Intervertebral disc

• US 20030233146A1
• Filed: 06/18/2002
• Published: 12/18/2003
• Est. Priority Date: 06/18/2002
• Status: Active Grant

• Current Assignee: Depuy Acromed Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Acromed Incorporated (Johnson & Johnson)
• Inventors: Grace, Melissa, Moumene, Missoum, Sorrenti, Michael D., Grinberg, Alexander, Dooris, Andrew
• Granted Patent: US 6,770,095 B2
• Time in Patent Office: Days
• US Class Current: 623/17.14
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/4425 made of articulated components
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30113 circular
• CPC Class Codes: A61F 2002/30125 elliptical or oval
• CPC Class Codes: A61F 2002/30133 kidney-shaped or bean-shaped
• CPC Class Codes: A61F 2002/30153 rectangular
• CPC Class Codes: A61F 2002/30154 square
• CPC Class Codes: A61F 2002/30158 trapezoidal
• CPC Class Codes: A61F 2002/30187 D-shaped or half-disc-shaped
• CPC Class Codes: A61F 2002/30299 umbrella-shaped or mushroom-shaped
• CPC Class Codes: A61F 2002/30331 made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2002/30364 Rotation about the common longitudinal axis
• CPC Class Codes: A61F 2002/30369 Limited lateral translation of the protrusion within a larger recess
• CPC Class Codes: A61F 2002/30372 with additional means for limiting said translation
• CPC Class Codes: A61F 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30462 retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2002/305 Snap connection
• CPC Class Codes: A61F 2002/30528 Means for limiting said movement
• 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 2002/30578 : having apertures, e.g. for receiving fixation screws
• CPC Class Codes: A61F 2002/30649 : Ball-and-socket joints
• CPC Class Codes: A61F 2002/30662 : with rotation-limiting means
• CPC Class Codes: A61F 2002/30843 : Pyramidally-shaped
• CPC Class Codes: A61F 2002/443 : having two transversal endplates and at least one intermediate component
• CPC Class Codes: A61F 2210/0014 : using shape memory or superelastic materials, e.g. nitinol
• 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 2230/0006 : circular
• CPC Class Codes: A61F 2230/0008 : elliptical or oval
• CPC Class Codes: A61F 2230/0015 : Kidney-shaped, e.g. bean-shaped
• CPC Class Codes: A61F 2230/0019 : rectangular
• CPC Class Codes: A61F 2230/0021 : square
• CPC Class Codes: A61F 2230/0026 : trapezoidal
• CPC Class Codes: A61F 2230/0034 : D-shaped
• CPC Class Codes: A61F 2230/0093 : Umbrella-shaped, e.g. mushroom-shaped
• CPC Class Codes: A61F 2310/00029 : Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/0058 : Coating made of diamond or of diamond-like carbon DLC
• CPC Class Codes: A61F 2310/0088 : Coating made of titanium nitride

Abstract

This invention relates to an intervertebral motion disc having an articulation interface and a locking interface.

Claims

1. A motion disc comprising:

a) a first prosthetic vertebral endplate having

i) an outer surface adapted to mate with a first vertebral body,

ii) an inner surface comprising a first articulation surface, and

iii) a locking surface, and

b) a second prosthetic vertebral endplate having

i) an outer surface adapted to mate with a second vertebral body,

ii) an inner surface comprising a second articulation surface, and

iii) a locking surface,

wherein the first and second articulation surfaces are adapted to form an articulating interface, and

wherein the first and second locking surfaces are adapted to form a locking interface.

2. The disc of claim 1 wherein the inner surface of the first prosthetic vertebral endplate has a projection extending therefrom, and the locking surface of the first prosthetic vertebral endplate is formed on the projection.

3. The disc of claim 2 wherein the projection extends from the first articulation surface.

4. The disc of claim 2 wherein the inner surface of the first prosthetic vertebral endplate further comprises a non-articulating surface, and the projection extends from the non-articulating surface.

5. The disc of claim 4 wherein the non-articulating surface is disposed upon the inner surface peripherally to the articulating surface.

6. The disc of claim 2 wherein the projection comprises a shank having a diameter and an enlarged end portion having a diameter, and the diameter of the enlarged end portion is greater than the diameter of the shank.

7. The disc of claim 6 wherein the articulation surface of the first prosthetic vertebral endplate is formed on the enlarged end portion of the projection.

