DEVICES AND METHODS FOR INTER-VERTEBRAL ORTHOPEDIC DEVICE PLACEMENT
Disclosed are devices and methods for the placement of a bone fusion implant between vertebral bodies in a human or animal subject. In an exemplary method a pathway is formed in the first sacral vertebrae along a trajectory that has a starting point between the inferior aspect of the facet joint and the first posterior sacral foramen and transverses at least one pedicle, at least a portion of the first sacral vertebra and the disc space immediately superior to the sacrum. A fusion implant is placed into the formed pathway. Additional bone fasteners and inter-connecting rods are added to the fusion implant in order to further strengthen the construct. Embodiments that can be used to fuse an additional level are also disclosed.
This application is a continuation of co-pending U.S. application Ser. No. 11/543,012, entitled “Devices and Methods for Inter-vertebral Orthopedic Device Placement,” filed Oct. 3, 2006, which claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 60/723,185, entitled “Device for the Stabilization of the Low Lumbar Spine and Method of Use” by M. Samy Abdou, filed Oct. 3, 2005, and U.S. Provisional Patent Application Ser. No. 60/809,199, filed May 30, 2006. Priority of the aforementioned filing dates is hereby claimed and the disclosures of the Applications are hereby incorporated by reference in their entirety.
This application also is related to International application Serial No. PCT/US2006/38865, filed the same day herewith.
Where permitted, the subject matter of each of the above noted provisional applications, and international application is incorporated by reference in its entirety by reference thereto.
BACKGROUNDThe present disclosure relates to methods and devices that permit stabilization of the bony elements of the skeleton. The devices permit adjustment and maintenance of the spatial relationship(s) between neighboring bones. Depending on the specifics of the design, the motion between skeletal segments can be immobilized completely or preserved.
Surgical reconstructions of the bony skeleton are common procedures in current medical practice. Regardless of the anatomical region or the specifics of the reconstructive procedure, many surgeons employ an implantable device that can adjust, align and maintain the spatial relationship(s) between adjacent bones.
Whether from degenerative disease, traumatic disruption, infection or neoplastic invasion, alteration in the anatomical relationships between the spinal vertebrae can cause significant pain, deformity and disability. Spinal disease is a major health problem in the industrialized world and the surgical treatment of spinal pathology is an evolving discipline. The current surgical treatment of abnormal vertebral motion is the complete immobilization and bony fusion of the involved spinal segment. An extensive array of surgical techniques and implantable devices has been formulated to accomplish this goal. More recently, alternative techniques have been developed to correct the abnormal vertebral motion and preserve spinal mobility.
Symptomatic degeneration of the lumbar spine occurs most commonly at the L4/L5 and L5/S1 levels. Fusion of one or both of these segments has emerged as a common surgical procedure. Currently, these vertebral bodies can be fused using an anterior, lateral or posterior approach and each has particular advantages and draw backs. Frequently, circumferential fusion of the unstable level with fixation of both the anterior and posterior aspect of the spine is desired. This requires that patients undergo a combination of the aforementioned approaches. The anterior or lateral approaches are used to insert the bone graft into the disc space between the adjacent vertebrae while the posterior approach is used to place bone screws or similar fasteners that are used to immobilize the vertebral bodies.
Currently, circumferential fusion requires a combination of approaches and multiple surgical incisions. A minimally invasive procedure that can provide circumferential access to the lower lumbar spine is clearly needed.
SUMMARYDisclosed are devices and methods for providing circumferential lumbar fusion through a single approach. The method of use minimizes the dissection of normal tissues and avoids retraction and manipulation of the nerve elements. The method also provides ease of use as well as a safe and familiar surgical approach that maximizes the likelihood of optimal graft placement within the inter-vertebral disc space. The device can be placed through a posterior approach to the spine and thus avoids the risk of an intra-abdominal operation.
