Vertebral facet joint prosthesis and method of fixation

• US 20050177240A1
• Filed: 06/10/2004
• Published: 08/11/2005
• Est. Priority Date: 02/06/2004
• Status: Active Grant

• Current Assignee: Spinal Elements, Inc.
• Original Assignee: Spinal Elements, Inc.
• Inventors: Blain, Jason
• Granted Patent: US 7,846,183 B2
• Time in Patent Office: Days
• US Class Current: 623/17.150
• CPC Class Codes: A61B 17/7062 Devices acting on, attached to, or simulating the effect of, vertebral processes, vertebral facets or ribs rib fixation devices A61B17/8076; Tools for such devices
• CPC Class Codes: A61B 17/7064 Devices acting on, attached to, or simulating the effect of, vertebral facets; Tools therefor
• CPC Class Codes: A61B 17/88 Osteosynthesis instruments; Methods or means for implanting or extracting internal or external fixation devices A61B17/7074 takes precedence
• CPC Class Codes: A61B 2017/564 Methods for bone or joint treatment
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/30771 applied in original prostheses, e.g. holes or grooves
• 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 2/442 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 2/4425 made of articulated components
• CPC Class Codes: A61F 2/46 Special tools or methods for implanting or extracting artificial joints, accessories, bone grafts or substitutes, or particular adaptations therefor
• CPC Class Codes: A61F 2002/302 toroidal, e.g. rings
• CPC Class Codes: A61F 2002/30225 Flat cylinders, i.e. discs
• 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 2002/30405 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 2002/30485 plastically deformable
• CPC Class Codes: A61F 2002/30507 using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30514 using a locking washer
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30769 madreporic
• CPC Class Codes: A61F 2002/30772 : Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• 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 2230/0065 : toroidal, e.g. ring-shaped, doughnut-shaped
• CPC Class Codes: A61F 2230/0069 : cylindrical
• 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 2310/00203 : containing alumina or aluminium oxide
• CPC Class Codes: A61F 2310/00239 : containing zirconia or zirconium oxide ZrO2

Abstract

Devices and methods for altering the spacing and motion at the facet joints of the vertebral column are provided. One embodiment of the invention comprises a prosthesis with surfaces configured to articulate with the facets of the facet joint. A retaining member for anchoring the prosthesis within the facet joint is optionally included. Methods for surgically and less invasively implanting the prosthesis and securing the prosthesis to the articular processes or surrounding soft tissue are also provided.

Claims

1. A device for treating spinal disorders while preserving movement at a facet joint, the device comprising a prosthesis having a first face and a second face, wherein the first face is adapted to be secured to the adjacent articular surface of a facet, and the second surface is configured for sliding contact with an adjacent structure.

2. The device of claim 1, wherein the device:

is dimensioned to substantially fit within a joint capsule of the facet joint; and

has a thickness generally equal to the normal anatomic spacing between the two facets of the facet joint.

3. The device of claim 1, wherein the device:

has a curve adapted to match the natural shape of a facet;

has a size adapted to fit substantially within a joint capsule of the facet joint; and

has a thickness approximately equal to the normal anatomic spacing between the two facets of the facet joint.

4. The device of claim 1, wherein the device comprises at least one material selected from the group consisting of polymers, polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyethylene, fluoropolymers, hydrogels, elastomers, ceramics, zirconia, alumina, silicon nitride, metal(s), titanium, titanium alloy, cobalt chromium, stainless steel, and combinations of these materials.

5. The device of claim 1, wherein the second face of the device comprises a highly polished surface.

6. The device of claim 1, wherein the first face comprises a roughened surface.

7. The device of claim 1, wherein the first face comprises a porous surface.

8. The device of claim 1, wherein at least one face of the device is sufficiently malleable to be capable of generally conforming to the adjacent surface or structure under normal anatomical loads.

9. A device for treating spinal disorders while preserving movement at a facet joint, the device comprising a prosthesis having a first face and a second face, wherein the first face is adapted for sliding contact with a first articular process of the facet joint, and the second surface is configured for sliding contact with a second articular process of the facet joint.

10. The device of claim 9, wherein the device:

is dimensioned to substantially fit within a joint capsule of the facet joint; and

has a thickness generally equal to the normal anatomic spacing between the two facets of the facet joint.

11. The device of claim 9, wherein the device:

has a curve adapted to match the natural shape of a facet;

has a size adapted to fit substantially within a joint capsule of the facet joint; and

has a thickness approximately equal to the normal anatomic spacing between the two facets of the facet joint.

