foramenal space r.
• Turning to FIGS.6A-B, prosthetic facets and facet joints are shown. During many spinal surgical procedures, particularly those including approach by the posterior, some or all of the facet is removed to provide access to implant one or more prosthetic structures. Similarly, many spinal procedures create loss of height of the disc or similar unintended results. In these cases, or in cases in which the facets or facet joints become damaged through trauma, disease, or other disorder, it may be desirable to replace some or all of the facet with a prosthetic device to restore stabilization to the affected spinal segments.
• InFIG. 6A, a number ofprosthetic facets190 are shown as implanted in several locations on a spinal column. Eachprosthetic facet190 includes anattachment arm192 that is generally elongated and curved to match the shape and structure of the native facet. Theattachment arm192 terminates in anendplate194 that mimics the facing surface of the native facet. Theattachment arm192 is attached to its associated vertebral body by one ormore screws196 or other suitable attachment mechanism. Afacet stabilizing member170, identical to those described above in relation toFIG. 5, is interposed between a pair ofprosthetic facets190, with thefacet endplates194 serving as the endplates for thefacet stabilizing member170. (See, in particular,FIG. 6B). As shown inFIG. 6A, the prosthetic facet joint is oriented to be on plane with the native facet. Thus, the orientation of the facet joint will vary between vertebral segments.
• FIG. 7 illustrates a multi-level stabilization over several adjacent vertebral segments using theprosthetic facets190. A firstprosthetic facet190 is attached to the sacrum119, and additionalprosthetic facets190 are attached to the L5 and L4 vertebrae.
• Turning next toFIG. 8, a lateral stabilization device is shown. Thelateral stabilization device200 includes an upper attachment arm202aadapted to be attached to the superiorvertebral body100 by one ormore screws204 or other attachment mechanism, and alower attachment arm202badapted to be attached to the inferiorvertebral body102 by one ormore screws204 or other attachment mechanism. The device also includes astabilization member206. Thestabilization member206 may include a spring, a combination of springs, a damping mechanism, or other mechanism that provides a desired stabilization function. In a preferred embodiment, the stabilization member includes a structure identical to thefacet stabilization member170 described above in relation toFIG. 5.
• Advantageously, thelateral stabilization device200 is attached to the lateral surfaces of the pair of adjacentvertebral bodies100,102. In a particularly preferred embodiment, alateral stabilization device200 is attached on both lateral sides of the pair of vertebral bodies.
• FIG. 9 shows a pair of adjacentvertebral bodies100,102 having both aposterior stabilization device210 and ananterior stabilization device220 attached to each of the pair of vertebral bodies. Theposterior stabilization device210 includes a pair of pedicle screws212, one attached to each of the superiorvertebral body100 and the inferiorvertebral body102. Astabilization member212 extends between and interconnects the pair of pedicle screws212. Thestabilization member214 may comprise a load bearing dynamic structure that is spring loaded, that includes a damping member, or any combination of such structures. Theanterior stabilization device220 includes ananterior element222, the details of which are best shown inFIG. 9B. Theanterior element222 is preferably formed of a material having superelastic properties, and includes a shape that allows theanterior element222 to be constrained for a minimally invasive implantation procedure. As shown, theanterior element222 includes anattachment hole224 at each end, and acentral portion226 that includes a pair ofside bands228a-bthat define acentral aperture230. Theanterior element222 may be rolled or compressed into a low profile contracted state for implantation. Once introduced, the anterior element is partially released from the contracted state and attached to the pair of vertebral bodies adjacent to the damageddisc108. Theanterior element222 is preferably attached by screws or other suitable mechanisms. Once attached, theanterior element222 is fully extended to its operative state and is capable of bearing loads to provide stabilization to the vertebral segments.
• Theanterior stabilization device220 may be used alone, in combination with theposterior stabilization device210 illustrated inFIG. 9A, or in combination with any other suitable stabilization device or structure. By using a combination of stabilization devices, it may be possible to provide additional amounts or types of stabilization and unloading of the vertebral segment than is possible by use of only a single stabilization structure.
• Turning now to FIGS.10A-D, several embodiments of a posterior dynamic stabilization device are shown. The dynamic stabilization devices include a posterior spacer and one or more restrictor bands. As explained below, the spacer may be integrated with the restrictor band(s), or it may be provided independently of the restrictor band(s).
