Facet arthoplasty devices and methods
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 prosthetic system comprising:
a bar member comprising a left side region and a right side region, wherein the bar member comprises a track;
a first fixation area on the left side region;
a second fixation area on the right side region;
a first fixation element received in the first fixation area;
a second fixation element received in the second fixation area;
a first facet joint structure element positioned nearer to the first fixation area than the second fixation area; and
a second facet joint structure element positioned nearer to the second fixation area than the first fixation area, wherein the first facet joint structure and the second facet joint structure are each received within the track.
2. The system of claim 1 , wherein the first facet joint structure element is articulatable.
3. The system of claim 1 , wherein the bar element comprises a fixed length.
4. The system of claim 1 , wherein the bar element comprises a sliding joint.
5. The system of claim 1 , wherein the first facet joint structure is fixed to the bar member via welding or an adhesive.
6. The system of claim 1 , wherein the track is positioned along a midline of the bar member.
7. The system of claim 1 , wherein the distance of separation between the first facet joint structure and the second facet joint structure can vary.
8. The system 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.
9. The system of claim 1 , wherein the first facet joint structure comprises a concave surface and the second facet joint structure comprises a concave surface.
10. The system of claim 9 , wherein the first concave surface and the second concave surface face each other.
11. The system of claim 1 , wherein the first facet joint structure comprises a convex surface and the second facet joint structure comprises a convex surface.
12. A prosthetic system comprising:
a bar member comprising a left side region and a right side region, wherein the bar member comprises a track;
a first fixation element received through the left side region;
a second fixation element received through the right side region;
a first facet joint structure element positioned nearer to a first fixation area than a second fixation area; and
a second facet joint structure element positioned nearer to the second fixation area than the first fixation area, wherein the first facet joint structure element is positioned within the track and the second facet joint structure element is positioned within the track, wherein the first facet joint structure element is moveable along the track relative to the second facet joint structure,
wherein a distance of separation between the first facet joint structure and the second facet joint structure is adjustable.
13. The system of claim 12 , wherein the bar member has a fixed length.
14. The system of claim 12 , wherein the bar member has an adjustable length.
15. The system of claim 14 , wherein the bar member has a sliding joint.
16. The system of claim 12 , 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.