Spinal disc

• US 6,139,579 A
• Filed: 10/31/1997
• Issued: 10/31/2000
• Est. Priority Date: 10/31/1997
• Status: Expired due to Fees

• Current Assignee: Depuy Acromed Incorporated (Johnson & Johnson)
• Original Assignee: DePuy Motech Acromed Inc (Johnson & Johnson)
• Inventors: Ross, E. Raymond, Lowery, Gary L., Fraser, Robert D., Steffee, Arthur D.
• Primary Examiner(s): Milano, Michael J.
• Application Number:
  US08/962,578
• Time in Patent Office: 1,096 Days
• Field of Search: 623/17, 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 (16) of a human, includes a body (10) having an upper surface (52) engageable with the upper vertebra (12) and a lower surface (152) engageable with the lower vertebra (14). The body (10) includes a crescent-shaped projection (62, 162) extending from one of the upper and lower surfaces (52, 152) of the body for receipt in a cavity in the adjacent vertebra (12, 14).

Claims

1. A spinal disc prosthesis for replacing a damaged spinal disc in a spinal column of a human, said spinal disc prosthesis comprising;

a body for location between an upper vertebra and a lower vertebra of the spinal column;

said body having an upper surface engageable with the upper vertebra and a lower surface engageable with the lower vertebra; and

said body including a crescent-shaped projection extending from one of said upper and lower surfaces of said body for receipt in a cavity in the adjacent vertebra, said crescent-shaped projection having a crescent-shaped outer surface which is inclined relative to said one surface from which said projection extends.

2. The spinal disc of claim 1 wherein said outer surface of said projection is inclined by about 4 degrees relative to said one surface from which said projection extends.

3. The spinal disc of claim 1 wherein said crescent-shaped projection has a concave surface facing posteriorly of said spinal disc and a convex surface facing anteriorly of said spinal disc, said concave and convex surfaces terminating at opposite tips of said crescent-shaped configuration.

4. The spinal disc prosthesis of claim 3 wherein said outer surface of said projection is inclined by about 4 degrees relative to said one surface from which said projection extends.

5. The spinal disc of claim 1 wherein the distance between said one surface from which said projection extends and a central portion of said crescent-shaped projection is less than the distance between said one surface from which said projection extends and opposite tips of said crescent-shaped configuration.

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

an elastomeric core having upper and lower surfaces;

an upper rigid plate, said upper rigid plate having opposed first and second surfaces, said first surface being affixed to said upper surface of said elastomeric core; and

a lower rigid plate, said lower rigid plate having opposed third and fourth surfaces, said third surface being affixed to said lower surface of said elastomeric core;

said upper and lower rigid plates and said elastomeric core each having a perimeter defined by a flat portion and a curved portion which interconnects opposite ends of said flat portion, the perimeters of said first and second rigid plates and said elastomeric core being free of outwardly projecting lobes.

7. The spinal disc of claim 6 wherein said flat portions of said perimeters of said upper and lower rigid plates are disposed in a posterior portion of said spinal disc.

8. A spinal disc prosthesis for replacing a damaged spinal disc in a spinal column of a human, said spinal disc prosthesis comprising;

a body for location between an upper vertebra and a lower vertebra of the spinal column;

said body having an upper surface engageable with the upper vertebra and a lower surface engageable with the lower vertebra;

said body including a crescent-shaped projection extending from one of said upper and lower surfaces of said body for receipt in a cavity in the adjacent vertebra, said body including a second crescent-shaped projection extending from the other one of said upper and lower surfaces of said body for receipt in a cavity in the vertebra adjacent to said other surface; and

said body including an elastomeric core and an upper rigid plate having said upper surface of said body and a lower rigid plate identical to said upper rigid plate and having said lower surface of said body, said first crescent-shaped projection extending from said upper surface on said upper rigid plate, said second crescent-shaped projection extending from said lower surface on said lower rigid plate.

9. The spinal disc of claim 8 wherein the perimeters of said upper and lower rigid plates and of said elastomeric core are free of outwardly projecting lobes.

10. A spinal disc prosthesis for replacing a damaged spinal disc in a spinal column of a human, said spinal disc prosthesis comprising:

a body for location between an upper vertebra and a lower vertebra of the spinal column;

said body having an upper surface engageable with the upper vertebra and a lower surface engageable with the lower vertebra; and

a projection extending from one of said upper and lower surfaces of said body for receipt in a cavity in the adjacent vertebra;

said projection having a side surface extending generally perpendicular to said one surface from which said projection extends and a top surface inclined relative to said one surface from which said projection extends, said side surface and said top surface of said projection defining an edge on the anterior side of said spinal disc;

said side surface of said projection having a convex configuration.

11. The spinal disc of claim 10 wherein said projection has a crescent-shaped configuration.

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

a body for location between an upper vertebra and a lower vertebra of the spinal column;

said body having an upper surface engageable with the upper vertebra and a lower surface engageable with the lower vertebra; and

a projection extending from one of said upper and lower surfaces of said body for receipt in a cavity in the adjacent vertebra;

said projection having a side surface extending generally perpendicular to said one surface from which said projection extends and a top surface inclined relative to said one surface from which said projection extends, said side surface and said top surface of said projection defining an edge on the anterior side of said spinal disc;

said top surface projection inclining at an angle in the range of from about 2 degrees to about 6 degrees relative to said one surface from which said projection extends.

13. The spinal disc of claim 12 wherein said top surface of said projection is inclined at an angle of about 4 degrees relative to said one surface from which said projection extends.