• Turning first toFIG. 10A, aposterior spacer240 is shown. Theposterior spacer240 is generally in the shape of a short cylinder, having a central through-hole242 and anupper surface244 andlower surface246. Theposterior spacer240 may optionally be provided in any other form or shape, as described more fully below. Thespacer240 is preferably formed of a generally compliant biocompatible material, such as a polyurethane, silicone, or other suitable polymeric material. As shown in FIGS.10B-D, thespacer240 is generally located between the spinous processes of a pair of adjacent vertebral bodies. The spacer maintains the spacing between the vertebral bodies while allowing a desired amount of relative motion between the two vertebral bodies.
• The restrictor band(s)250 are each preferably formed in a continuous loop and are formed of a relatively elastic biocompatible material, such as any number of elastomeric and/or polymeric materials suitable for the purpose. The restrictor band(s)250 are linked to the posterior spine to provide both stability and compliance. The band(s)250 are attached either to the lamina by way of attachment screws252 or other suitable attachment mechanisms (seeFIG. 10C, or they are looped directly onto thespinous processes106 of the pair of vertebral bodies (seeFIGS. 10B, 10D). The materials, sizes, structures, and routing of the restrictor band(s)250 are able to be tailored to obtain a desired type and degree of constraint. For example, a routing pattern that is oriented relatively more diagonally, as inFIG. 10C, will provide more resistance to torsional movement than will a routing pattern that is oriented more vertically, as inFIG. 10D. Other routing variations are also possible, as will be recognized by those skilled in the art.
• Turning now toFIG. 11, another embodiment of a dynamic spinal stabilization device is shown. The device includes a construction and that provides the capability of adjusting the performance characteristics of the stabilization device after it has been implanted. In the illustrated embodiment, thespinal stabilization device260 includes asuperior attachment member262 and aninferior attachment member264, for attachment to a superiorvertebral body100 and an inferiorvertebral body100, respectively. Thesuperior attachment member262 andinferior attachment member264 may be attached to thespinous processes106 of the respectivevertebral bodies100,102, as shown, or they may be attached to the pedicles or other suitable portions of the vertebral bodies. Theattachment members262,264 preferably comprise screws, although other attachment members may be used as desired or as suitable. Thestabilization device260 includes one ormore spring elements266 that each extend between and interconnect thesuperior attachment member262 andinferior attachment member264. Eachspring element266 is preferably formed of nickel titanium alloy (Nitinol) or other suitable biocompatible shape memory material. The shape and properties of eachspring element266 are able to be altered at any time, either prior to implantation or after implantation, by heating the spring element, for example, using an electric current. The shape memory material may be trained by a heating process to conform to a predetermined shape upon being heated to a predetermined temperature, in a manner known to those skilled in the art. Thus, the user is able to alter the shape, size, or performance characteristics of thespring elements266 through application of heat to those members. For example, leads may be placed in contact with thespring elements266 under X-ray or other guidance after implantation in the spine of a patient. Electric current is then supplied to thespring elements266 through the leads, allowing the user to alter the size, shape, or performance characteristics of the spring elements.
• Although thespring elements266 shown in the embodiment illustrated inFIG. 11 are generally straight struts, thespring elements266 may alternatively be provided in any shape, size, or orientation suitable for a given application.
• Turning next toFIG. 12, another spinal stabilization device is shown in a generally schematic representation. The spinal stabilization device illustrated inFIG. 12 is adapted to transfer loads from one motion segment to adjacent segments. Three adjacentvertebral bodies270,272, and274 are shown schematically in the Figure. A pair ofinterconnected stabilization devices276 are attached to each of the three vertebral bodies. Eachstabilization device276 includes afixation element278 attached to each vertebral body and alinkage280 extending between and attached to each adjacent pairo fixation elements278.