In one aspect, a bone screw is placed through the pedicle portion of the vertebral body immediately superior to the sacrum. This is usually, but not always, the L5 vertebral body. For simplicity, it will be assumed to be the L5 vertebral body and will be so designated for the remainder of the application. A curvilinear bone graft containment cage is advanced through the posterior portion of the sacrum, the sacral pedicle, the disc space immediately above the sacrum (designated the L5/S1 disc space) and onto or into the inferior aspect of the L5 vertebral body. A rod or similar connecting member is used to connect the L5 screw with the posterior aspect of the bone cage and/or sacral screw. The procedure can be performed unilaterally or, more preferably, bilaterally. Alternatively, the procedure can be used unilaterally in conjunction with additional methods of vertebral fixation. The latter include but are not limited to use of a facet-locking screw to fixate the contra-lateral facet joint or a device to fixate the spinous processes.
In additional embodiments, a shorter L5 bone screw is used and the cage is driven through the L5 vertebral body and L4/5 disc space and onto or into the inferior aspect of the L4 vertebral body. A rod or other connecting element is used to connect the L4 and L5 bone screws to the cage and/or onto an S1 bone screw. In this way, circumferential fixation of L4 to S1 is achieved. As before, the procedure can be performed unilaterally, bilaterally or in combination with other fixation techniques.
In other embodiments, the curvilinear device and/or approach through the sacrum is used to place a tissue graft, biological extracts or agents, nucleus replacement prosthesis or any desired material into the L5/S1 and/or L4/5 disc spaces. In a final embodiment, devices and methods are used to distract neighboring vertebral bodies.
The devices disclosed herein and the methods of placement provide an easy and reliable way for circumferential stabilization of the lower lumbar spine through a single approach. Depending on the use of the prosthesis, the disclosed device can be used to fuse the targeted vertebral bodies or as conduit for the placement of biologic or synthetic substances into the disc space(s). The disclosed method of implant use is safe; it employs a posterior approach that is familiar to all spine surgeons and the method minimizes the extent of dissection of the normal tissues.
A bone fusion implant is disclosed in which the implant is adapted to be positioned between vertebral bodies in a human or animal subject. In one embodiment, the bone fusion implant includes an elongate member. The elongate member is sized and shaped to be positioned within a pathway in the first sacral vertebra along a trajectory that has a starting point between a portion of the facet joint and the posterior sacral foramen, that transverses at least one sacral pedicle and at least a portion of the first sacral vertebral body and that enters the disc space immediately superior to the sacrum. In another embodiment, the implant includes a curvilinear member sized and shaped to be positioned within a curvilinear pathway that joins at least two vertebral bodies and at least partially contains a bone graft.
A method is disclosed for the placement of a bone fusion implant between vertebral bodies in a human or animal subject. The method includes placing an implant into a pathway formed in a first sacral vertebra along a trajectory that has a starting point between a portion of the facet joint and the posterior sacral foramen, transverses at least one sacral pedicle and at least a portion of the first sacral vertebral body and enters the disc space immediately superior to the sacrum.
A method is disclosed for the placement of a tissue graft, biological extracts or agents, nucleus replacement prosthesis or any desired material into disc space between vertebral bodies in a human or animal subject is disclosed. The method includes placing the material into the disc space through a pathway formed in the first sacral vertebra along a trajectory that has a starting point between a portion of the facet joint and the posterior sacral foramen, transverses at least one sacral pedicle and at least a portion of the first sacral vertebral body and enters the disc space immediately superior to the sacrum.
A method for vertebral movement in a human or animal subject is disclosed. The method includes forming a pathway in the first sacral vertebra along a trajectory that has a starting point between a portion of the facet joint and the posterior sacral foramen, transverses at least one sacral pedicle and at least a portion of the first sacral vertebral body and enters the disc space immediately superior to the sacrum; placing a first distraction member with a central opening through the pathway and into contact with a lower vertebral body to be moved; placing a second distraction member through the central opening of the first distraction member and into contact with an upper vertebral body to be moved; and applying a force so as to move and displace the first and second distraction members and the attached upper and lower vertebral bodies relative to one another.
Another method for vertebral movement in a human or animal subject is disclosed. The method includes forming a pathway in a first sacral vertebra along a trajectory that has a starting point between a portion of a facet joint and the posterior sacral foramen, transverses at least one sacral pedicle and at least a portion of the first sacral vertebral body and enters the disc space immediately superior to the sacrum; placing an implant into the formed pathway and into contact with a lower vertebral body to be moved; affixing a sacral attachment onto the sacrum; applying a force so as to move and displace the implant and sacral attachment and the attached upper and lower vertebral bodies relative to one another.
