Facet fusion implants and methods of use
An implant is insertable onto a vertebral facet joint includes a body with an inner surface that mates with one or both articular processes of the facet joint. The inner surface may define an interior cavity that accepts at least a portion of an inferior articular process and a superior articular process forming the facet joint. The body may be constructed of a bone growth material that fuses with the articular processes. The implant may help retain bone growth promoting substance that is inserted between or on articulating surfaces of the facet joint. A receiving portion of an exterior surface of one or both articular process may be prepared to stimulate bone growth. The implant may be placed onto the receiving portion to cover an exterior junction between or on the articulating surfaces of the facet joint. The implant may be secured to one or both of the articular processes.
1 . An implant for insertion onto a facet joint in a patient comprising:
a body including an inner bone-contact surface and an outer surface,
the bone-contact surface shaped to cover an exterior junction formed by articular processes of the facet joint, and
the body constructed of a graft material selected from a group consisting of autograft, allograft, and xenograft to fuse the processes together.
2 . The implant of claim 1 wherein the inner bone-contact surface is curved to match a contour of an exterior of the articular processes of the facet joint.
3 . The implant of claim 1 wherein the inner bone-contact surface is planar.
4 . An implant for insertion onto a facet joint in a patient comprising:
a body including an outer surface and an inner surface defining an interior cavity,
the body shaped to accept at least a portion of an inferior articular process and a superior articular process forming the facet joint,
the body constructed of a graft material selected from a group consisting of autograft, allograft, and xenograft to fuse with the inferior articular process and the superior articular process.
5 . The implant of claim 4 further comprising an aperture extending from the inner surface to the outer surface and sized to allow a bone fastener to pass.
6 . The implant of claim 4 wherein the body is substantially dome shaped.
7 . The implant of claim 4 wherein the interior cavity is rectangular.
8 . The implant of claim 4 wherein the interior cavity is cylindrical.
9 . An implant for insertion onto a facet joint in a patient comprising:
a body including an outer surface and an inner surface defining an interior cavity,
the body shaped to accept at least an exterior portion of a facet joint,
the body constructed of a graft material to fuse with the inferior articular process and the superior articular process.
10 . The implant of claim 9 wherein the graft material is selected from a group consisting of autograft, allograft, and xenograft.
11 . The implant of claim 9 wherein the graft material is at least partially constructed of calcium phosphate.
12 . A method of inserting an implant onto a facet joint in a patient, the method comprising the steps of:
placing the implant onto the facet joint with the implant covering an exterior junction formed by a first articulating surface of an inferior articular process and a second articulating surface of a superior articular process of the facet joint; and
causing the implant to osseointegrate to the inferior articular process and the superior articular process.
13 . The method of claim 12 wherein causing the implant to osseointegrate to the inferior articular process and the superior articular process comprises placing an implant constructed from a graft material onto a prepared exterior surface of one of the inferior articular process and the superior articular process.
14 . The method of claim 12 further comprising securing the implant to one of the inferior articular process and the superior articular process.
15 . The method of claim 14 wherein securing the implant comprises inserting a fastener through the implant and into one of the inferior articular process and the superior articular process.
16 . The method of claim 15 wherein the fastener is threaded.
17 . The method of claim 15 wherein the fastener is constructed of a graft material.
18 . The method of claim 12 wherein placing the implant onto the facet joint comprises covering a posterior interface formed by the inferior and superior articular processes.
19 . The method of claim 12 wherein placing the implant onto the facet joint comprises placing the implant between the facet joint and overlying fibrous tissue.
20 . A method of inserting an implant onto a facet joint in a patient, the method comprising the steps of:
preparing a receiving portion of an exterior surface other than an articulating surface of one of an inferior articular process and a superior articular process forming a facet joint;
placing the implant onto the receiving portion; and
causing the implant to osseointegrate to the one of the inferior articular process and the superior articular process.
21 . The method of claim 20 wherein placing the implant onto the receiving portion comprises covering a posterior interface formed by the inferior and superior articular processes.
22 . The method of claim 20 wherein preparing the receiving portion comprises decorticating the exterior surface of one of the inferior articular process and the superior articular process.
23 . The method of claim 20 wherein preparing the receiving portion comprises contouring the exterior surface of one of the inferior articular process and the superior articular process to substantially match a bone contact surface of the implant.
24 . The method of claim 20 wherein causing the implant to osseointegrate to one of the inferior articular process and the superior articular process comprises placing an implant constructed from a graft material onto the receiving portion.
25 . The method of claim 20 wherein causing the implant to osseointegrate to one of the inferior articular process and the superior articular process comprises placing an implant constructed at least partially from calcium phosphate onto the receiving portion.
26 . The method of claim 20 wherein causing the implant to osseointegrate to one of the inferior articular process and the superior articular process comprises securing the implant to one of the inferior articular process and the superior articular process.
27 . A method of inserting an implant onto a facet joint in a patient, the method comprising the steps of:
preparing a receiving portion of an exterior surface other than articulating surfaces of an inferior articular process and a superior articular process that form a facet joint;
placing a bone growth promoting substance onto the receiving portion and between the articulating surfaces of the facet joint;
placing the implant onto the receiving portion;
securing the implant to one of the inferior articular process and the superior articular process; and
causing the implant to osseointegrate to the inferior articular process and the superior articular process.
28 . The method of claim 27 wherein causing the implant to osseointegrate to the inferior articular process and the superior articular process comprises placing an implant constructed from a bone graft onto the receiving portion.
29 . The method of claim 27 wherein causing the implant to osseointegrate to the inferior articular process and the superior articular process comprises placing an implant constructed from calcium phosphate onto the receiving portion.
30 . The method of claim 27 wherein causing the implant to osseointegrate to the inferior articular process and the superior articular process comprises placing bone growth promoting substance between implant and the receiving portion.
31 . The method of claim 27 wherein securing the implant comprises inserting an elongated fastener through the implant and into one of the inferior articular process and the superior articular process.
32 . The method of claim 27 wherein placing the implant onto the receiving portion comprises placing the implant at a posterior side of the facet joint.
33 . The method of claim 27 wherein placing the implant onto the receiving portion comprises placing the implant at a lateral side of the facet joint.
34 . The method of claim 27 wherein placing the implant onto the receiving portion comprises placing the implant between the bone growth promoting substance and a fibrous tissue overlying the facet joint.
35 . The method of claim 27 wherein placing the implant onto the receiving portion comprises covering an exterior junction formed by the articulating surfaces of the facet joint.
36 . The method of claim 27 wherein placing the implant onto the receiving portion comprises protecting the bone growth promoting substance from compression by a fibrous tissue overlying the facet joint.
37 . The method of claim 27 wherein placing the implant onto the receiving portion comprises protecting the bone growth promoting substance from fibrous tissue invasion.