Intervertebral implant with conformable endplate

• US 10,433,974 B2
• Filed: 11/23/2015
• Issued: 10/08/2019
• Est. Priority Date: 06/30/2003
• Status: Active Grant

• Current Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Inventors: O'Neil, Michael J.
• Primary Examiner(s): Robert, Eduardo C
• Assistant Examiner(s): Eckman, Michelle C
• Application Number:
  US14/949,364
• Publication Number:
  US 20160074175A1
• Time in Patent Office: 1,415 Days
• Field of Search: 623 1711- 1716
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• 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 2/4425 made of articulated components
• CPC Class Codes: A61F 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• CPC Class Codes: A61F 2002/30014 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2002/30016 differing in hardness, e.g. Vickers, Shore, Brinell
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30769 madreporic
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30891 Plurality of protrusions
• CPC Class Codes: A61F 2250/0018 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0019 differing in hardness, e.g. Vickers, Shore, Brinell
• CPC Class Codes: A61F 2310/00017 Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00029 Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00401 Coating made of iron, of stainless steel or of other Fe-based alloys
• CPC Class Codes: A61F 2310/00407 Coating made of titanium or of Ti-based alloys
• CPC Class Codes: A61F 2310/00796 Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite
• CPC Class Codes: A61F 2310/00976 Coating or prosthesis-covering structure made of proteins or of polypeptides, e.g. of bone morphogenic proteins BMP or of transforming growth factors TGF

Abstract

The invention is generally related to an intervertebral implant for replacing an intervertebral disc of the human spine. The intervertebral implant includes a first conformable endplate, the first conformable endplate being conformable to a boney vertebral endplate under an anatomical load, a second endplate and a core between the endplates, wherein the first conformable endplate partitions the core from the boney vertebral endplate, whereby the core does not contact the boney vertebral endplate. The invention is also directed to a method of replacing an intervertebral disc. The method includes removing at least a portion of an intervertebral disc to form an intervertebral disc space, implanting a first conformable endplate, into the intervertebral disc space and in contact with a first honey vertebral endplate, the first conformable endplate being conformable to the first boney vertebral endplate under an anatomical load; implanting a second endplate into the intervertebral disc space and in contact with a second boney vertebral endplate; and implanting a core between the first conformable endplate and the second endplate, wherein the first conformable endplate partitions the core from the first boney vertebral endplate, whereby the core does not contact the first boney vertebral endplate.

Claims

1. An intervertebral implant, comprising:

a first endplate comprising a textured polymeric bone-contacting surface coated with titanium;

a second endplate comprising a textured polymeric bone-contacting surface coated with titanium; and

a core disposed between the endplates;

a rigid plate disposed between the core and the first endplate, the rigid plate configured to partition the core from the first endplate such that the core does not contact the first endplate,

wherein, when the implant is inserted into an intervertebral space between first and second boney vertebral endplates, the first endplate is configured to partition the core from the first boney vertebral endplate such that the core does not contact the first boney vertebral endplate and the second endplate is configured to partition the core from the second boney vertebral endplate such that the core does not contact the second boney vertebral endplate; and

wherein the core is configured to support first and second boney vertebral endplates between which the implant is placed and wherein the implant is a rigid fusion cage.

2. The implant of claim 1, wherein the core comprises a rigid matrix.

3. The implant of claim 1, wherein the core is osteoinductive.

4. The implant of claim 1, wherein the core comprises struts inter-packed with bone.

5. The implant of claim 1, wherein the first and second endplates are conformable to boney vertebral endplates under anatomical load.

6. The implant of claim 1, wherein the entire bone-contacting surface of the first endplate is conformable and the entire bone-contacting surface of the second endplate is conformable.

7. The implant of claim 1, wherein the titanium comprises at least one of a titanium alloy and commercially pure titanium.

8. The implant of claim 1, wherein the titanium has a thickness between 0.0625 mm and 1 mm.

9. The implant of claim 1, wherein the titanium has a thickness between 0.0625 mm and 6.35 inches.

10. The implant of claim 1, wherein the core comprises plastic.

11. The implant of claim 1, wherein the core comprises high density polyethylene.

12. The implant of claim 1, wherein the first and second endplates are separate.

13. The implant of claim 1, wherein the bone-contacting surface of the first endplate extends in a superior direction beyond a superior-most end of the rigid plate.

14. The implant of claim 1, further comprising:

a second rigid plate, the second rigid plate disposed between the core and the lower endplate such that the core does not contact the lower endplate,

wherein each of the first endplate, the second endplate, the first rigid plate, the second rigid plate, and the core form a layer of the implant and each layer has an equal perimeter.

15. A spinal fusion cage, comprising:

a load-bearing core configured to support anatomical loads;

an upper endplate disposed above the core and having a textured polymeric surface coated with titanium;

a rigid plate disposed between the core and the upper endplate, the rigid plate configured to partition the core from the upper endplate such that the core does not contact the upper endplate; and

a lower endplate disposed below the core and having a textured polymeric surface coated with titanium;

wherein the load-bearing core comprises a rigid cage.

16. The fusion cage of claim 15, wherein the upper and lower endplates are conformable to boney vertebral endplates under anatomical load.

17. The fusion cage of claim 15, wherein an entire bone-facing surface of the upper endplate is conformable and wherein an entire bone-facing surface of the lower endplate is conformable.

18. The fusion cage of claim 15, wherein the core comprises struts inter-packed with bone.

19. The fusion cage of claim 15, wherein the titanium comprises at least one of a titanium alloy and commercially pure titanium.

20. The fusion cage of claim 15, wherein the upper endplate, the lower endplate, the core, and the rigid plate each have a perimeter of a same size and shape.

21. A spinal fusion cage, comprising:

a load-bearing core configured to support anatomical loads;

an upper endplate disposed above the core and having a textured polymeric surface coated with titanium;

a rigid plate disposed between the core and the upper endplate, the rigid plate configured to partition the core from the upper endplate such that the core does not contact the upper endplate; and

a lower endplate disposed below the core and having a textured polymeric surface coated with titanium;

wherein the load-bearing core is a rigid matrix.

22. The fusion cage of claim 21, wherein the cage has a single continuous contour formed by the upper endplate, the lower endplate, the core, and the rigid plate.