Another method of placing and positioning a fusion implant is disclosed. The method Includes forming a curvilinear path within a first sacral vertebra wherein the pathway is centered about a point along a long axis of the L5 fastener placed into a pedicle portion of an L5 vertebral body. The path has a starting point between a portion of the facet joint and the posterior sacral foramen and transverses at least one sacral pedicle and at least a portion of the first sacral vertebral body and enters the disc space immediately superior to the sacrum. The method also includes positioning a fusion implant along the formed path.
Other features and advantages should be apparent from the following description of various embodiments, which illustrate, by way of example, the principles of the disclosed devices and methods.
The implant 105 is inserted into a pathway or is used to form a pathway through the aforementioned insertion site such that the pathway at least one sacral pedicle, a portion of the first sacral body and enters the L5/S1 disc space The pathway is preferably curvilinear—as shown in FIG. 4—and can be of uniform or non-uniform curvature. Alternatively, the pathway can be linear or substantially linear. The latter is particularly useful when an anterior spondylolisthesis (anterior displacement of the upper vertebra relative to the lower vertebra) of the L5 vertebral body is present relative to the sacrum.
The implant 105 can have a variety of structures. For example, the device can consist of a hollow cage having a shape that is adapted to transverse, at a minimum, the aforementioned sacral entry point, the sacral pedicle, the sacral body and then enter the disc space at the L5/S1 level.
The pathway for implant 105 placement can be formed in various ways. In one embodiment, a bone awl, drill or similar bone carving device of appropriate curvature is positioned at the sacral insertion site and used to forcefully form, such as by drilling or carving, the pathway through the sacral pedicle, sacral body and into the L5/S1 disc space (and possibly beyond). The implant 105 is guided into the carved pathway and the bone graft can be packed into the implant 105 before or after implantation. In another embodiment, a bone awl of curvature substantially similar to that of the implant (but of lesser diameter) is placed within the inner cavity of the implant. The tip of the awl extends beyond the end of the implant. The awl is forcefully guided through the bone so as to form the required pathway and place the implant in a single step. Alternatively, an awl-like tip can be incorporated directly onto the end of the implant.
In another embodiment, a pedicle bone screw 405 is placed into the L5 vertebral body and a guide is attached onto the screw head. The guide rotates in a curvilinear path until it rests immediately posterior to the sacral insertion site. Using the guide, a bone awl, drill or similar bone carving device of appropriate curvature is appropriately positioned by the guide at the sacral insertion site and used to forcefully form, such as by pushing, drilling or carving, the pathway through the sacral pedicle, sacral body and into the L5/S1 disc space (and possibly beyond). The implant 105 is then placed into the carved pathway and, as mentioned, the implant 105 can be filled with bone graft prior to or after implantation.
The sacral attachment 415 is then advanced into the sacrum S1 and attached onto one end of the implant 105. Alternatively, the sacral attachment 415 can be anchored into the sacrum S1 first and the implant 105 passed through a central bore within the sacral attachment 415.
Bone screw 405 preferably has a multi-axial rod receiving member 427 that can be rigidly affixed onto the spherical head 433 of the bone screw and an inter-connecting rod member 410. Multiple embodiments of this device are known in the art and can be used in this application. Alternatively, any adaptable bone screw can be used. Views of the assembled sacral attachment are shown in
When the locking nut 429 is appropriately tightened within bone screw 405 and sacral attachment 415, the construct members are rigidly affixed to one another. While the procedure can be preformed on one side, it is preferably performed on each side of the midline so as to provide complete bi-lateral fixation of both the anterior and posterior aspect of the sacrum and L5 vertebral body.
