Deflectable spacer for use as an interspinous process implant and method

• US 20030065330A1
• Filed: 08/29/2002
• Published: 04/03/2003
• Est. Priority Date: 10/20/1998
• Status: Active Grant

• Current Assignee: Kyphon SARL (Medtronic Plc)
• Original Assignee: St. Francis Medical Technologies, Inc. (Medtronic Plc)
• Inventors: Flynn, John J., Zucherman, James F., Winslow, Charles J., Hsu, Ken Y.
• Granted Patent: US 7,029,473 B2
• Time in Patent Office: Days
• US Class Current: 606/61
• CPC Class Codes: A61B 17/66 Alignment, compression or distraction mechanisms
• 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 17/7071 Implants for expanding or repairing the vertebral arch or wedged between laminae or pedicles; Tools therefor
• CPC Class Codes: A61K 31/37 Coumarins, e.g. psoralen

Abstract

The present invention is a interspinous process device with a deflectable spacer which can be placed between adjacent spinous processes to limit the movement of the vertebrae. The device limits the range of motion of the spinous processes.

Claims

1. An implant adapted to be placed between spinous processes comprising:

a body having a shaft extending therefrom;

a spacer that is rotatably mounted on the shaft;

wherein said spacer is comprised of a deflectable material.

2. The implant of claim 1 wherein said deflectable material is selected from the group consisting of:

polyetheretherketone and polyetherketoneketone.

3. The implant of claim 1 wherein said deflectable material is selected from the group consisting of:

polyetheretherketone, a polyaryletheretherketon, a polyetherketoneketone, a high molecular weight polymer, a theromplastic, and a polycarbonate urethane.

4. The implant of claim 1 wherein said spacer is comprised of:

an inner spacer that is rotatably mounted about the shaft; and

an outer spacer that is mounted on said inner spacer.

5. The implant of claim 1 wherein said spacer is comprised of:

an inner spacer that is rotatably mounted about the shaft; and

an outer spacer that is movably mounted relative to said inner spacer.

6. The implant of claim 1 wherein said spacer is comprised of:

an inner spacer that is rotatably mounted about the shaft; and

an outer spacer that is mounted on said inner spacer; and

at least one of said inner spacer and said outer spacer is comprised of one of the group consisting of polyetheretherketone and polyetherketoneketone.

7. The implant of claim 1 wherein said spacer has a shape selected from the group consisting of elliptical-shaped, cylindrical-shaped, ovoid-shaped, oval-shaped, track-shaped and rectangle-shaped with curved ends.

8. The implant of claim 5 wherein said outer spacer is slidably mounted on said inner spacer.

9. The implant of claim 1 wherein said spacer is racetrack-shaped.

10. The implant of claim 1 wherein said spacer has rounded ends and flattened upper and lower surfaces.

11. The implant of claim 4 wherein:

said inner spacer has one of a flattened or a slightly radiused upper and lower surfaces and rounded first and second end, and

said outer spacer has one of a flattened or a slightly radiused upper and lower surfaces and rounded first and second ends.

12. The implant of claim 4 wherein:

said inner spacer and said outer spacer have a cross-section shape selected from the group consisting of elliptical-shaped, cylindrical-shaped, ovoid-shaped, oval-shaped, track-shaped, football-shaped and rectangle-shaped with curved ends, and

13. The implant of claim 1 wherein:

said spacer has a dimension selected from the group consisting of 6 mm, 8 mm, 10 mm, 12 mm, and 14 mm.

14. The implant of claim 4 wherein the inner spacer and the outer spacer is selected from the group consisting of polyetheretherketone and polyetherketoneketone.

15. The implant of claim 4 wherein:

the inner spacer is football-shaped in cross-section; and

the outer spacer has a cross-section selected from the group consisting of elliptical-shaped, cylindrical-shaped, ovoid-shaped, oval-shaped, track-shaped, and rectangle-shaped with curved ends.

22. The implant of claim 4 wherein:

said inner spacer has upper and lower outer surfaces; and

said outer spacer has upper and lower inner surfaces; and

wherein said inner surface of said outer spacer are spaced from the outer surfaces of said inner spacers.