• Each of thefixation elements278 comprises a bearing structure or similar mechanism that provides the capability of rotating the attachedlinkage280. This allows a first vertebral segment, such asvertebral body270, to be loaded in reaction to a load placed upon the adjacent vertebral segments, such asvertebral bodies272 and274: As a non-limiting example, when the lowestvertebral body274 moves to the right, as shown by arrow “A”, the transfer of this load through rotation of thefixation elements278 imposing loading upon the attachedlinkages280 influences the uppervertebral body270 to move to the left, as shown by arrow “B”. This movement is consistent with the natural movement of the spine when the body twists. Compression and flexion loads are transferred in a similar manner.
• As noted above, each of thefixation elements278 is preferably in the form of a bearing or similar rotatable structure that provides rotational movement as represented by the arrows “C”. Thelinkages280 may comprise a spring element or multiple spring elements having a size, shape, spring constant, and other characteristics that provide the desired amount of load transfer in response to rotation of thefixation elements278. In addition, although twostabilization devices276 are shown in the Figure, more or fewer devices may be used depending upon the degree of stabilization needed or desired. Thestabilization devices276 may also extend between more (e.g., four or more) or fewer (e.g., two) adjacent vertebral segments.
• Turning next toFIG. 13, a multi-component dynamic stabilization system is shown schematically. Current dynamic spinal stabilization systems are typically either interspinous devices (i.e., connected between the spinous processes of adjacent vertebral bodies) or pedicle screw based devices (i.e., connected between pedicle screws attached to the pedicles of adjacent vertebral bodies). Each of these types of dynamic stabilization devices functions by providing a distracting force that unloads thedisc108. The system shown inFIG. 13 includes aninterspinous stabilization system290 connected to thespinous processes106 of a pair of adjacentvertebral bodies100,102, and a pair of pedicle basedstabilization systems292a-b(only one of the pedicle based systems is shown in the Figure) attached by pedicle screws to the pair of adjacentvertebral bodies100,102 on each side of the spinous processes. Each of the pedicle basedsystems292a-bcomprises a spring loaded or other suitable structure that provides a distracting force, represented by arrows “D”, that tends to unload thedisc108. Theinterspinous system290, on the other hand, includes a spring loaded or other suitable structure that biases thespinous processes106 of the adjacentvertebral bodies100,102 toward one another, as represented by arrows “E”. The combined action of theinterspinous system290 and the pedicle basedsystems292a-bcreates a moment that relives pressure from thedisc108.
• Advantageously, theinterspinous system290 and/or the pedicle basedsystems292a-bof the foregoing embodiment may be constructed such that one or more of the systems is externally adjustable, as described, for example, in relation the devices illustrated inFIG. 11.
• Turning next toFIG. 14, a pair of adjacentvertebral bodies100,102 are shown. Adynamic stabilization device300 is attached to each of the vertebral bodies at a position at or near the transverse processes104a-bof eachvertebral body100,102. Eachdynamic stabilization device300 includes anupper attachment screw302 and alower attachment screw304. Thescrews302,304 may be placed through the transverse process to the vertebral body, or they may be attached direction to the vertebral body adjacent the transverse process104a-b. Aloading member306 is attached to each of theupper attachment screw302 and thelower attachment screw304 and extends therebetween. Theloading member306 is adapted to stabilize the adjacent vertebral bodies by providing an appropriate level of distraction or attraction forces. Theloading member306 may comprises a spring, a set of springs, a damping member, or any other suitable structure such as those described elsewhere herein.
• FIG. 15 provides a schematic illustration of an externally adjustable dynamic stabilization system. The system includes anupper screw310 andlower screw312 extending posteriorly from a superiorvertebral body100 and an inferiorvertebral body102, respectively. Each screw extends outside of the patient's body. Astabilization member314 is attached to each of thescrews310,312 on the external surface of the patient's back, i.e., outside the surface of theskin316. Thestabilization member316 may be a spring loaded, multiple spring loaded, damping mechanism, or any other suitable stabilization system such as those described elsewhere herein. Advantageously, thestabilization system316 is readily adjustable post-operatively because it is located externally of the patient. Accordingly, any adjustments to the performance of the system may be made easily and without the need for additional surgical intervention.