Devices and methods for the complete segmental fixation through a unilateral approach are shown in
In
As an alternative method of vertebral distraction, a pathway of appropriate curvature is formed as described above. An implant member 105 is placed into the formed pathway so that it abuts or attaches to the inferior surface of the L5 vertebral body (such as seen in
The disclosed devices or any of their components can be made of any biologically adaptable or compatible materials. Numerous materials are currently considered acceptable for biological implantation. They can include, but are not limited to, stainless steel, titanium, tantalum, combination metallic alloys, various plastics, resins, ceramics, biologically absorbable materials and the like. Any components can be also coated/made with osteo-conductive (such as demineralized bone matrix, hydroxyapatite, and the like) and/or osteo-inductive (such as Transforming Growth Factor “TGF-B,” Platelet-Derived Growth Factor “PDGF,” Bone-Morphogenic Protein “BMP,” and the like) bio-active materials that promote bone formation. Further, any surface can be made with a porous ingrowth surface (such as titanium wire mesh, plasma-sprayed titanium, tantalum, porous CoCr, and the like), provided with a bioactive coating, made using tantalum, and/or helical rosette carbon nanotubes (or other carbon nanotube-based coating) in order to promote bone in-growth or establish a mineralized connection between the bone and the implant, and reduce the likelihood of implant loosening. The system or any of its components can also be entirely or partially made of a shape memory material or other deformable material.
Although embodiments of various methods and devices are described herein in detail with reference to certain versions, it should be appreciated that other versions, embodiments, methods of use, and combinations thereof are also possible. Therefore the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.
Claims
1. A bone fusion implant adapted to be positioned between vertebral bodies in a human or animal subject, comprising:
- a curvilinear member sized and shaped to be positioned within a pathway in a first sacral vertebra along a trajectory that has a starting point between a portion of a facet joint and a posterior sacral foramen, that transverses at least one sacral pedicle and at least a portion of the first sacral vertebral body and that enters the disc space immediately superior to the sacrum.
2. An implant as in claim 1, wherein the implant is of uniform curvature.
3. An implant as in claim 1, wherein the implant is of non-uniform curvature.
4. An implant as in claim 1, wherein the implant is sized and shaped to transverse an L5 vertebral body and an L4/L5 disc space.
5. An implant as in claim 4, wherein the implant is sized and shaped to further transverse an L4 vertebral body.
6. An implant as in claim 1, wherein the implant comprises a cage with an inner space that accommodates a bone graft.
7. An implant as in claim 6, wherein the cage is at least partially manufactured from carbon nanotubes.
8. An implant as in claim 6, wherein the cage comprises at least one ridge, indentation, texture or feature within the cage or on a surface of the cage that is adapted to enhance anchorage into bone.
9. An implant as in claim 6, wherein the cage comprises at least one feature that is adapted to enhance bone incorporation or bone formation.
10. An implant as in claim 1, wherein the implant comprises a bone graft.
11. A bone fusion implant adapted to be positioned between vertebral bodies in a human or animal subject, comprising:
- a substantially straight member sized and shaped to be positioned within a pathway in a first sacral vertebra along a trajectory that has a starting point between a portion of a facet joint and a posterior sacral foramen, that transverses at least one sacral pedicle and at least a portion of the first sacral vertebral body and that enters the disc space immediately superior to the sacrum.
12. An implant as in claim 11, wherein the implant is sized and shaped to transverse an L5 vertebral body and an L4/L5 disc space.
13. An implant as in claim 12, wherein the implant is sized and shaped to further transverse an L4 vertebral body.
14. An implant as in claim 11, wherein the implant comprises a cage with an inner space that accommodates a bone graft.
15. An implant as in claim 14, wherein the cage is at least partially manufactured from carbon nanotubes.
16. An implant as in claim 14, wherein the cage comprises at least one ridge, indentation, texture or feature within the cage or on a surface of the cage that is adapted to enhance anchorage into bone.
17. An implant as in claim 14, wherein the cage comprises at least one feature that is adapted to enhance bone incorporation or bone formation.
18. An implant as in claim 11, wherein the implant comprises a bone graft.
19. A bone fusion implant adapted to be positioned between vertebral bodies in a human or animal subject, comprising:
- a curvilinear member sized and shaped to be positioned within a curvilinear pathway that joins at least two vertebral bodies wherein the implant at least partially contains a bone graft.
Type: Application
Filed: Mar 21, 2011
Publication Date: Jul 14, 2011
Inventor: Samy Abdou (San Diego, CA)
Application Number: 13/053,114