12. The device of claim 9, wherein the device has an average thickness within the range of about 0.5 mm to about 3 mm.

13. The device of claim 9, wherein the device has an average thickness within the range of about 1 mm to about 2 mm.

14. The device of claim 9, wherein the device has a diameter within the range of about 5 mm to about 25 mm.

15. The device of claim 9, wherein the device has a size within the range of about 10 to about 20 mm in diameter.

16. The device of claim 9, wherein at least one face of the device has a bone contacting surface area of about 25 mm² to about 700 mm².

17. The device of claim 9, wherein at least one face of the device has a bone contacting surfacearea of about 20 mm² to about 400 mm².

18. The device of claim 9, wherein at least one face of the device has a bone contacting surfacearea of about 20 mm² to about 100 mm².

19. The device of claim 9, wherein at least one face of the device comprises a highly polished surface.

20. The device of claim 9, wherein the prosthesis further comprises an anchoring assembly configured to generally maintain at least a portion of the prosthesis between the first articular process and the second articular process of the facet joint.

21. The device of claim 20, wherein the anchoring assembly comprises an elongate member and at least one retaining member.

22. The device of claim 21, wherein the elongate member comprises a wire or cable.

23. The device of claim 22, wherein the elongate member comprises a solid wire or cable.

24. The device of claim 22, wherein the elongate member comprises a braided cable.

25. The device of claim 22, wherein the retaining member comprises a set-screw retaining ring.

26. The device of claim 22, wherein at least one end comprises a threaded interface.

27. The device of claim 22, wherein the retaining member comprises a threaded retainer.

28. The device of claim 22, wherein the retaining member is integrally formed with one end of the elongate member.

29. The device of claim 22, wherein at least one face of the device is sufficiently malleable to be capable of generally conforming to the shape of at least a portion of an articular process under normal anatomical conditions.

30. A device for treating facet joint dysfunction, the device comprising:

a body with a first face and a second face adapted to contact the bony or cartilaginous articular surfaces of the facets of adjacent vertebrae, wherein the device has at least one retaining interface capable of accepting an elongate retainer through it;

an elongate retainer adapted for generally maintaining the location of the body with respect to the facet joint, the retainer having;

a first portion adapted to engage a first facet of the facet joint; and

a second portion adapted to engage a second facet of the facet joint.

31. The device of claim 30, wherein the device:

has a generally circular cross section;

has a diameter adapted to fit substantially within a joint capsule of the facet joint; and

has a thickness generally equal to the normal anatomic spacing between the two facets of the facet joint.

32. The device of claim 30, wherein the device:

has a curve adapted to match the natural shape of a facet;

has a size adapted to substantially fit within a joint capsule of the facet.

33. The device of claim 30, wherein the device comprises at least one material selected from the group consisting of polymers, polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyethylene, fluoropolymers, hydrogels, elastomers;

ceramics, zirconia, alumina, silicon nitride;

metal(s), titanium, titanium alloy, cobalt chromium, stainless steel; and

combinations of these materials.

34. The device of claim 30, wherein the elongate retainer comprises a braided polymer.

35. The device of claim 30, wherein the elongate retainer comprises a braided metal.

36. The device of claim 30, wherein the elongate retainer comprises a solid structure.

37. The device of claim 30, wherein the elongate retainer comprises a flexibility sufficient to tie a knot in the elongate retainer.

38. The device of claim 30, wherein the elongate retainer comprises:

at least one end with a threaded metal section adapted to accept a threaded nut; and

a threaded nut.

39. The device of claim 38, wherein threaded section is pressed or crimped onto the elongate retainer.

40. The device of claim 38, wherein the threaded section and nut comprise titanium, titanium alloy, cobalt chromium, or stainless steel.

41. The device of claim 30, comprising at least one face with a highly polished surface.

42. The device of claim 30, wherein the elongate member comprises:

at least one end with an enlarged cross sectional area.

43. The device of claim 42, wherein the elongate member comprises at least one end with a bulbous retainer.

44. The device of claim 42, wherein the elongate member comprises at least one end with a flared retainer.

45. The device of claim 42, wherein the elongate member comprises at least one end with a T-bar retainer.

46. The device of claim 42, wherein the elongate member comprises at least one end with an integral ring retainer.

47. The device of claim 42, wherein at least one face of the device is sufficiently malleable to be capable of generally conforming the shape of at least a portion of an articular surface under normal anatomical loads.

48. A prosthesis for treating facet joint dysfunction, the prosthesis comprising:

a body with a first face and a second face, at least one face adapted for sliding contact with the bony or cartilaginous articular surfaces of the facets of adjacent vertebrae, wherein the prosthesis has at least one retaining interface capable of accepting a retaining member; and

a retaining member adapted for securing the location of the body with respect to at least one of the articular surfaces.

