Artificial spinal disc

• US 6,162,252 A
• Filed: 12/12/1997
• Issued: 12/19/2000
• Est. Priority Date: 12/12/1997
• Status: Expired due to Term

• Current Assignee: Depuy Acromed Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Acromed Incorporated (Johnson & Johnson)
• Inventors: DiNello, Alexandre M., McMillin, Carl R., Kuras, James M.
• Primary Examiner(s): Millin, V.
• Assistant Examiner(s): Phan, Hieu
• Application Number:
  US08/991,224
• Time in Patent Office: 1,103 Days
• Field of Search: 623/17, 623/17.11, 623/17.12, 623/17.13, 623/17.14, 623/17.15, 623/17.16, 623/16.11, 606/61
• US Class Current: 623/17.16
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• 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 2002/30069 elastomeric
• CPC Class Codes: A61F 2002/30112 Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2002/30131 horseshoe- or crescent- or C-shaped or U-shaped
• CPC Class Codes: A61F 2002/30187 D-shaped or half-disc-shaped
• CPC Class Codes: A61F 2002/3023 wedge-shaped cylinders
• CPC Class Codes: A61F 2002/30563 having elastic means or damping means, different from springs, e.g. including an elastomeric core or shock absorbers
• CPC Class Codes: A61F 2002/30574 with an integral complete or partial collar or flange
• CPC Class Codes: A61F 2002/30769 madreporic
• CPC Class Codes: A61F 2002/30805 Recesses of comparatively large area with respect to their low depth
• CPC Class Codes: A61F 2002/30878 with non-sharp protrusions, for instance contacting the bone for anchoring, e.g. keels, pegs, pins, posts, shanks, stems, struts
• CPC Class Codes: A61F 2002/30879 Ribs
• CPC Class Codes: A61F 2002/30884 Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity
• CPC Class Codes: A61F 2002/30957 using a positive or a negative model, e.g. moulds
• CPC Class Codes: A61F 2002/30967 Diffusion bonding
• CPC Class Codes: A61F 2230/0004 Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2230/0034 D-shaped
• CPC Class Codes: A61F 2230/0069 cylindrical
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00407 : Coating made of titanium or of Ti-based alloys

Abstract

A spinal disc prosthesis to replace a damaged spinal disc in a spinal column of a human includes an upper rigid plate having an outer perimeter and a lower rigid plate having an outer perimeter. A body of elastomeric material located between and bonded to the upper and lower rigid plates includes a main portion and a peripheral portion extending around the main portion. The upper and lower plates each have a curved convex plate surface extending around the respective outer perimeters and facing the peripheral portion of the body of elastomeric material. The peripheral portion of the body of elastomeric material has a first part which is bonded to the curved convex plate surfaces of the upper and lower plates and extends toward the main portion. The first part of the peripheral portion increases in thickness as the first part extends from the curved convex plate surfaces toward the main portion. The first part of the peripheral portion of the body of elastomeric material has a convexly curved outer surface which forms a part of the outer surface of the body of elastomeric material.

Claims

1. A spinal disc prosthesis to replace a damaged spinal disc in a spinal column of a human, said spinal disc prosthesis comprising:

an upper rigid plate having an outer perimeter;

a lower rigid plate having an outer perimeter;

a body of elastomeric material located between and bonded to said upper and lower rigid plates, said body of elastomeric material including a main portion and a peripheral portion extending around said main portion;

said upper and lower plates each having a curved convex plate surface extending around said respective outer perimeters and facing said peripheral portion of said body of elastomeric material;

said peripheral portion of said body of elastomeric material having a first part which is bonded to said curved convex plate surfaces of said upper and lower plates and extends toward said main portion, said first part of said peripheral portion increasing in thickness as said first part extends from said curved convex plate surfaces toward said main portion;

said first part of said peripheral portion of said body of elastomeric material having a convexly curved outer surface which forms a part of the outer surface of said body of elastomeric material.

2. A spinal disc prosthesis as set forth in claim 1 wherein each one of said upper and lower plates has a respective rim which encircles said plate and which is bonded to said main portion of said body of elastomeric material.

3. A spinal disc prosthesis as set forth in claim 2 wherein said upper and lower plates each have a flat surface portion extending from said rim toward said curved convex plate surface, said peripheral portion of said body of elastomeric material being bonded to said flat surfaces.

4. A spinal disc prosthesis as set forth in claim 3 wherein said peripheral portion has an increasing thickness as it extends from said curved surfaces toward said flat surfaces and has a decreasing thickness as it extends from said flat surfaces toward said main portion.

5. A spinal disc prosthesis as set forth in claim 2 wherein said rims of said upper and lower plates define the outer perimeter of said main portion of said body of elastomeric material.

6. A spinal disc prosthesis as set forth in claim 5 wherein said rims of said upper and lower plates have curved outer surfaces which are bonded to said main portion of said body of elastomeric material.

7. A spinal disc prosthesis as set forth in claim 1 wherein said peripheral portion of said body of elastomeric material overlies respective flat surfaces on said upper and lower plates and overlies respective rims which encircle said plates and which are bonded to said main portion of said body of elastomeric material.