8. The disc of claim 7 wherein the articulation surface forms an arc of between 5 degrees and 15 degrees.

9. The disc of claim 1 further comprising a sidewall disposed between the inner and outer surfaces of the first prosthetic vertebral endplate, and wherein the sidewall of the first prosthetic vertebral endplate has a projection extending therefrom, and the locking surface of the first prosthetic vertebral endplate is formed on the projection.

10. The disc of claim 2 wherein the first prosthetic vertebral endplate is an upper prosthetic vertebral endplate, and the second prosthetic vertebral endplate is a lower prosthetic vertebral endplate.

11. The disc of claim 10 wherein the first articulation surface is convex.

12. The disc of claim 10 wherein the first articulation surface is concave.

13. The disc of claim 2 wherein the first prosthetic vertebral endplate is a lower prosthetic vertebral endplate, and the second prosthetic vertebral endplate is an upper prosthetic vertebral endplate.

14. The disc of claim 13 wherein the first articulation surface is convex.

15. The disc of claim 13 wherein the first articulation surface is concave.

16. The disc of claim 1 further comprising a body portion between the inner and outer surfaces of the first prosthetic vertebral endplate, wherein the inner surface of the second prosthetic vertebral endplate has a recess extending therefrom into the body portion, and the locking surface of the second prosthetic vertebral endplate is formed in the recess.

17. The disc of claim 16 wherein the recess extends from the second articulation surface.

18. The disc of claim 16 wherein the inner surface of the second prosthetic vertebral endplate further comprises a non-articulating surface, and the recess extends from the non-articulating surface.

19. The disc of claim 18 wherein the non-articulating surface is disposed upon the inner surface peripherally to the articulating surface.

20. The disc of claim 16 wherein the recess comprises a shallow portion having a diameter and a deep portion having a diameter, and the diameter of the deep portion is greater than the diameter of the shallow portion.

21. The disc of claim 20 wherein the articulation surface of the second prosthetic vertebral endplate is formed on the deep portion of the recess.

22. The disc of claim 21 wherein the articulation surface of the second prosthetic vertebral endplate forms an arc of between 5 degrees and 15 degrees.

23. The disc of claim 16 further comprising a sidewall disposed between the inner and outer surfaces of the second prosthetic vertebral endplate, and wherein the sidewall of the second prosthetic vertebral endplate has a recess extending therefrom into the body portion, and the locking surface of the second prosthetic vertebral endplate is formed in the recess.

24. The disc of claim 1 further comprising a body portion between the inner and outer surfaces of the second prosthetic vertebral endplate,

wherein the inner surface of the second prosthetic vertebral endplate has a recess extending therefrom into the body portion, and the locking surface of the second prosthetic vertebral endplate is formed in the recess, and

wherein the inner surface of the first prosthetic vertebral endplate has a projection extending therefrom, and the locking surface of the first prosthetic vertebral endplate is formed on the projection.

25. The disc of claim 24 wherein the projection comprises a shank having a diameter and an enlarged end portion having a diameter, and the diameter of the enlarged end portion is greater than the diameter of the shank, and the recess comprises a shallow portion having a diameter and a deep portion having a diameter, and the diameter of the deep portion is greater than the diameter of the shallow portion.

26. The disc of claim 25 wherein the diameter of the enlarged end portion of the projection is between 25% and 75% of the diameter of the deep portion of the recess.

27. The disc of claim 25 wherein the diameter of the shank of the projection is between 25% and 75% of the diameter of the shallow portion of the recess.

28. The disc of claim 25 wherein the diameter of the deep portion of the recess is between 1.1 and 3 times greater than the diameter of the shallow portion of the recess.

29. The disc of claim 25 wherein the diameter of the shank of the projection is 25% to 99% of the diameter of the enlarged end portion of the projection.

30. The disc of claim 24 wherein the projection is integrally connected to the first prosthetic vertebral endplate.

31. The disc of claim 24 wherein the projection extends from the first articulation surface, and wherein the inner surface of the first prosthetic vertebral endplate has a surface area, and the first articulation surface comprises at least 80% of the surface area of a footprint of the first prosthetic vertebral endplate.

