Polyaxial adjustment of facet joint prostheses

• US 20050131406A1
• Filed: 12/15/2003
• Published: 06/16/2005
• Est. Priority Date: 12/15/2003
• Status: Abandoned Application

• Current Assignee: Facet Solutions, Inc. (Globus Medical, Inc.)
• Original Assignee: Archus Orthopedics, Inc. (Globus Medical, Inc.)
• Inventors: Reiley, Mark A., Scribner, Robert M., Stinson, David T., Tokish, Leonard J. Jr.
• Application Number:
  US10/737,705
• Publication Number:
  US 20050131406A1
• Time in Patent Office: Days
• US Class Current: 606/247
• CPC Class Codes: A61B 17/7064 Devices acting on, attached to, or simulating the effect of, vertebral facets; Tools therefor
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61F 2/4405 for apophyseal or facet joints, i.e. between adjacent spinous or transverse processes devices implanted between spinous or transverse processes A61B17/7062
• CPC Class Codes: A61F 2/4637 for connecting or disconnecting two parts of a prosthesis
• CPC Class Codes: A61F 2002/30365 with additional means for limiting said rotation
• CPC Class Codes: A61F 2002/30367 with additional means for preventing said rotation
• CPC Class Codes: A61F 2002/30373 with additional means for preventing said translation
• CPC Class Codes: A61F 2002/30375 with an intermediate bushing or sleeve between the moving parts
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30507 using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30538 for adjusting angular orientation
• CPC Class Codes: A61F 2002/3055 for adjusting length
• CPC Class Codes: A61F 2002/30553 for adjusting a position by translation along an axis
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30649 Ball-and-socket joints
• CPC Class Codes: A61F 2002/448 comprising multiple adjacent spinal implants within the same intervertebral space or within the same vertebra, e.g. comprising two adjacent spinal implants
• CPC Class Codes: A61F 2002/4631 the prosthesis being specially adapted for being cemented
• 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 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2250/0006 : for adjusting angular orientation
• CPC Class Codes: A61F 2250/0007 : for adjusting length
• CPC Class Codes: A61F 2250/0008 : for adjusting a position by translation along an axis or two perpendicular axes
• 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
• CPC Class Codes: A61F 2310/00047 : Aluminium or Al-based alloys
• CPC Class Codes: A61F 2310/00131 : Tantalum or Ta-based alloys
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures

Abstract

Prostheses, systems, and methods are provided for replacement of natural facet joints between adjacent vertebrae using polyaxial attachment mechanisms for securing the prostheses to the vertebrae. A cephalad prosthesis attached to a superior adjacent vertebra replaces the inferior half of a natural facet joint. A caudal prosthesis attached to an inferior adjacent vertebra replaces the superior half of a natural facet joint. Both the cephalad and caudal prostheses are configured with artificial facet joint structures that include articulating surfaces that cooperate and form an artificial articular configuration. The polyaxial attachment mechanism permits adjustment of the position of the artificial facet joint structure along more than one axis at or after the time the cephalad or caudal prosthesis is attached to a vertebra.

Claims

1. A facet joint prosthesis comprising an artificial facet joint element connected to a fixation element by a polyaxially adjustable connection.

2. The facet joint prosthesis of claim 1 wherein the polyaxially adjustable connection is adapted and configured to permit the artificial facet joint element to be rotated with respect to the fixation element around more than one axis.

3. The facet joint prosthesis of claim 2 wherein the polyaxially adjustable connection is further adapted and configured to permit the position of the artificial facet joint element to be continuously adjustable within an adjustability range with respect to the fixation element.

4. The facet joint prosthesis of claim 2 wherein the polyaxially adjustable connection comprises a limit stop.

5. The facet joint prosthesis of claim 1 wherein the artificial facet joint element is adapted to be movable medially with respect to the fixation element.

6. The facet joint prosthesis of claim 1 wherein the artificial facet joint lement is adapted to be movable laterally with respect to the fixation element.

7. The facet joint prosthesis of claim 1 wherein the artificial facet joint element is adapted to be movable superiorly with respect to the fixation element.