43. The spacer of claim 1 wherein:

said spacer has an off-center bore that receives said shaft so that said spacer can rotate about said shaft.

45. The implant of claim 1 wherein the spacer has a dimension selected from about 6 mm to about 14 mm.

48. The implant of claim 4 wherein at least one of said inner spacer and said outer spacer is comprised of a polymer.

49. The implant of claim 4 wherein at least one of said inner spacer and said outer spacer is comprised of a thermoplastic.

50. The implant of claim 4 wherein at least one of said inner spacer and said outer spacer is comprised of a polyketone.

51. The implant of claim 4 wherein at least one of said inner spacer and said outer spacer is selected from the group consisting of polyetheretherketone, and polyetherketoneketone.

52. The implant of claim 4 wherein at least one of said inner spacer and said outer spacer is comprised of a polycarbonate urethane.

53. The implant of claim 4 wherein at least one of said inner spacer and said outer spacer is comprised of a urethane.

77. The implant of claim 1 wherein the spacer is radio-translucent.

78. The implant of claim 1 wherein the spacer is transparent to x-rays.

85. The implant of claim 1 wherein the deflectable material is selected from the group consisting of:

polyetherketone, polyetherketoneetherketoneketone, polyaryletheretherketone, and polyetheretherketoneketone, and titanium.

16. An implant adapted to be placed between spinous processes comprising:

a body having a shaft extending therefrom;

a spacer that is rotatably mounted on the shaft; and

wherein said spacer is comprised of;

an inner spacer that is rotatably mounted about the shaft; and

an outer spacer that is mounted on said inner spacer.

17. The implant of claim 16 wherein said outer spacer is movably mounted on said inner spacer.

18. The implant of claim 16 wherein:

at least one of said inner spacer and said outer spacer is selected from the group consisting of polyetheretherketone and polyetherketoneketone.

19. The implant of claim 16 wherein said spacer is one of elliptical-shaped, cylindrical-shaped, ovoid-shaped, oval-shaped, track-shaped and rectangular-shaped with curved-ends.

20. The implant of claim 16 wherein said spacer is selected from the group consisting of:

polyetheretherketone, polyetherketoneketone, a polyaryletheretherketone, a high molecular weight polymer, a thermoplastic, and a polycarbonate urethane.

21. The implant of claim 16 wherein said inner spacer and said outer spacer is selected from the group consisting of polyetheretherketone and polyetherketoneketone.

23. The implant of claim 16 wherein:

said inner spacer has flattened upper and lower portions and rounded first and second end, and

said outer spacer has flattened upper and lower portions and rounded first and second ends.

24. The implant of claim 16 wherein:

said inner spacer has upper and lower outer portions; and

said outer spacer has upper and lower inner portions; and

wherein said upper portions of said outer spacer are spaced from the upper portion of said inner spacer; and

wherein said lower portions of said outer spacer is spaced from the lower portion of said inner spacer.

25. The implant of claim 16 wherein said spacer is comprised of a material that is deflectable.

26. The implant of claim 16 wherein said spacer is comprised of a material that is sufficiently deflectable so that said outer spacer can be urged into contact with the inner spacer with the implant placed between spinous processes of a human and with the human bending backwards.

27. The implant of claim 16 wherein:

said inner spacer has flattened upper and lower portions; and

said outer spacer has flattened upper and lower portions; and

wherein said upper portion of said outer spacer is spaced from the upper portion of said inner spacer; and

wherein said lower portion of said outer spacer is spaced from the lower portion of said inner spacer; and

wherein said spacer is comprised of a material that is sufficiently deflectable so that said flattened upper and lower portion of said outer spacer can be urged into contact with the respective flattened upper and lower portions of said inner spacer with the implant placed between spinous processes of a human and with the human bending backwards.

28. The implant of claim 16 wherein:

said spacer has dimension of selected from the group consisting of 6 mm, 8 mm, 10 mm, 12 mm, and 14 mm.