32. The disc of claim 24 wherein the enlarged end portion of the projection forms a rectangular shape.

33. The disc of claim 24 wherein the enlarged end portion of the projection comprises a threaded portion.

34. The disc of claim 24 wherein the enlarged end portion of the projection forms an anchor.

35. The disc of claim 24 wherein the enlarged end portion of the projection comprises a flexible tab.

36. The disc of claim 24 wherein the enlarged end portion of the projection comprises a memory metal.

37. The disc of claim 1 further comprising a first sidewall disposed between the inner and outer surfaces of the first prosthetic vertebral endplate, and wherein the first sidewall of the first prosthetic vertebral endplate has a first projection extending therefrom, and the locking surface of the first prosthetic vertebral endplate is formed on the first projection, and

a second sidewall disposed between the inner and outer surfaces of the second prosthetic vertebral endplate, and wherein the second sidewall of the second prosthetic vertebral endplate has a projection extending therefrom, and the locking surface of the second prosthetic vertebral endplate is formed on the second projection.

38. The disc of claim 1 wherein the locking surface of the first prosthetic vertebral endplate faces a first direction, and the articulation surface of the first prosthetic vertebral endplate faces in a second direction, and the first direction is substantially opposite the second direction.

39. The disc of claim 1 wherein the first prosthetic vertebral endplate further comprises a tab extending therefrom and forming a vertically-disposed distal portion forming a pair of tongues, each tongue having a hole therethrough for reception of a fastener, wherein the tongues form a nest therebetween.

40. The disc of claim 1 wherein the outer surface of the first prosthetic vertebral endplate comprises at least one projection extending therefrom and having a pyramid shape.

41. A motion disc comprising:

a) a first prosthetic vertebral endplate having

i) an outer surface adapted to mate with a first vertebral body,

ii) an inner surface comprising a first articulation surface, and

b) a second prosthetic vertebral endplate having

i) an outer surface adapted to mate with a second vertebral body,

ii) an inner surface comprising a second articulation surface, and

c) locking means for limiting the extent of disengagement of the first articulation surface from the second articulation surface.

42. The disc of claim 41 further comprising a first body portion between the inner and outer surfaces of the first prosthetic vertebral endplate, and a second body portion between the inner and outer surfaces of the second prosthetic vertebral endplate,

wherein the locking means comprises:

a projection extending from the inner surface of the first prosthetic vertebral endplate, and

a recess extending from the inner surface of the second prosthetic vertebral endplate.

43. The disc of claim 41 wherein the locking means comprises a component selected from the group consisting of a ligament, a cable, and a spring.

44. The disc of claim 43 wherein the locking means comprises a ligament.

45. The disc of claim 43 wherein each prosthetic vertebral endplate further comprises a sidewall disposed between its inner and outer surfaces, and the component is attached to each sidewall.

46. The disc of claim 41 wherein the outer surface of the first prosthetic vertebral endplate has a convex shape.

47. The disc of claim 41 wherein the outer surfaces of the prosthetic vertebral endplates define a lordotic angle.

48. The disc of claim 41 wherein the lordotic angle is between 5 and 10 degrees.

49. The disc of claim 48 wherein the lordotic angle is between 6 and 8 degrees.

50. The disc of claim 41 further comprising a first body portion between the inner and outer surfaces of the first prosthetic vertebral endplate, and a second body portion between the inner and outer surfaces of the second prosthetic vertebral endplate,

wherein the locking means comprises:

a projection extending from the inner surface of the first prosthetic vertebral endplate, and

a recess extending from the inner surface of the second,

wherein the projection has an enlarged end portion having a D-shaped surface, and the recess has a shallow portion having a D-shape.

51. A motion disc comprising:

a) an upper prosthetic vertebral endplate having a first surface and an second surface,

b) a lower prosthetic vertebral endplate having a first surface and an second surface,

c) means for restraining pivotal movement of the upper prosthetic vertebral endplate to the lower prosthetic vertebral endplate,

wherein at least a portion of the second surface of the upper prosthetic vertebral endplate and at least a portion of the first surface of the lower prosthetic vertebral endplate form a conforming articulating interface, and

wherein the means for restraining pivotal movement is encompassed by the articulating surface.

52. The disc of claim 51 further comprising a body portion between the inner and outer surfaces of the second prosthetic vertebral endplate,

wherein the inner surface of the second prosthetic vertebral endplate has a recess extending therefrom into the body portion, and the locking surface of the second prosthetic vertebral endplate is formed in the recess,

wherein the inner surface of the first prosthetic vertebral endplate has a projection extending therefrom, and the locking surface of the first prosthetic vertebral endplate is formed on the projection,

wherein the projection comprises a shank having a diameter and an enlarged end portion having a diameter, and the diameter of the enlarged end portion is greater than the diameter of the shank, and the recess comprises a shallow portion having a diameter and a deep portion having a diameter, and the diameter of the deep portion is greater than the diameter of the shallow portion.

