Facet arthoplasty devices and methods
View Patent ↗Surgically installed prostheses replace either the caudal portion of a natural facet joint, the cephalad portion of a natural facet joint, or both. The prostheses are readily attached to the pedicles of a vertebral body and support at least one element that defines an artificial facet joint structure. The caudal facet joint structure is sized and located to articulate with the cephalad facet joint structure. Together, the prostheses form a total facet replacement system. The system is suitable for use in virtually all levels of the spine.
1. A method of replacing at least a portion of a facet joint, the method comprising:
positioning a bar member against a vertebral body, the bar member comprising a left side region and a right side region, wherein the bar member comprises a track, and an opening is positioned in each of the left side region and the right side region of the bar member, and wherein a first facet joint structure element and a second facet joint structure element are each received within the track;
passing a first fixation element through the opening in the left side region and into a left pedicle of the vertebral body;
passing a second fixation element through the opening in the right side region and into a right pedicle of the vertebral body; and
adjusting one or more of the first facet joint structure element and the second facet joint structure element along the track to match a particular anatomy of the facet joint being replaced.
2. The method of claim 1 , wherein the first facet joint structure element is articulatable.
3. The method of claim 1 , wherein the bar member comprises a fixed length.
4. The method of claim 1 , wherein the bar member comprises a sliding joint.
5. The method of claim 1 , wherein one of the first and second facet joint structures is fixed to the bar member via welding or an adhesive.
6. The method of claim 1 , wherein the bar member is sized and shaped to span the distance between the left and right pedicles of the vertebral body.
7. The method of claim 1 , wherein the track is positioned along a midline of the bar member.
8. The method of claim 1 , wherein the first and second fixation elements are pedicle screws.
9. The method of claim 1 , wherein a distance of separation between the first facet joint structure and the second facet joint structure can vary.
10. The method of claim 1 , wherein a first set screw secures the first facet joint structure along the bar member and a second set screw secures the second facet joint structure along the bar member.
11. The method of claim 1 , wherein the first facet joint structure comprises a concave surface and the second facet joint structure comprises a concave surface.
12. The method of claim 11 , wherein the first concave surface and the second concave surface face each other.
13. The method of claim 1 , wherein the first facet joint structure comprises a convex surface and the second facet joint structure comprises a convex surface.
14. A method of replacing at least a portion of a facet joint, the method comprising:
securing a first end of a bar member to a first pedicle of the vertebral body by positioning a first fixation element through the first end of the bar member, wherein the bar member comprises a track;
securing a second end of a bar member to a second pedicle of the vertebral body by positioning a second fixation element through the second end of the bar member;
moving one or both of a first facet joint structure element positioned within the track and a second facet joint structure element positioned within the track, such that a distance of separation between the first facet joint structure and the second facet joint structure is adjustable.
15. The method of claim 14 , wherein the bar member has a fixed length.
16. The method of claim 14 , wherein the bar member has an adjustable length.
17. The method of claim 16 , wherein the bar member has a sliding joint.
18. The method of claim 14 , wherein the bar member is sized and shaped to span the distance between left and right pedicles of the vertebral body.
19. The method of claim 14 , wherein the first and second fixation elements are pedicle screws.
20. The method of claim 19 , wherein first facet joint structure comprises a first convex surface and the second facet joint structure element comprises a second convex surface that faces the first convex surface.