29. The implant of claim 16 wherein:

said outer spacer can have an outer dimension selected from the group consisting of;

6 mm, 8 mm, 10 mm, 12 mm, and 14 mm; and

said inner spacer has flattened upper and lower portions; and

said outer spacer has flattened upper and lower portions; and

wherein said outer spacer is spaced from the upper portion of said inner spacer by about at least one quarter millimeter; and

wherein said outer spacer is spaced from the lower portion of said inner spacer by about at least one quarter millimeter.

30. The implant of claim 16 wherein said spacer has rounded ends, and upper and lower surfaces.

31. The implant of claim 16 wherein:

said inner spacer has upper and lower surfaces and rounded first and second end, and

said outer spacer has upper and lower surfaces and rounded first and second ends.

32. The implant of claim 16 wherein:

said inner spacer has an off-center bore that receives said shaft so that said spacer can rotate about said shaft.

33. The implant of claim 16 wherein:

said inner spacer is football-shaped in cross-section; and

said outer spacer has a cross-section selected from the group consisting of elliptical-shaped, cylindrical-shaped, ovoid-shaped, oval-shaped, track-shaped, and rectangle-shaped with curved ends.

34. The implant of claim 16 wherein:

said inner spacer has upper and lower surfaces and substantially pointed first and second end; and

said outer spacer has upper and lower surfaces and substantially rounded first and second ends.

35. The implant of claim 16 wherein:

said inner spacer has upper and lower portions and first and second end, and p1 said outer spacer has upper and lower portions and first and second ends; and

said respective ends are placed closer together than said respective portions.

46. The implant of claim 16 wherein the spacer has a dimension selected from about 6 mm to about 14 mm.

54. The implant of claim 16 wherein at least one of said inner spacer and said outer spacer is comprised of a polymer.

55. The implant of claim 16 wherein at least one of said inner spacer and said outer spacer is comprised of a thermoplastic.

56. The implant of claim 16 wherein at least one of said inner spacer and said outer spacer is comprised of a polyketone.

57. The implant of claim 16 wherein at least one of said inner spacer and said outer spacer is selected from the group consisting of polyetheretherketone, and polyetherketoneketone.

58. The implant of claim 16 wherein at least one of said inner spacer and said outer spacer is comprised of a polycarbonate urethane.

59. The implant of claim 16 wherein at least one of said inner spacer and said outer spacer is comprised of a urethane.

79. The implant of claim 16 wherein the spacer is radio-translucent.

80. The implant of claim 16 wherein the spacer is transparent to x-rays.

86. The implant of claim 16 wherein at least one of the inner spaces and the outer spaces is selected from polyetherketone, polyetherketoneetherketoneketone, polyetheretherketoneketone, polyaryletheretherketone, and titanium.

88. The spacer of claim 16 wherein:

said spacer has an off-center bore that receives said shaft so that said spacer can rotate about said shaft.

36. A spacer for use with an interspinous implant comprising:

an inner spacer adapted to be rotatably mounted on a shaft of the implant; and

an outer spacer mounted on the inner spacer.

37. A spacer according to claim 36 wherein the spacer is comprised of deflectable material.

38. A spacer according to claim 36 wherein the spacer is selected from the group consisting of:

polyetheretherketone, polyetherketoneketone, a polyaryletheretherketone, a high molecular weight polymer, a thermoplastic, and a polycarbonate urethane.

39. The spacer according to claim 36 wherein:

the inner spacer has a cross-section and shape selected from the group consisting of elliptical-shaped, cylindrical-shaped, ovoid-shaped, oval-shaped, track-shaped, and rectangular-shaped with curved ends.

40. The spacer of claim 36 wherein said spacer has a dimension selected from about 6 mm to about 14 mm.

41. The spacer of claim 36 wherein said spacer has a dimension selected from the group consisting of:

6 mm, 8 mm, 10 mm, 12 mm, and 14 mm.

42. The spacer of claim 36 wherein the outer spacer is movably mounted over the inner spacer.

81. The implant of claim 36 wherein the spacer is radio-translucent.

82. The implant of claim 36 wherein the spacer is translucent to x-rays.

89. The spacer of claim 36 wherein:

said spacer has an off-center bore that receives said shaft so that said spacer can rotate about said shaft.