8. The facet joint prosthesis of claim 1 wherein the artificial facet joint element is adapted to be movable inferiorly with respect to the fixation element.

9. The facet joint prosthesis of claim 1 wherein the polyaxially adjustable connection is adapted and configured to permit the artificial facet joint element to be moved with respect to the fixation element after installation of the facet joint prosthesis in a patient.

10. The facet joint prosthesis of claim 1 further comprising a fastener adapted and configured to prevent movement between the artificial facet joint element and the fixation element.

11. The facet joint prosthesis of claim 1 wherein the artificial facet joint element comprises a cephalad facet joint bearing surface and a cephalad facet joint bearing surface support.

12. The facet joint prosthesis of claim 11 wherein the cephalad facet joint bearing surface and the cephalad facet joint bearing surface support are adapted and configured to be disposed laterally from a midline of a vertebra when the facet joint prosthesis is installed in a patient.

13. The facet joint prosthesis of claim 11 wherein the cephalad facet joint bearing surface and the cephalad facet joint bearing surface support are adapted and configured to be disposed approximately at a midline of a vertebra when the facet joint prosthesis is installed in a patient.

14. The facet joint prosthesis of claim 1 wherein the artificial facet joint element comprises a caudal facet joint bearing surface and a caudal facet joint bearing surface support.

15. The facet joint prosthesis of claim 14 wherein the caudal facet joint bearing surface and the caudal facet joint bearing surface support are adapted and configured to be disposed laterally from a midline of a vertebra when the facet joint prosthesis is installed in a patient.

16. The facet joint prosthesis of claim 1 further comprising a longitudinally adjustable connection between the artificial facet joint element and the fixation element.

17. The facet joint prosthesis of claim 16 wherein the artificial facet joint element comprises a facet joint bearing surface and a facet joint bearing surface support, the facet joint bearing surface support being adapted and configured to be longitudinally movable with respect to the fixation element.

18. The facet joint prosthesis of claim 17 further comprising a fastener adapted and configured to prevent relative movement between the facet joint bearing surface support and the fixation element.

19. The facet joint prosthesis of claim 17 wherein the facet joint bearing surface support is further adapted and configured to be rotatable about a support longitudinal axis.

20. The facet joint prosthesis of claim 1 wherein the polyaxially adjustable connection comprises a facet joint element connection surface and a fixation element connection surface, the facet joint element connection surface and fixation element connection surface being adapted and configured to be movable with respect to each other.

21. The facet joint prosthesis of claim 1 wherein the polyaxially adjustable connection comprises a base member attached to the artificial facet joint element and movable with respect to the fixation element.

22. The facet joint prosthesis of claim 21 wherein the base member is further adapted and configured to be movable with respect to the artificial facet joint element.

23. A facet joint prosthesis comprising:

first and second artificial facet joint elements;

a fixation element; and

a polyaxially adjustable connection between at least one of the first or second facet joint elements and the fixation element.

24. The facet joint prosthesis of claim 23 wherein the first artificial facet joint element comprises an artificial cephalad facet joint element and the second artificial facet joint element comprises an artificial caudal facet joint element.

25. The facet joint prosthesis of claim 24 wherein the fixation element comprises a cephalad fixation element and the polyaxially adjustable connection comprises a cephalad polyaxially adjustable connection, the facet joint prosthesis further comprising a caudal fixation element and a caudal polyaxially adjustable connection between the artificial caudal facet joint bearing element and the caudal fixation element.

26. The facet joint prosthesis of claim 25 wherein the artificial cephalad facet joint element comprises a cephalad bearing surface and a cephalad bearing surface support.

27. The facet joint prosthesis of claim 25 wherein the artificial caudal facet joint element comprises a caudal bearing surface and a caudal bearing surface support.

28. The facet joint prosthesis of claim 23 wherein the first and second artificial facet joint elements comprise first and second artificial cephalad facet joint elements, respectively.