• FIG. 16 is a schematic illustration of another adjustable stabilization system. Thespinal stabilization system320 includes anupper pot322 attached to thespinous process106 of a superiorvertebral body100, and alower pot324 attached to thespinous process106 of an inferiorvertebral body102. Each of theupper pot322 andlower pot324 forms a portion of the attachment mechanism for the stabilization device. Theupper pot322 andlower pot324 may be attached to thespinous processes106 by any suitable mechanism, such as one or more screws. Each of theupper pot322 andlower pot324 includes a cylindrical portion that is adapted to receive aconnector326 located at each of the upper end and lower end of aspring328. Each of theconnectors326 engages one of theupper pot322 andlower pot324, thereby allowing thespring328 to provide a distracting force to thevertebral bodies100,102.
• Because theupper pot322 andlower pot324 are generally hollow, it is possible to partially fill one or both of thepots322,324 to decrease the effective length of thespring328 extending between the pots, i.e., partially filling the pots causes the connectors to engage the filler material at a level removed from the bottom of thepot322,324. Either or both of thepots322,324 may be partially filled with bone cement containing polymethylmethacrylate (PMMA) or another suitable material. Preferably, the filling operation may be performed post-operatively by way of a percutaneous access, thereby eliminating the need for additional surgical intervention.
• FIG. 17 provides an illustration of another dynamic stabilization system. Thestabilization system340 includes a DIAM™ typeintervertebral spacer342 interposed between thespinous processes106 of a pair of adjacentvertebral bodies100,102. DIAM™ type intervertebral spacers are commercially available and are produced by Medtronic Sofamor Danek. Thespacer342 is generally “H” shaped, including a relatively narrow center section located between relatively wider side sections. This shape allows the spacer to be effectively sandwiched between thespinous processes106 of a pair of adjacentvertebral bodies100,102, as shown inFIG. 17. Thespacer342 is a silicone device covered with polyethylene, and functions by reducing loading of the disc, restoring the posterior tension band, realigning the facets, and restoring the foramenal height.
• In addition, a stabilizing disc344 is interposed between thespinous processes106 in place of a portion of thespacer340. The stabilizing disc344 has a structure and is constructed in a manner identical to thefacet stabilizing member170 described above in relation toFIG. 5, having a core member located between a pair of endplates. The stabilizing disc344 allows for compression. and rotation, if needed. The stabilizing disc344 also facilitates lateral bending.
• As noted above, this application incorporates by reference U.S. Provisional Patent Application Ser. No. 60/713,671, entitled “Prosthetic Intervertebral Discs,” (“the '671 application”), which was filed Sep. 1, 2005, and which is assigned to Spinal Kinetics, Inc., the assignee of the present application. The '671 application describes, inter alia, spinal treatment methods that combine a prosthetic intervertebral disc with a dynamic stabilization system. Each of the dynamic stabilization systems described in the present application are suitable for use in combination with prosthetic intervertebral discs such as those described in the '671 application, and others described in U.S. patent application Ser. No. 10/903,276, filed Jul. 30, 2004, (“the '276 application”), which is also incorporated by reference herein.
• For example, an exemplary prostheticintervertebral disc1100 is shown inFIG. 18, which is reproduced from FIG. 3 of the '671 application and which was also described in the '276 application. This prosthetic disc is described for exemplary purposes, and is not intended to represent the only type of prosthetic disc that is suitable for use in combination with the devices and systems described elsewhere herein. Turning to the Figure, theprosthetic disc1100 has an integrated structure that includes anupper endplate1110, alower endplate1120, and acore member1130 retained between theupper endplate1110 and thelower endplate1120. One ormore fibers1140 are wound around the upper and lower endplates to attach the endplates to one another. The wind of thefibers1140 allows a degree of axial rotation, bending, flexion, and extension by and between the endplates. Anannular capsule1150 is optionally provided in the space between the upper and lower endplates, surrounding thecore member1130 and thefibers1140. Theupper endplate1110 andlower endplate1120 are generally flat, planar members, and are fabricated from a biocompatible material that provides substantial rigidity.
• The upper surface of theupper endplate1110 and the lower surface of thelower endplate1120 are preferably each provided with a mechanism for securing the endplate to the respective opposed surfaces of the upper and lower vertebral bodies between which the prosthetic disc is to be installed. For example, inFIG. 18, theupper endplate1110 includes a plurality of anchoring fins1111a-b. The anchoring fins1111a-bare intended to engage mating grooves that are formed on the surfaces of the upper and lower vertebral bodies to thereby secure the endplate to its respective vertebral body. The anchoring fins1111a-bextend generally perpendicularly from the generally planar external surface of theupper endplate1110, i.e., upward from the upper side of the endplate as shown inFIG. 18. Each of the anchoring fins1111a-bhas a plurality ofserrations1112 located on the top edge of the anchoring fin. Theserrations1112 are intended to enhance the ability of the anchoring fin to engage the vertebral body and to thereby secure theupper endplate1110 to the spine.