44. In an implant that is locatable between spinous processes, the improvement comprising:

a spacer with an inner spacer that is rotatably mounted a shaft of the implant; and

said spacer having an outer spacer mounted on the inner spacer.

70. The implant of claim 44 wherein:

said inner spacer has flattened upper and lower portions and rounded first and second end, and

said outer spacer has flattened upper and lower portions and rounded first and second ends.

71. The implant of claim 44 wherein:

said inner spacer has flattened upper and lower portions; and

said outer spacer has flattened upper and lower portions; and

wherein said upper portion of said outer spacer is spaced from the upper portion of said inner spacer; and

wherein said lower portion of said outer spacer is spaced from the lower portion of said inner spacer; and

wherein said spacer is comprised of a material that is sufficiently deflectable so that said flattened upper and lower portion of said outer spacer can be urged into contact with the respective flattened upper and lower portions of said inner spacer with the implant placed between spinous processes of a human and with the human bending backwards.

72. The implant of claim 44 wherein at least one of said inner spacer and said outer spacer is selected from the group consisting of polyetheretherketone and polyetherketoneketone.

73. The implant of claim 44 wherein:

said inner spacer has upper and lower outer portions; and

said outer spacer has upper and lower inner portions; and

wherein said upper portion of said outer spacer are spaced from the upper portion of said inner spacer; and

wherein said lower portion of said outer spacer is spaced from the lower portion of said inner spacer.

74. The implant of claim 44 wherein the outer spacer is comprised of deflectable material.

87. The implant of claim 44 wherein one of the inner spacers and the outer spacers is selected from polyetherketone, polyetherketoneetherketoneketone and polyetheretherketoneketone, polyaryletheretherketone, and titanium.

47. In a spacer that is locatable between spinous processes, the improvement comprising:

an inner spacer with upper and lower surfaces; and

an outer spacer which is mounted over said inner spacer and spaced from said upper and lower surfaces of said inner spacer.

75. The implant of claim 47 wherein at least one of said inner spacer and said outer spacer is comprised of polyetheretherketone.

76. The implant of claim 47 wherein the outer spacer is comprised of deflective material.

60. An implant adapted to be placed between spinous processes comprising:

a body having a shaft extending therefrom;

a spacer that is mounted on the shaft; and

wherein said spacer is comprised of;

an inner spacer that is mounted on said shaft; and

an outer spacer that is mounted on said inner spacer.

61. The implant of claim 60 wherein said outer spacer is deflectable toward said inner spacer.

62. The implant of claim 60 wherein at least one of said inner spacer and said outer spacer is comprised of a polymer.

63. The implant of claim 60 wherein at least one of said inner spacer and said outer spacer is comprised of a thermoplastic.

64. The implant of claim 60 wherein at least one of said inner spacer and said outer spacer is comprised of a polyketone.

65. The implant of claim 60 wherein at least one of said inner spacer and said outer spacer is selected from the group consisting of polyetheretherketone and polyetherketoneketone.

66. The implant of claim 60 wherein at least one of said inner spacer and said outer spacer is comprised of a polycarbonate urethane.

67. The implant of claim 60 wherein at least one of said inner spacer and said outer spacer is comprised of a urethane.

83. The implant of claim 60 wherein the spacer is radio-translucent.

84. The implant of claim 60 wherein the spacer is transparent to x-rays.

68. An implant adapted to be placed between spinous processes comprising:

a body having a shaft extending therefrom;

a spacer that is rotatably mounted on the shaft; and

wherein said spacer is selected from the group consisting of;

a polymer, thermoplastic, polyketone, polyetheretherketone, polyetherketoneketone, polyaryletheretherketone, polycarbonate urethane, and urethane.

69. An implant adapted to be placed between spinous processes comprising:

a body having a shaft extending therefrom;

a spacer that is rotatably mounted on the shaft; and

wherein said spacer is selected from the group consisting of a polyetheretherketone and polyetherketoneketone.