29. The facet joint prosthesis of claim 28 wherein the fixation element comprises a first cephalad fixation element and the polyaxially adjustable connection comprises a first cephalad polyaxially adjustable connection, the facet joint prosthesis further comprising a second cephalad fixation element and a second cephalad polyaxially adjustable connection between the second artificial cephalad facet joint element and the second cephalad fixation element.

30. The facet joint prosthesis of claim 28 wherein the first and second artificial cephalad facet joint elements comprise first and second cephalad bearing surfaces, respectively.

31. The facet joint prosthesis of claim 28 wherein the first and second artificial facet joint elements comprise first and second support arms, respectively, and at least one cephalad bearing surface supported by at least one of the first and second support arms.

32. The facet joint prosthesis of claim 31 wherein the cephalad bearing surface is disposed approximately at a midline of a vertebra when the prosthesis is installed in a patient.

33. The facet joint prosthesis of claim 32 wherein the cephalad bearing surface is adapted to rotate about the support arm or arms by which it is supported.

34. The facet joint prosthesis of claim 32 further comprising an artificial caudal facet joint element comprising a caudal bearing surface adapted and configured to mate with the cephalad bearing surface.

35. The facet joint prosthesis of claim 34 wherein the polyaxially adjustable connection is adapted and configured to permit at least one of the artificial facet joint elements to be rotated with respect to the fixation element around more than one axis.

36. The facet joint prosthesis of claim 35 wherein the polyaxially adjustable connection is further adapted and configured to permit the position of at least one of the artificial facet joint elements to be continuously adjustable within an adjustability range with respect to the fixation element.

37. The facet joint prosthesis of claim 35 wherein the polyaxially adjustable connection comprises a limit stop.

38. The facet joint prosthesis of claim 23 wherein the polyaxially adjustable connection is adapted and configured to permit at least one of the artificial facet joint elements to be moved with respect to the fixation element after installation of the facet joint prosthesis in a patient.

39. The facet joint prosthesis of claim 23 further comprising a fastener adapted and configured to prevent relative movement between at least one of the artificial facet joint elements and the fixation element.

40. The facet joint prosthesis of claim 23 further comprising a longitudinally adjustable connection between at least one of the artificial facet joint elements and the fixation element.

41. The facet joint prosthesis of claim 40 wherein at least one of the artificial facet joint elements comprises a facet joint bearing surface and a facet joint bearing surface support, the facet joint bearing surface support being adapted and configured to be longitudinally movable with respect to the fixation element.

42. The facet joint prosthesis of claim 41 further comprising a fastener adapted and configured to prevent relative movement between the facet joint bearing surface support and the fixation element.

43. The facet joint prosthesis of claim 41 wherein the facet joint bearing surface support is further adapted and configured to be rotatable about a support longitudinal axis.

44. The facet joint prosthesis of claim 23 wherein the polyaxially adjustable connection comprises a facet joint element connection surface and a fixation element connection surface, the facet joint element connection surface and fixation element connection surface being adapted and configured to be movable with respect to each other.

45. The facet joint prosthesis of claim 23 wherein the polyaxially adjustable connection comprises a base member attached to at least one of the artificial facet joint elements and movable with respect to the fixation element.

46. The facet joint prosthesis of claim 45 wherein the base member is further adapted and configured to be movable with respect to at least one of the artificial facet joint elements.

47. A facet joint prosthesis comprising:

first and second fixation elements;

an artificial facet joint bearing surface adapted and configured to be disposed approximately at a midline of a vertebra when the facet joint prosthesis is installed in a patient; and

first and second polyaxially adjustable connections between the facet joint bearing surface and the first and second fixation elements, respectively.

48. The facet joint prosthesis of claim 47 wherein the first and second polyaxially adjustable connections are each adapted and configured to permit the first and second fixation elements to be rotated with respect to the artificial facet joint bearing surface around more than one axis.

49. The facet joint prosthesis of claim 47 further comprising first and second fasteners adapted and configured to prevent relative movement between the artificial facet joint bearing surface and the first and second fixation elements, respectively.

50. The facet joint prosthesis of claim 47 further comprising first and second longitudinally adjustable connections between the artificial facet joint bearing surface and the first and second fixation elements, respectively.

