Supplementation or replacement of a nucleus pulposus of an intervertebral disc

• US 20060122704A1
• Filed: 07/27/2005
• Published: 06/08/2006
• Est. Priority Date: 07/27/2004
• Status: Abandoned Application

• Current Assignee: DePuy Synthes Products LLC (Johnson & Johnson)
• Original Assignee: Synthes, Inc. (Johnson & Johnson)
• Inventors: Keane, Michael F., Vresilovic, Edward, Schaer, Thomas P.
• Application Number:
  US11/189,753
• Publication Number:
  US 20060122704A1
• Time in Patent Office: Days
• US Class Current: 623/17.160
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• 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 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/2839 Bone plugs or bone graft dowels
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30242 spherical
• CPC Class Codes: A61F 2002/444 for replacing the nucleus pulposus
• CPC Class Codes: A61F 2002/4445 Means for culturing intervertebral disc tissue
• CPC Class Codes: A61F 2002/4627 with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument
• CPC Class Codes: A61F 2002/4631 the prosthesis being specially adapted for being cemented
• CPC Class Codes: A61F 2230/0069 cylindrical
• CPC Class Codes: A61F 2230/0071 spherical

Abstract

A degenerated nucleus pulposus located in a central core region of an intervertebral disc within the annulus fibrosus is supplemented or replaced by a method wherein an amount of a biocompatible material is introduced into the central core region by a process including the steps of 1) forming a channel through a vertebral body adjacent to said intervertebral disc, extending from an exterior surface of the vertebral body to the central core region of the annulus fibrosus; 2) introducing an amount of a biocompatible material through the channel into the central core region of the annulus fibrosus; 3) pressurizing the biocompatible material through the channel to a postsurgical pressure sufficient to alleviate symptoms caused by the degenerated nucleus pulposus; and 4) sealing the channel while maintaining the sufficient postsurgical pressure. After sealing the channel, a vertebroplasty may optionally be performed in the vertebra.

Claims

1. A method for replacing or supplementing a nucleus pulposus in an intervertebral disc, said intervertebral disc having an annulus fibrosus with a central core containing said nucleus pulposus, said method comprising:

forming a channel through a vertebral body adjacent to said intervertebral disc, said channel extending from an exterior surface of said vertebral body to said central core of said annulus fibrosus;

introducing an amount of a biocompatible material through said channel into said central core of said annulus fibrosus;

exerting pressure on said biocompatible material through said channel; and

sealing said channel while maintaining said pressure.

2. The method of claim 1, wherein said pressure is sufficient to at least approximately restore natural function of said intervertebral disc.

3. The method of claim 1, wherein said pressure is sufficient to at least approximately restore natural intervertebral spacing.

4. The method of claim 1, wherein said biocompatible material is pressurized to a pressure approximating natural pressure of the nucleus pulposus.

5. The method of claim 1, wherein said biocompatible material has a compressional modulus not greater than about 4 Mpa.

6. The method of claim 1, wherein said biocompatible material is a hydrogel.

7. The method of claim 6, wherein said hydrogel is comprised of a material selected from the group consisting of poly(vinyl alcohol) and an associating hydrogel that is a blend of poly(vinyl alcohol) and poly(vinylpyrrollidone).

8. The method of claim 1, wherein said biocompatible material is selected from the group consisting of a polyurethane and a silicone.

9. The method of claim 1, wherein said channel is sealed with a plug of a biocompatible sealing material.

10. The method of claim 9, wherein said biocompatible sealing material is selected from the group consisting of a bone cement, an autograft, an allograft, and a xenograft.

11. The method of claim 10, wherein said bone cement is selected from the group consisting of poly(methylmethacrylate), calcium phosphate, calcium sulfate, calcium carbonate, and hydroxyapatite

12. The method of claim 1, wherein said channel is sealed with a plug of biocompatible sealing material and a mechanical plug.

13. The method of claim 12, wherein said mechanical plug is selected from the group consisting of a bone screw and a barbed plug.

14. The method of claim 1, wherein said implant is pressurized by inserting a bone screw or a barbed plug into said channel.

15. The method of claim 1, additionally comprising a step of performing a vertebroplasty in said vertebral body after sealing said channel.

28. A restorative implant for an intervertebral disc implanted by the method of claim 1.

16. A restorative implant for an intervertebral disc comprising:

a quantity of a biocompatible material implanted in a central core of a human intervertebral disc replacing or supplementing a nucleus pulposus, said quantity of biocompatible material being accessible through a channel formed in an adjacent vertebra; and

a plug positioned in said channel and exerting pressure on said quantity of implanted low modulus material.

17. The implant of claim 16, wherein said postsurgical pressure is sufficient to at least approximately restore natural function of said intervertebral disc.

18. The implant of claim 16, wherein said postsurgical pressure is sufficient to at least approximately restore natural intervertebral spacing.

19. The implant of claim 16, wherein said biocompatible material is pressurized to a pressure approximating natural pressure of the nucleus pulposus.

20. The implant of claim 16, wherein said biocompatible material has a compressional modulus not greater than about 4 Mpa.

21. The implant of claim 16, wherein said biocompatible material has a Poisson ratio in a range of from about 0.30 to 0.50.

22. The implant of claim 26, wherein said biocompatible material is a hydrogel.

23. The implant of claim 22, wherein said hydrogel is a comprised of a material selected from the group consisting of poly(vinyl alcohol) and an associating hydrogel that is a blend of poly(vinyl alcohol) and poly(vinylpyrrollidone).

24. The implant of claim 16, wherein said biocompatible material is selected from the group consisting of a polyurethane and a silicone.

25. The implant of claim 16 additionally comprising a predetermined quantity of a generally incompressible material positioned in said channel between said implanted material and said plug.

26. The implant of claim 25 wherein said generally incompressible material is selected from the group consisting of bone cement, an autograft, an allograft, and a xenograft.

27. The implant of claim 16 wherein said plug is selected from the group consisting of a bone screw and a barbed plug.