PROSTHESES SYSTEMS AND METHODS FOR REPLACEMENT OF NATURAL FACET JOINTS WITH ARTIFICIAL FACET JOINT SURFACES
Cephalad and caudal vertebral facet joint prostheses and methods of use are provided. A pair of fixation elements are adapted to be secured within a vertebra in an orientation that best assures a secure and durable attachment to cortical and/or cancellous bone. Artificial facet joint surfaces are mounted on the fixation elements, either directly or with the aid of a support. The artificial facet joint structure may be carried by an arm. The artificial facet joint structure is adapted for articulation with a complementary natural or artificial facet joint structure. Bilateral prostheses may by coupled by a brace to further secure and stabilize the prostheses.
1 . An implant for stabilizing the spine, comprising:
a first member adapted to rigidly couple to a first vertebra and having a lumen extending therethrough;
a second member adapted to movably couple to a second vertebra, the second member being slidably disposed through and movable relative to the first member;
wherein the first and second members are adapted to control movement of first and second vertebrae coupled thereto.
2 . The implant of claim 1 , wherein the first member comprises a first lateral portion having a lumen extending therethrough, a second lateral portion having a lumen extending therethrough, and a connecting member extending between and coupled to the first and second lateral portions.
3 . The implant of claim 2 , wherein the second member comprises a first pin member slidably disposed through the first lateral portion, and a second pin member slidably disposed through the second lateral portion.
4 . The implant of claim 3 , wherein the first pin member includes a head formed on a first terminal end thereof and adapted to be received within a portion of the lumen in the first lateral portion, and wherein the second pin member includes a head formed on a first terminal end thereof and adapted to be received within a portion of the lumen in the second lateral portion.
5 . The implant of claim 4 , wherein the lumens in the first and second lateral portions each include stop formed therein and adapted to limit slidably movement of the head of the pin member.
6 . The implant of claim 4 , wherein a second terminal end of each of the first and second pin members includes a spherical member formed thereon and adapted to be rotatably coupled to a fastening element for movably coupling the first and second pin members to a second vertebra.
7 . The implant of claim 2 , wherein the connecting member comprises an elongate bar having opposed terminal ends that are adapted to mate to the first and second lateral portions.
8 . An implant for stabilizing the spine, comprising:
a first member having a first portion adapted to rigidly couple to a first vertebra, and a second portion slidably movable with respect to the first portion and adapted to couple to a second vertebra;
a second member having a first portion adapted to rigidly couple to a first vertebra, and a second portion slidably movable with respect to the first portion and adapted to couple to a second vertebra;
and a connecting member extending between and coupled to the first and second members.
9 . The implant of claim 8 , wherein the second portion of each of the first and second members comprises a pin member that is slidably disposed through the first portion.
10 . The implant of claim 9 , wherein each pin member includes a head that is adapted to be received within a lumen formed in the first portion of each of the first and second members, and wherein each lumen includes an enlarged diameter region adapted to receive the head of the pin member.
11 . The implant of claim 8 , wherein the first portion of each of the first and second members includes an offset connector formed thereon and adapted to mate to the connecting member.