Flanged interbody fusion device with fastener insert and retaining ring
View Patent ↗Methods and devices are disclosed for treating the vertebral column. An integrated fixation plate and spacer having a retaining structure within the screw holes of the fixation plate to resist backout of screws attaching the fixation plate to the bone is provided. A movable joint may be provided between the fixation plate and spacer. In some embodiments, a screw hole insert is also provided to resist shear forces acting between the screw and fixation plate. In some embodiments, an integrated fixation plate and spacer system is provided, comprising two or more integrated fixation plate and spacer implants, wherein the fixation plates of each implant has a complementary configuration to allow attachment of the implants at adjacent intervertebral spaces. Alternative fixation systems are also contemplated.
1. An implant for treating the spine, comprising:
a stabilization plate comprising an access surface and a bone facing surface;
a first attachment lumen between the access surface and the bone facing surface of the stabilization plate, the first attachment lumen having a first attachment diameter adjacent to the access surface of the stabilization plate, a lumen surface, and a second attachment diameter adjacent to the bone facing surface of the stabilization plate;
a first lumen insert located at least partially in the first attachment lumen and having an inner insert surface and an outer insert surface, wherein the inner insert surface comprises a concave surface capable of accepting a range of anchor orientations within the first lumen insert, wherein the first lumen insert is configured to provide an intermediate layer of material between an anchor and the first attachment lumen; and
a feature configured to prevent the anchor from backing out of the first attachment lumen, the feature located closer to the access surface than the first lumen insert.
2. The implant for treating the spine as in claim 1 , wherein the feature is a retaining ring.
3. The implant for treating the spine as in claim 2 , wherein the retaining ring is configured to be positioned within a recess, wherein the recess is located between the access surface and the bone facing surface.
4. The implant for treating the spine as in claim 1 , wherein the feature is a blocking body comprising at least one biasing member.
5. The implant for treating the spine as in claim 4 , wherein the blocking body is configured to be positioned within an access space, wherein the access space is located between the access surface and the bone facing surface.
6. The implant for treating the spine as in claim 1 , wherein the feature is a locking plate.
7. The implant for treating the spine as in claim 6 , wherein the locking plate is configured to be positioned adjacent to the access surface and overlie at least a portion of the first attachment lumen.
8. The implant for treating the spine as in claim 1 , wherein the first lumen insert comprises a metallic or ceramic material.
9. The implant for treating the spine as in claim 1 , wherein the stabilization plate comprises a polymer material.
10. The implant for treating the spine as in claim 9 , wherein the first lumen insert comprises a metallic or ceramic material.
11. The implant for treating the spine as in claim 1 , wherein the first lumen insert is configured to absorb wear forces transmitted between the stabilization plate and the anchor.
12. The implant for treating the spine as in claim 1 , further comprising an anchor.
13. The implant for treating the spine as in claim 12 , wherein at least a portion of the first lumen insert is located between the stabilization plate and the anchor along an axis extending between the access surface and the bone facing surface.
14. The implant for treating the spine as in claim 13 , wherein the first lumen insert is configured to directly transmit forces transmitted between the stabilization plate and the anchor.
15. The implant for treating the spine as in claim 1 , wherein the outer insert surface is shaped to conform to at least a portion of the first attachment lumen.
16. The implant for treating the spine as in claim 1 , wherein the outer insert surface is convex.
17. The implant for treating the spine as in claim 1 , wherein the inner insert surface is shaped to conform to at least a portion of the anchor.
18. An implant for treating the spine, comprising:
a stabilization plate comprising an access surface and a bone facing surface;
a first attachment lumen between the access surface and the bone facing surface of the stabilization plate, the lumen having a first attachment diameter adjacent to the access surface of the stabilization plate, a lumen surface, and a second attachment diameter adjacent to the bone facing surface of the stabilization plate, wherein the first attachment diameter is greater than the second attachment diameter;
an anchor configured to be at least partially disposed in the first attachment lumen, the anchor comprising a head with an engaging surface facing the bone facing surface of the stabilization plate when disposed in the first attachment lumen; and
a first lumen insert configured to be at least partially disposed between the engaging surface of the anchor and the lumen surface to provide an intermediate layer of material,
wherein the anchor comprises an anchor orientation range allowing polyaxial movement of the anchor relative to the first lumen insert.
19. An implant for treating the spine, comprising:
a stabilization plate comprising an access surface and a bone facing surface;
a first attachment lumen between the access surface and the bone facing surface of the stabilization plate, the lumen having a first attachment diameter adjacent to the access surface of the stabilization plate, a lumen surface, and a second attachment diameter adjacent to the bone facing surface of the stabilization plate, wherein the first attachment diameter is greater than the second attachment diameter;
a first lumen insert configured to be at least partially disposed in the first attachment lumen; and
a retaining ring configured to be positioned within a recess, wherein the recess is located between the access surface and the bone facing surface, wherein the retaining ring is configured to prevent an anchor from backing out of the first attachment lumen, wherein the retaining ring abuts the first lumen insert.
20. The implant for treating the spine as in claim 18 , further comprising a feature configured to prevent the anchor from backing out of the first attachment lumen.