51. The facet joint prosthesis of claim 50 further comprising a first support arm disposed between the first fixation element and the artificial facet joint bearing surface and a second support arm disposed between the second fixation element and the artificial facet joint bearing surface, the first and second support arms each being adapted and configured to support the artificial facet joint bearing surface and to be longitudinally movable with respect to the first and second fixation elements, respectively.

52. The facet joint prosthesis of claim 51 further comprising first and second fasteners each adapted and configured to prevent relative movement between the facet joint bearing surface support and the fixation element.

53. The facet joint prosthesis of claim 51 wherein the first support arm is further adapted and configured to be rotatable about a first support arm longitudinal axis and the second support arm is further adapted and configured to be rotatable about a second support arm longitudinal axis.

54. The facet joint prosthesis of claim 51 wherein the first and second support arms comprise two separate pieces.

55. The facet joint prosthesis of claim 51 wherein the first and second support arms comprise one integral piece.

56. The facet joint prosthesis of claim 47 wherein the artificial facet joint bearing surface is adapted and configured to be a cephalad facet joint bearing surface.

57. The facet joint prosthesis of claim 47 further comprising third and fourth polyaxially adjustable connections between the facet joint bearing surface and the first and second fixation elements, respectively.

58. A facet joint prosthesis comprising:

an artificial facet joint bearing surface supported by first and second support arms adapted and configured to dispose the artificial facet joint bearing surface approximately at a midline of a vertebra when the facet joint prosthesis is installed in a patient; and

first and second fixation elements adapted and configured to attach the first and second support arms, respectively, to a vertebra.

59. The facet joint prosthesis of claim 58 wherein the first and second support arms and the artificial facet joint bearing surface comprise one integral piece.

60. The facet joint prosthesis of claim 58 further comprising first and second polyaxially adjustable connections between the first and second arms and the first and second fixation elements, respectively.

61. The facet joint prosthesis of claim 60 further comprising third and fourth polyaxially adjustable connections between the facet joint bearing surface and the first and second fixation elements, respectively.

62. A method of installing an artificial facet joint prosthesis, the prosthesis comprising a facet joint element and a fixation element, the method comprising:

attaching the prosthesis to a vertebra with the fixation element; and

adjusting positions of the facet joint element and the fixation element to a relative orientation.

63. The method of claim 62 wherein the adjusting step comprises moving the facet joint element medially with respect to the fixation element.

64. The method of claim 62 wherein the adjusting step comprises moving the facet joint element laterally with respect to the fixation element.

65. The method of claim 62 wherein the adjusting step comprises moving the facet joint element superiorly with respect to the fixation element.

66. The method of claim 62 wherein the adjusting step comprises moving the facet joint element inferiorly with respect to the fixation element.

67. The method of claim 62 wherein the attaching step is performed prior to the adjusting step.

68. The method of claim 62 wherein the attaching step is performed after the adjusting step.

69. The method of claim 62 wherein the adjusting step comprises rotating the facet joint element with respect to the fixation element around more than one axis.

70. The method of claim 69 further comprising preventing further rotation of the facet joint element after the rotating step.

71. The method of claim 62 wherein the facet joint element comprises a facet joint bearing surface, the adjusting step comprising positioning the facet joint bearing surface laterally from a vertebra midline.

72. The method of claim 62 wherein the facet joint element comprises a facet joint bearing surface, the adjusting step comprising positioning the facet joint bearing surface approximately at a vertebra midline.

73. The method of claim 62 wherein the facet joint element comprises a facet joint bearing surface, the adjusting step comprising positioning the facet joint bearing surface to face caudad.

74. The method of claim 62 wherein the facet joint element comprises a facet joint bearing surface, the adjusting step comprising positioning the facet joint bearing surface to face cephalad.

75. The method of claim 62 wherein the adjusting step comprises moving the facet joint element longitudinally with respect to the fixation element.

76. The method of claim 75 further comprising preventing further longitudinal movement of the facet joint element after the moving step.

77. The method of claim 75 wherein the adjusting step further comprises rotating the facet joint element about a facet joint element longitudinal axis.