49. The prosthesis of claim 48, wherein the retaining member comprises:

a first portion adapted to engage the retaining interface of the body; and

a second portion adapted to engage a first facet of the facet joint.

50. The prosthesis of claim 49, wherein the retaining member further comprises a third portion adapted to engage a second facet of the facet joint.

51. The prosthesis of claim 49, wherein;

the retaining member comprises a threaded shaft; and

the retaining interface of the body comprises a threaded hole with an opening on one face of the body.

52. The prosthesis of claim 48, wherein the retaining member comprises a projection extending from the body.

53. The prosthesis of claim 48, wherein the retaining member comprises:

a longitudinal member adapted to engage the retaining interface of the body; and

at least one retaining ring capable of engaging the longitudinal member.

54. The prosthesis of claim 53, wherein the retaining ring comprises a set-screw.

55. The prosthesis of claim 54, wherein the set-screw has a blunted tip.

56. The prosthesis of claim 54, wherein the set-screw has a curved tip.

57. The prosthesis of claim 54, wherein the set-screw has a piercing tip.

58. The prosthesis of claim 53, wherein at least one of the retaining rings is a friction fit retaining ring.

59. The prosthesis of claim 48, wherein the body is curved.

60. The prosthesis of claim 48, wherein the prosthesis comprises at least one material selected from the group consisting of polymers, polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyethylene, fluoropolymers, hydrogels, elastomers, ceramics, zirconia, alumina, silicon nitride;

metal(s), titanium, titanium alloy, cobalt chromium, stainless steel, and combinations of these materials.

61. The prosthesis of claim 48, wherein at least one face of the prosthesis is sufficiently malleable to be capable of generally conforming to the adjacent surface or structure.

62. A prosthesis for treating facet joint dysfunction, the prosthesis comprising:

a first body with a first face and a second face;

a second body with a first face and a second face;

wherein

the first face of each body is adapted to articulate with the first face of the other body; and

the second face of each body is adapted to engage a facet of a facet joint.

63. The prosthesis of claim 62, further comprising

a retaining member adapted for securing the location of at least one body.

64. The device of claim 62, wherein at least one face of the prosthesis is sufficiently malleable to be capable of generally conforming to the adjacent surface or structure under normal anatomical conditions.

65. A method of treating vertebral dysfunction, comprising:

opening a facet joint capsule between two facets of adjacent vertebral bodies;

distracting the adjacent vertebral bodies from a first spacing to a second spacing; and

placing a spacer between the two facets to maintain the second spacing.

66. The method of claim 65, further comprising the steps of:

securing the spacer to one facet of the facet joint.

67. The method of claim 65, further comprising the steps of:

securing the spacer in the facet joint capsule.

68. The method of claim 67, wherein the step of securing the spacer comprises:

drilling a hole through each facet;

threading a retainer through the hole of the first facet;

threading the retainer through the hole in the spacer;

threading the retainer through the hole of the second facet; and

tying a knot in at least one end of the retainer.

69. The method of claim 67, further comprising the steps of:

drilling a hole through a first facet and a second facet;

advancing a retainer through the hole of the first facet;

advancing the retainer through the hole in the spacer;

threading the retainer through the hole of the second facet; and

threadably engaging an anchor to at least one end of the retainer.

70. The method of claim 67, further wherein the step of securing the spacer comprises:

providing a spacer with a retaining member; and

advancing the retaining member at least partially into a facet to engage the facet.

71. The method of claim 65, further comprising the step of:

conforming the shape of at least a portion of the spacer to at least a portion of a facet of the facet joint.

72. The method of claim 71, wherein the conforming step is performed after the placing step.

73. The method of claim 71, wherein the conforming step is performed while the spacer is generally located between the facets of the facet joint.

74. A method of treating a facet joint, comprising the steps of:

providing a prosthesis dimensioned to fit within a facet joint capsule;

accessing a facet joint capsule between two articular processes of two vertebrae;

inserting a prosthesis generally within the joint capsule; and

maintaining the prosthesis generally between the two articular processes without penetrating the surface of a vertebrae.

75. The method of claim 74, wherein the maintaining step comprises anchoring the prosthesis to the joint capsule tissue.

76. The method of claim 74, wherein the maintaining step comprises generally closing the joint capsule over the prosthesis.

77. The method of claim 74, wherein the maintaining step comprises suturing the prosthesis to the surrounding soft tissue.

78. The method of claim 74, further comprising the step of:

conforming the shape of at least a portion of the prosthesis to at least a portion of a facet of the facet joint.

79. The method of claim 78, wherein the conforming step is performed after the inserting step.

80. The method of claim 78, wherein the conforming step is performed while the prosthesis is generally located between the facets of the facet joint.