Artificial disc prosthesis

• US 20060149384A1
• Filed: 02/24/2006
• Published: 07/06/2006
• Est. Priority Date: 04/04/2003
• Status: Abandoned Application

• Current Assignee: Theken Disc, LLC (Integra LifeSciences Holdings Corporation)
• Original Assignee: Theken Disc, LLC (Integra LifeSciences Holdings Corporation)
• Inventors: Theken, Randall R., Navarro, Richard R., Ananthan, Bharadwaj
• Application Number:
  US11/361,621
• Publication Number:
  US 20060149384A1
• Time in Patent Office: Days
• US Class Current: 623/17.140
• 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 2002/30372 with additional means for limiting said translation
• CPC Class Codes: A61F 2002/30383 made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove
• CPC Class Codes: A61F 2002/30462 retained or tied with a rope, string, thread, wire or cable
• 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 2002/30604 modular
• CPC Class Codes: A61F 2002/30884 Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity
• CPC Class Codes: A61F 2002/30892 parallel
• CPC Class Codes: A61F 2002/30904 serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/3097 using laser
• CPC Class Codes: A61F 2002/4666 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61F 2220/0025 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• 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 2220/0075 sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• 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

Abstract

A visco-elastic motion-limiting artificial intervertebral disc prosthesis is provided that mimics the physiologic function of a normal spinal disc. The disc comprises upper and lower endplates having therewithin channels or openings for optionally receiving one or more motion-limiting members fitted on each end with an enlarged portion. One or more compression stops is provided between the upper and lower endplates. Additionally, an elastomeric cushion is disposed between the endplates and surrounds the motion-limiting members. Also, force transducers and microelectronics can be utilized to provide data to the surgeon or the patient regarding the load state of the disc.

Claims

1. A spinal disc prosthesis, comprising:

a first endplate and a second endplate each suitable to attach to respective vertebrae;

a first member interposed between and adhered to said first and second endplates, wherein said first member is capable of carrying compressive load from said first endplate to said second endplate; and

a second member or set of members which,

at a sufficiently large compression of said prosthesis, establishes contact suitably to transfer compressive load from said first endplate to said second endplate, and,

at a sufficiently small compression of said prosthesis, does not establish contact suitably to transfer compressive load from said first endplate to said second endplate.

2. The prosthesis of claim 1, wherein, at said sufficiently small compression of said prosthesis, said second member or set of members exhibits a gap.

3. The prosthesis of claim 1, wherein said second members or set of members comprises a protrusion on said first endplate.

4. The prosthesis of claim 3, wherein said second endplate comprises a stop.

5. The prosthesis of claim 3, wherein said second endplate does not comprise a stop.

6. The prosthesis of claim 1, wherein said first member comprises polymeric material, and said second member or set of members comprises metal.

7. A spinal disc prosthesis, comprising:

a first endplate and a second endplate each suitable to attach to respective vertebrae;

a first member interposed between and adhered to said first and second endplates, wherein said first member reacts against any flexion; and

a second member or set of members which,

at a sufficiently large flexion of said prosthesis, establishes contact suitably to react against flexion, and

at a sufficiently small flexion of said prosthesis, does not establish contact suitably to react against flexion.

8. The prosthesis of claim 7, wherein, at said sufficiently small flexion of said prosthesis, said second member or set of members exhibits a gap.

9. The prosthesis of claim 7, wherein said second member or set of members comprises a first element that is capable of carrying a compressive load between said first and second endplates and a second element that is capable of carrying a tensile load between said first and second endplates.

10. The prosthesis of claim 7, wherein said first member comprises polymeric material, and said second member or set of members comprises metal.

11. A spinal disc prosthesis, comprising:

a first endplate and a second endplate each suitable to attach to respective vertebrae;

a polymeric member interposed between and adhered to said first and second endplates; and

a metal member or set of members which, at a sufficiently large externally applied load, forms a load path suitable to carry a portion of at least some component of load between said first endplate and said second endplate, and, at a sufficiently small externally applied load, does not form a load path between said first endplate and said second endplate.

12. The prosthesis of claim 11, wherein, at said sufficiently small externally applied load, said metal members or set of members exhibit a gap.

13. The prosthesis of claim 11, wherein said metal member or set of members is capable of carrying a compressive load.

14. The prosthesis of claim 13, wherein said metal member or set of members comprises a protrusion connected to said first endplate suitable to contact said second endplate.

15. The prosthesis of claim 13, wherein said metal member or set of members comprises a protrusion connected to said first endplate and a stop connected to said second endplate, said protrusion being suitable to contact said stop.

16. The prosthesis of claim 11, wherein said metal member or set of members comprises a member that is capable of carrying a tensile load.

17. The prosthesis of claim 11, wherein said metal member or set of members comprises a first member that is capable of carrying a compressive load and a second member that is capable of carrying a tensile load.

18. The prosthesis of claim 11, wherein said sufficiently large externally applied load comprises compression.

19. The prosthesis of claim 11, wherein said sufficiently large externally applied load comprises flexion.

20. A spinal disc prosthesis comprising:

a first endplate and a second endplate each suitable to attach to respective vertebrae;

a first member interposed between and adhered to said first and second endplates; and

a second member which, under at least some conditions, is capable of transferring a tensile load between a first connection point on said first endplate and a second connection point on said second endplate.

21. The prosthesis of claim 20, wherein said second member comprises a metal.

22. The prosthesis of claim 20, wherein said second member is elongated.

23. The prosthesis of claim 20, wherein said second member is pivotable with respect to at least one of said endplates.

24. The prosthesis of claim 20, wherein said second member is pivotable with respect to both of said endplates.

25. The prosthesis of claim 20, wherein said second member comprises a ball or portion thereof suitable to be part of a ball-and-socket joint.

26. The prosthesis of claim 20, wherein said second member comprises two balls or portions thereof each suitable to be part of respective ball-and-socket joints, one of said balls or portions thereof being at each end of said first member.

27. The prosthesis of claim 26, wherein each of said balls or portions thereof has a respective convex curved surface, and said convex curved surfaces face each other.

28. The prosthesis of claim 20, wherein said second member comprises an elongated central portion having at each end a ball or portion thereof, and wherein each of said endplates further comprises a corresponding socket for each of said balls or portions thereof.

29. The prosthesis of claim 20, wherein said first member transfers said tensile load only for separation distances between said first connection point and said second connection point that are greater than a certain separation distance.

30. The prosthesis of claim 20, wherein said first member is disposed to be incapable of carrying any load component other than said tensile load.

31. The prosthesis of claim 20, further comprising a second member that is capable, under at least some conditions, of transferring a compressive load between said first endplate and said second endplate.

32. A spinal disc prosthesis comprising:

a first endplate and a second endplate each suitable to attach to respective vertebrae;

at least two first members which, under at least some conditions, are capable of transferring a tensile load between a first connection point on said first endplate and a second connection point on said second endplate.

33. The prosthesis of claim 32, wherein said two first members are substantially identical to each other.

34. The prosthesis of claim 32, wherein said two first members are symmetrically located around an anterior-posterior centerline of said prosthesis.

35. The prosthesis of claim 32, further comprising a polymeric member interposed between and adhered to said first and second endplates.