8. A spinal disc prosthesis as set forth in claim 7 wherein said peripheral portion has an increasing thickness as it extends from said curved surfaces toward said flat surfaces and has a decreasing thickness as it extends from said flat surfaces toward said main portion.

9. A spinal disc prosthesis as set forth in claim 1 wherein said main portion of said body of elastomeric material has a substantially uniform thickness across its entire extent, said peripheral portion of said body of elastomeric material having a thickness which varies as it extends outward in a direction away from said main portion of said body of elastomeric material.

10. A spinal disc prosthesis as set forth in claim 1 wherein said upper plate has an inner major side surface presented toward an inner major side surface of said lower plate, each one of said inner major side surfaces including a rim which extends around a planar first surface having an area which is at least about 90% of the area of said respective inner major side surface, said first surfaces and said rims defining the axial ends of said main portion of said body of elastomeric material.

11. A spinal disc prosthesis as set forth in claim 1 wherein each one of said upper and lower plates has a generally planar vertebral contact surface which extends outward of said main portion of said body of elastomeric material, said curved convex surfaces of said upper and lower plates being disposed outward of said vertebral contact surfaces.

12. A spinal disc prosthesis to replace a damaged spinal disc in a spinal column of a human, said spinal disc prosthesis comprising:

an upper rigid plate having an outer perimeter;

a lower rigid plate having an outer perimeter;

a body of elastomeric material located between and bonded to said upper and lower rigid plates, said body of elastomeric material including a main portion and a peripheral portion extending around said main portion;

said upper and lower plates each having a rim which encircles said plate and which is bonded to said main portion of said body of elastomeric material;

said upper and lower plates each having a curved convex plate surface extending around said outer perimeters and facing said peripheral portion of said body of elastomeric material;

said peripheral portion of said body of elastomeric material having a first part which is bonded to said curved surfaces of said upper and lower plates and extends toward said main portion, said first part of said peripheral portion increasing in thickness as said first part extends from said curved surfaces toward said main portion;

said upper and lower plates each having a flat surface extending from said curved convex plate surface toward said rim, said peripheral portion of said body of elastomeric material being bonded to said flat surfaces, said peripheral portion having an increasing thickness as it extends from said curved convex plate surfaces toward said flat surfaces and having a decreasing thickness as it extends from said flat surfaces toward said rims.

13. A spinal disc prosthesis as set forth in claim 12 wherein said body of elastomeric material has an outer surface with an hourglass-shaped configuration which is widest at said curved convex surfaces of said upper and lower plates.

14. An artificial spinal disc comprising:

upper and lower plates, each having an outer perimeter and a flange extending about the outer perimeter, and

an elastomeric body located between the upper and lower plates, the body including a main portion and a peripheral portion extending about the main portion adjacent to each flange, the peripheral portion having an outer surface, a portion of which is convexly curved.

15. The disc of claim 14, wherein the peripheral portion increases in thickness as the peripheral portion extends from the flanges toward the main portion of the body.

16. The disc of claim 14, wherein each flange includes a curved convex plate surface facing the peripheral portion.

17. The disc of claim 16, wherein each plate includes a rim spaced-apart from the respective curved convex plate surface.

18. The disc of claim 17, wherein the rim is bonded to the main portion of the body.

19. The disc of claim 17, wherein each rim defines an outer perimeter of the main portion of the body.

20. The disc of claim 14, wherein the main portion of the body has a substantially uniform thickness across its entire extent.

21. The disc of claim 14, wherein each plate includes an inner major side surface that has a rim which extends around a first surface having an area which is at least about 90% of the area of the respective inner major side surface.

22. The disc of claim 21, wherein the first surfaces and the rims define the axial ends of the main portion of the body.

23. The disc of claim 14, wherein each plate has a generally planar vertebral contact surface which extends outward of the main portion of the body.

24. An artificial spinal disc comprising:

upper and lower plates, each having a rim, an outer perimeter spaced-apart from the rim, and a flange extending about the outer perimeter, and

an elastomeric body located between the upper and lower plates and engaging the rims, the body including a main portion and a peripheral portion extending about the main portion adjacent to each flange, the peripheral portion varying in thickness as it extends between each flange and each rim.

25. The spinal disc of claim 24, wherein the peripheral portion includes an outer surface, a portion of which is convexly curved.

26. The spinal disc of claim 24, wherein the peripheral portion includes a first part that increases in thickness as it extends from the flange toward the main portion of the body.

27. The spinal disc of claim 24, wherein each flange includes a curved plate surface and a generally flat surface extending from the curved plate surface toward the rim.

28. The spinal disc of claim 27, wherein the peripheral portion increases in thickness as it extends from the curved plate surfaces toward the flat surfaces.

29. The spinal disc of claim 28, wherein the peripheral portion decreases in thickness as it extends from the flat surfaces toward the rims.

30. The spinal disc of claim 24, wherein the body has an hourglass-shaped outer surface.