Intervertebral implant

• US 20040122518A1
• Filed: 12/19/2002
• Published: 06/24/2004
• Est. Priority Date: 12/19/2002
• Status: Active Grant

• Current Assignee: Hand Innovations LLC (Johnson & Johnson)
• Original Assignee: Synthes USA LLC (Johnson & Johnson)
• Inventors: Rhoda, William S.
• Granted Patent: US 7,192,447 B2
• Time in Patent Office: Days
• US Class Current: 623/17.11
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/30744 End caps, e.g. for closing an endoprosthetic cavity
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2/4465 having a circular or kidney shaped cross-section substantially perpendicular to the axis of the spine
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30133 kidney-shaped or bean-shaped
• CPC Class Codes: A61F 2002/3023 wedge-shaped cylinders
• CPC Class Codes: A61F 2002/30331 made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30599 stackable
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/30772 Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30843 Pyramidally-shaped
• CPC Class Codes: A61F 2002/4629 connected to the endoprosthesis or implant via a threaded connection
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2230/0015 : Kidney-shaped, e.g. bean-shaped
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2250/0063 : Nested prosthetic parts
• CPC Class Codes: A61F 2250/0098 : radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys

Abstract

An vertebral implant for fusing adjacent vertebrae or for replacing vertebral bodies is disclosed. The implant is a biocompatible metal, resorbable, or radiolucent implant conforming substantially in size and shape with an end plate of a vertebra. The implant preferably has a wedge-shaped profile to restore disc height and the natural curvature of the spine. The top and bottom surfaces of the implant have areas with a plurality of teeth to resist expulsion and provide initial stability and areas devoid of any protrusions to receive implantation instrumentation. The implant also has a stackability feature. The implant provides initial stability needed for fusion without stress shielding.

Claims

1. An intervertebral implant comprising a body having a convexly curved anterior side substantially opposing a concavely curved posterior side spaced apart by first and second convexly curved lateral sides to define a central bore, the body further having top and bottom surfaces, each of the top and bottom surfaces are configured to contact an adjacent vertebrae and the outer periphery of the top and bottom surfaces substantially conform in size and shape with the end plates of adjacent vertebra, and wherein each of the top and bottom surfaces have areas extending from their outer periphery to the central bore having a plurality of gripping structures for engaging the end plates of adjacent vertebra and have areas extending from their outer periphery to the central bore that are substantially smooth for receiving a surgical instrument.

2. The implant of claim 1, wherein the radius of curvature of the convexly curved anterior side and the pair of convexly curved lateral sides is substantially the same.

3. The implant of claim 1, wherein at least one side has a channel for receiving a surgical instrument.

4. The implant of claim 3, wherein the channel runs in at least an anterior-posterior direction or a lateral direction.

5. The implant of claim 1, wherein at least one side of the implant has at least a threaded hole for attachment of an inserter.

6. The implant of claim 5, wherein the hole is located on the anterior side of the implant and at least one of the lateral sides of the implant.

7. The implant of claim 1, wherein the top and bottom surfaces are convexly curved surfaces from the anterior side to the posterior side.

8. The implant of claim 1, wherein the top and bottom surfaces are convexly curved surfaces from the first lateral side to the second lateral side.

9. The implant of claim 7, wherein the top and bottom surfaces are convexly curved surfaces from the first lateral side to the second lateral side.

10. The implant of claim 1, wherein the top and bottom surfaces are substantially flat planar surfaces having a downward taper at an anterior end of the implant and at a posterior end of the implant to facilitate insertion of the implant.

11. The implant of claim 10, wherein the downward taper extends along the entire periphery of the top surface and the bottom surface.

12. The implant of claim 1, wherein the central bore of the implant is configured and adapted to receive an osteoconductive material.

13. The implant of claim 1, wherein the areas of the top and bottom surfaces of the implant which are substantially smooth extend in at least one of a lateral direction, an anterior-posterior direction, or an anterio-lateral direction.

14. The implant of claim 1, wherein the implant is made from a biocompatible metal.

15. The implant of claim 1, wherein the implant is made from a radiolucent material.

16. The implant of claim 15, wherein the implant further comprises a radiopaque marker.

17. The implant of claim 1, wherein the implant is made from a resorbable material.

18. The implant of claim 1, wherein the implant has at least one bore transverse to the central bore extending from a side of the body to the central bore.