53. The disc of claim 52 wherein means for restraining pivotal movement is defined by the diameter of the shank of the projection and the diameter of the shallow portion of the recess.

54. The disc of claim 52 wherein means for restraining pivotal movement is defined by the diameter of the enlarged end portion of the projection and the diameter of the deep portion of the recess.

55. The disc of claim 51 wherein the means for restraining pivotal movement limits the anterior-posterior motion of the device to between 1 and 30 degrees.

56. The disc of claim 55 wherein the means for restraining pivotal movement limits the anterior-posterior motion of the device to between 10 and 15 degrees.

57. The disc of claim 56 wherein the means for restraining pivotal movement limits the anterior-posterior motion of the device to about 13 degrees.

58. The disc of claim 51 wherein the means for restraining pivotal movement limits the lateral motion of the device to between 1 and 30 degrees.

59. The disc of claim 58 wherein the means for restraining pivotal movement limits the lateral motion of the device to between 5 and 10 degrees.

60. The disc of claim 59 wherein the lower prosthetic vertebral endplate comprises a recess extending from the first surface of the lower prosthetic vertebral endplate, and the means for restraining pivotal movement comprises a shock-absorbing material disposed within the recess.

61. A prosthetic vertebral endplate for use in a motion disc, the prosthetic vertebral endplate comprising:

i) an outer surface adapted to mate with a vertebral body,

ii) an inner surface comprising an articulation surface, and

iii) a locking surface.

62. The prosthetic vertebral endplate of claim 61 wherein the articulation surface comprises a curved bearing surface.

63. The prosthetic vertebral endplate of claim 61 wherein the curved bearing surface comprises a hemispherical portion.

64. The prosthetic vertebral endplate of claim 61 wherein the articulation surface provides pivotal and axial motion.

65. The prosthetic vertebral endplate of claim 61 wherein the articulation surface further provides translational motion.

66. The prosthetic vertebral endplate of claim 61 wherein the inner surface of the first prosthetic vertebral endplate has a surface area, and the first articulation surface comprises at least 80% of a footprint of the first prosthetic vertebral endplate.

67. The prosthetic vertebral endplate of claim 61 wherein the articulation surface is formed on the inner surface.

68. The prosthetic vertebral endplate of claim 61 wherein the articulation surface is formed in the body of the prosthetic vertebral endplate.

69. The prosthetic vertebral endplate of claim 61 wherein at least a portion of the articulation surface has a surface roughness Ra of no more than 10 nm.

70. The prosthetic vertebral endplate of claim 61 wherein the articulation surface has a convex shape.

71. A vertebral motion disc comprising:

a) an first prosthetic vertebral endplate having an outer surface adapted to mate with a first vertebra, and inner surface having a projection extending therefrom,

b) a second prosthetic vertebral endplate having a outer surface adapted to mate with a second vertebra, an inner surface, a body portion between the inner and outer surfaces, and a recess extending from the inner surface into the body portion,

wherein at least a portion of the inner surface of the first prosthetic vertebral endplate and at least a portion of the inner surface of the second prosthetic vertebral endplate form a conforming articulating interface.

72. A vertebral motion disc comprising:

a) a first prosthetic vertebral endplate having an outer surface adapted to mate with a first vertebra, and inner surface having a projection extending therefrom,

b) a second prosthetic vertebral endplate having a outer surface adapted to mate with a second vertebra, an inner surface, a body portion between the inner and outer surfaces, and a recess extending from the inner surface into the body portion,

wherein at least a portion of the inner surface of the first prosthetic vertebral endplate and at least a portion of the inner surface of the second prosthetic vertebral endplate form an articulating interface, and

wherein the recess has a shallow portion having a width and a deep portion having a width, wherein the width of the deep portion is greater than the width of the shallow portion.