• Similarly, the lower surface of thelower endplate1120 includes a plurality of anchoring fins1121a-b. The anchoring fins1121a-bon the lower surface of thelower endplate1120 are identical in structure and function to the anchoring fins1111a-bon the upper surface of theupper endplate1110, with the exception of their location on the prosthetic disc.
• The anchoring fins1111,1121 may optionally be provided with one or more holes orslots1115,1125. The holes or slots help to promote bony ingrowth that assist in anchoring theprosthetic disc1100 to the vertebral bodies.
• Theupper endplate1110 contains a plurality ofslots1114 through which thefibers1140 may be passed through or wound, as shown. The actual number ofslots1114 contained on the endplate is variable. The purpose of thefibers1140 is to hold theupper endplate1110 andlower endplate1120 together and to limit the range-of-motion to mimic the range-of-motion and torsional and flexural resistance of a natural disc.
• Thecore member1130 is intended to provide support to and to maintain the relative spacing between theupper endplate1110 andlower endplate1120. Thecore member1130 is made of a relatively compliant material, for example, polyurethane or silicone, and is typically fabricated by injection molding. A preferred construction for the core member includes a nucleus formed of a hydrogel and an elastomer reinforced fiber annulus. The shape of thecore member1130 is typically generally cylindrical or bean-shaped, although the shape (as well as the materials making up the core member and the core member size) may be varied to obtain desired physical or performance properties. For example, thecore member1130 shape, size, and materials will directly affect the degree of flexion, extension, lateral bending, and axial rotation of the prosthetic disc.
• Theannular capsule1150 is preferably made of polyurethane or silicone and may be fabricated by injection molding, two-part component mixing, or dipping the endplate-core-fiber assembly into a polymer solution. A function of the annular capsule is to act as a barrier that keeps the disc materials (e.g., fiber strands) within the body of the disc, and that keeps natural in-growth outside the disc.
• The foregoingprosthetic disc1100, or other suitable prosthetic discs, may be implanted by surgical techniques described in the '671 and '276 applications and elsewhere. As described above, it will often be advantageous to combine the prosthetic intervertebral disc with any of the other devices, systems, and methods described herein to obtain synergistic therapeutic results in treatment of spinal disease, trauma, or other disorder.
• Accordingly, it is to be understood that the inventions that are the subject of this patent application are not limited to the particular embodiments described, as such may, of course, vary. In particular, it is specifically contemplated that two or more of the specific embodiments described herein may be combined, to the extent that the embodiments are compatible with one another. Such combinations provide performance benefits that exceed those available to known devices or devices utilized independently.
• Unless defined otherwise, all technical arid scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which these inventions belong. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present inventions, the preferred methods and materials are herein described.
• All patents, patent applications, and other publications mentioned herein are hereby incorporated herein by reference in their entireties. The patents, applications, and publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed.
• As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present inventions.
• The preceding merely illustrates the principles of the invention. It will be appreciated that those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the invention and are included within its spirit and scope. Furthermore, all examples and conditional language recited herein are principally intended to aid the reader in understanding the principles of the invention and the concepts contributed by the inventors to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the invention as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents and equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure. The scope of the present invention, therefore, is not intended to be limited to the exemplary embodiments shown and described herein. Rather, the scope and spirit of present invention is embodied by the appended claims.