19. The implant of claim 1, wherein the profile of the implant is substantially wedge-shaped.

20. The implant of claim 1, wherein the implant is formed of end caps.

21. The implant of claim 1, wherein the implant is formed of end caps and at least one body portion.

22. An intervertebral implant for insertion between two vertebral bodies in a spinal column comprising a substantially kidney bean shaped body having a central bore and at least one channel transverse to the central bore extending from a side of the body to the central bore, the body sized and shaped to substantially conform to end plates of adjacent vertebral bodies and having a substantially convex upper and lower surface for approximating the contours of the end plates of adjacent vertebra, wherein the top and bottom surfaces of the implant have areas extending from a periphery of the implant to the central bore having a plurality of teeth for engaging the end plates of adjacent vertebra and areas extending from the periphery of the implant to the central bore having no teeth for receiving a surgical instrument,

23. The implant of claim 22, wherein a threaded hole for attachment of an inserter is provided on at least one of the longitudinal or lateral sides of the implant.

24. An intervertebral implant comprising:

a first endcap having an upper surface configured to contact an adjacent vertebrae and a lower surface;

a second endcap having a lower surface configured to contact an adjacent vertebrae and an upper surface; and

at least one body portion having an upper and lower surface,

wherein the upper surface of the body portion is designed and configured to be coupled to the lower surface of the first endcap or the lower surface of another body portion, and the lower surface of the body portion is designed and configured to be coupled to the upper surface of the second end cap or the upper surface of another body portion.

25. The implant of claim 24, wherein the upper surface of the first endcap and the lower surface of the second endcap each have areas having a plurality of gripping structures for engaging the end plates of adjacent vertebra and have areas that are substantially smooth for receiving a surgical instrument.

26. The implant of claim 24, wherein the first endcap and the second endcap each have at least one elongated bore for receiving bone growth inducing materials.

27. The implant of claim 24, wherein the first endcap, the second endcap, and the at least one body portion have at least one hole for receiving a fixation member.

28. The implant of claim 24, wherein the body portion further comprises a channel for receiving a surgical instrument.

29. The implant of claim 28, wherein the channel runs in an anterior-posterior direction.

30. The implant of claim 28, wherein the channel runs in a lateral direction.

31. The implant of claim 24, wherein at least one side of the body portion further has at least one threaded hole for attachment of an inserter.

32. The implant of claim 31, wherein the hole is located on the anterior side of the body portion and at least one of the lateral sides of the body portion.

33. The implant of claim 24, wherein the upper surface of the first endcap and the lower surface of the second endcap are convexly curved surfaces.

34. The implant of claim 33, wherein the upper surface of the first endcap and the lower surface of the second endcap are curved surfaces to mimic the end plates of the adjacent vertebra.

35. The implant of claim 24, wherein the area of the upper surface of the first endcap and the area of the lower surface of the second endcap which are substantially smooth extend in at least one of a lateral direction, an anterior-posterior direction, or an anterio-lateral direction.

36. The implant of claim 24, wherein the first endcap, the second endcap, and at least one body portion have a convexly curved anterior side substantially opposing a concavely curved posterior side spaced apart by a pair of convexly curved lateral sides.

37. The implant of claim 24, wherein the lower surface of the first endcap has a protrusion, the upper surface of the second endcap has a shoulder defining a cavity and the upper surface of the body portion has a shoulder defining a cavity configured to couple with the protrusion of the first end cap or another body portion and the lower surface of the body portion has a protrusion configured to couple with the cavity of the second end cap or another body portion.

38. The implant of claim 24, wherein the lower surface of the first endcap has a protrusion and a shoulder defining a cavity and the upper surface of the body portion has a shoulder defining a cavity and a protrusion configured to couple with the protrusion and cavity of the first end cap or another body portion and the lower surface of the body portion has a protrusion and cavity configured to couple with the cavity and protrusion of the second end cap or another body portion.

39. An intervertebral implant comprising:

a first endcap having an upper surface configured to contact an adjacent vertebrae and a lower surface having a protrusion and a shoulder defining a cavity; and

a second endcap having a lower surface configured to contact an adjacent vertebrae and an upper surface having a protrusion and a shoulder defining a cavity,

wherein the protrusion and cavity located on the upper surface of the second endcap is designed and configured to be coupled to cavity and protrusion located the lower surface of the first endcap.