73. A vertebral motion disc comprising:

a) an first prosthetic vertebral endplate having an outer surface adapted to mate with a first vertebra, and inner surface having a projection extending therefrom,

b) a second prosthetic vertebral endplate having a outer surface adapted to mate with a second vertebra, an inner surface, a body portion between the inner and outer surfaces, and a recess extending from the inner surface into the body portion,

wherein at least a portion of the inner surface of the first prosthetic vertebral endplate and at least a portion of the inner surface of the second prosthetic vertebral endplate form an articulating interface,

wherein the projection extends from a non-articulating portion of the inner surface.

74. A prosthetic vertebral endplate for use in a vertebral motion disc comprising:

a) an outer surface adapted to mate with a first vertebra,

b) an inner surface having a projection extending therefrom,

wherein at least a portion of the inner surface is adapted to form an articulating surface, and wherein the projection has an inner portion having a width and a outer portion having a width, wherein the width of the outer portion is greater than the width of the inner portion.

75. A prosthetic vertebral endplate for use in a vertebral motion disc comprising:

a) an outer surface adapted to mate with a second vertebra,

b) an inner surface,

c) a body portion between the inner and outer surfaces, and

d) a recess extending from the inner surface into the body portion,

wherein at least a portion of the inner surface is adapted to form an articulating surface, and,

wherein the recess has a shallow portion having a width and a deep portion having a width, wherein the width of the deep portion is greater than the width of the shallow portion.

76. A vertebral motion disc comprising:

a) an first prosthetic vertebral endplate having an outer surface adapted to mate with a first vertebra, and inner surface having a projection extending therefrom, the projection having an outer articulating surface,

b) a second prosthetic vertebral endplate having a outer surface adapted to mate with a second vertebra, an inner surface, a body portion between the inner and outer surfaces, and a recess extending from the inner surface into the body portion, the recess forming an inner articulating surface,

wherein the outer articulating surface of the projection and the inner articulating surface of the recess form a conforming articulating interface.

77. A vertebral motion disc comprising:

a) an first prosthetic vertebral endplate having an outer surface adapted to mate with a first vertebra, and inner surface having a projection extending therefrom, the projection having an outer articulating surface,

b) a second prosthetic vertebral endplate having a outer surface adapted to mate with a second vertebra, an inner surface, a body portion between the inner and outer surfaces, and a recess extending from the inner surface into the body portion, the recess forming an inner articulating surface,

wherein the recess has a shallow portion having a width and a deep portion having a width, wherein the width of the deep portion is greater than the width of the shallow portion.

78. A prosthetic vertebral endplate for use in a vertebral motion disc comprising:

a) an outer surface adapted to mate with a first vertebra,

b) an inner surface having a projection extending therefrom, the projection forming an outer face,

wherein at least a portion of the outer surface of the projection is adapted to form an articulating surface, and

wherein the projection has an inner portion having a width and a outer portion having a width, wherein the width of the outer portion is greater than the width of the inner portion.

79. A prosthetic vertebral endplate for use in a vertebral motion disc comprising:

a) an outer surface adapted to mate with a second vertebra,

b) an inner surface,

c) a body portion between the inner and outer surfaces, and

d) a recess extending from the inner surface into the body portion, the recess forming an inner surface,

wherein at least a portion of the inner surface of the recess is adapted to form an articulating surface, and

wherein the recess has a shallow portion having a width and a deep portion having a width, wherein the width of the deep portion is greater than the width of the shallow portion.

80. A motion disc comprising:

a) a first prosthetic vertebral endplate having

i) an outer surface adapted to mate with a first vertebral body,

ii) an inner surface comprising a first articulation surface,

iii) a first body portion between the inner and outer surfaces of the first prosthetic vertebral endplate

wherein the inner surface of the first prosthetic vertebral endplate has a recess extending therefrom into the first body portion and forming a first locking surface and a first articulation surface, and

b) a second prosthetic vertebral endplate having

i) an outer surface adapted to mate with a second vertebral body,

ii) an inner surface comprising a second articulation surface,

iii) a second body portion between the inner and outer surfaces of the second prosthetic vertebral endplate,

wherein the inner surface of the second prosthetic vertebral endplate has a recess extending therefrom into the second body portion and forming a second locking surface and a second articulation surface, and

c) a connector comprising a shank and first and second end portions,

wherein the first end portion of the connector comprises a first locking surface and a first articulation surface, and wherein the second end portion of the connector comprises a second locking surface and a second articulation surface,

wherein the first and second articulation surfaces are adapted to form an articulating interface, and

wherein the first and second locking surfaces are adapted to form a locking interface.