Claims (17)

1. A foramenal spacer, comprising:

a first support member having an external surface configured to engage the pedicle surface of a first vertebral body of a patient;

a second support member having an external surface configured to engage the pedicle surface of a second vertebral body of a patient, said second vertebral body being adjacent to said first vertebral body;

said first support member and said second member being connected together such that a foramenal height between said first vertebral body and said second vertebral body is maintained at no less than a minimum foramenal height when said foramenal spacer is interposed between said first vertebral body and second vertebral body.

2. The foramenal spacer ofclaim 1, wherein said first support member and said second support member define a passage therebetween.

3. The foramenal spacer ofclaim 2, wherein said first support member and said second support member are capable of rotational movement relative to one another.

4. The foramenal spacer ofclaim 2, wherein said first support member and said second support member are capable of expansive movement relative to one another.

5. A method for augmenting a facet joint between a superior vertebral body and an inferior vertebral body of a patient, comprising:

providing a facet stabilizer, said facet stabilizer including a first endplate, a second endplate, and a core member interposed between said first endplate and said second endplate; and

implanting said facet stabilizer between the facets comprising said facet joint.

6. A method for mammalian spinal stabilization, comprising:

implanting a prosthetic intervertebral disc between a superior vertebral body and an inferior vertebral body of a patient; and

implanting a stabilizer system configured to engage said superior vertebral body and said inferior vertebral body of said patient.

7. The method ofclaim 6, wherein said stabilizer system comprises a spacer interposed between the spinous processes of each of said superior vertebral body and said inferior vertebral body.

8. The method ofclaim 7, wherein said stabilizer system further comprises a restrictor band attached to each of said superior vertebral body and said inferior vertebral body.

9. The method ofclaim 7, wherein said stabilizer system further comprises a disc member embedded in said spacer, said disc member comprising an upper endplate, a lower endplate, and a core member located between said upper endplate and said lower endplate.

10. The method ofclaim 6, wherein said stabilizer system comprises a first attachment member connected to said superior vertebral body, a second attachment member connected to said inferior vertebral body, and a stabilizer member connected to each of said first attachment member and said second attachment member.

11. The method ofclaim 10, wherein said stabilizer member comprises a shape memory material.

12. The method ofclaim 10, wherein at least one of said first attachment member and said second attachment member is rotatable, and wherein rotation of at least one of said first attachment member and said second attachment member causes force from movement of one of said superior vertebral body or said inferior vertebral body to be transferred to said other of said superior vertebral body or said inferior vertebral body.

13. The method ofclaim 6, wherein said stabilizer system comprises a first member attached to and configured to impart a distracting force between each of said superior vertebral body and said inferior vertebral body, and a second member attached to and configured to impart an attracting force between each of said superior vertebral body and said inferior vertebral body.

14. The method ofclaim 10, wherein said first attachment member is connected to a transverse process of said superior vertebral body, and said second attachment member is connected to a transverse process of said inferior vertebral body.

15. The method ofclaim 10, wherein said stabilizer system further comprises a pot configured to receive and retain a filler material.

16. The method ofclaim 6, wherein said stabilizer system is attached to lateral surfaces of said superior vertebral body and said inferior vertebral body.

17. The method ofclaim 6, wherein said stabilizer system is attached to anterior surfaces of said superior vertebral body and said inferior vertebral body.

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