Apparatus and method for anterior spinal stabilization

• US 20040034353A1
• Filed: 08/11/2003
• Published: 02/19/2004
• Est. Priority Date: 03/28/1994
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Michelson, Gary Karlin
• Granted Patent: US 7,255,698 B2
• Time in Patent Office: Days
• US Class Current: 606/61
• CPC Class Codes: A61B 17/025 Joint distractors
• CPC Class Codes: A61B 17/0642 for bones, e.g. for osteosynthesis or connecting tendon to bone
• CPC Class Codes: A61B 17/1757 for the spine
• CPC Class Codes: A61B 17/7059 Cortical plates A61B17/7007, A61B17/7058 take precedence
• CPC Class Codes: A61B 17/809 with bone-penetrating elements, e.g. blades or prongs bone staples A61B17/0642; intramedullary nails with a plate at an end A61B17/7233
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61B 17/8665 Nuts
• CPC Class Codes: A61B 17/92 Impactors or extractors, e.g. for removing intramedullary devices insertion or extraction of artificial joints A61F2/4603
• CPC Class Codes: A61B 2017/00004 (bio)absorbable, (bio)resorbable or resorptive
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61B 2017/0641 having at least three legs as part of one single body
• CPC Class Codes: A61B 2017/0647 having one single leg, e.g. tacks
• CPC Class Codes: A61B 2017/0648 threaded, e.g. tacks with a screw thread
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• 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 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/446 having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30235 : tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30329 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2002/30433 : using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30774 : internally-threaded
• CPC Class Codes: A61F 2002/30785 : parallel
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30836 : knurled
• CPC Class Codes: A61F 2002/3085 : with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• CPC Class Codes: A61F 2002/30904 : serrated profile, i.e. saw-toothed
• 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 2210/0004 : bioabsorbable
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• 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 2310/00059 : Chromium or Cr-based alloys
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite

Abstract

A spinal fixation device for stabilizing one or more segments of the human spine and for preventing the dislodgement of intervertebral spinal fusion implants, which remains permanently fixated once applied. The spinal fixation device of the present invention comprises of a staple member made of material appropriate for human surgical implantation which is of sufficient length to span the disc space between two adjacent vertebrae and to engage, via essentially perpendicular extending projections, the vertebrae adjacent to that disc space. A portion of the staple of the spinal fixation device interdigitates with an already implanted intervertebral spinal fusion implant which itself spans the disc space to engage the adjacent vertebrae, and the spinal fixation deice is bound to the spinal fusion implant by a locking means. The spinal fixation device of the present invention is of great utility in restraining the vertebrae adjacent to the spinal fusion implant from moving apart as the spine is extended and also serves as an anchor for a multi-segmental spinal alignment means for aligning more that one segment of the spine.

Claims

1. An apparatus for stabilizing vertebral bodies adjacent a disc space of a human spine, said apparatus comprising:

an interbody spinal fusion implant adapted to be surgically implanted at least in part within the disc space between the adjacent vertebral bodies in a segment of the spine, said implant comprising upper and lower portions for contacting each of the adjacent vertebral bodies when positioned therein, each of said upper and lower portions having at least one opening adapted to communicate with one of the adjacent vertebral bodies, said openings of said upper and lower portions being in communication with one another and adapted for permitting for the growth of bone from adjacent vertebral body to adjacent vertebral body through said implant, said implant having an insertion end for entry into the spine and a trailing end opposite said insertion end; and

a spinal fixation device coupled to said trailing end of said spinal implant and adapted to be attached to each of the adjacent vertebral bodies, said spinal fixation device having a length sufficient to span the disc space and connect to each of the vertebral bodies adjacent to the disc space.

2. The apparatus of claim 1, wherein said spinal fixation device comprises at least a first opening formed therethrough to receive a first fastener to secure said spinal fixation device to one of the vertebral bodies and at least a second opening formed therethrough to receive a second fastener to secure said spinal fixation device to another one of the vertebral bodies.

3. The apparatus of claim 1, further comprising at least one opening adapted to receive a fastener to secure said spinal fixation device to said spinal implant.

4. The apparatus of claim 1, wherein said spinal fixation device has a top member having a longitudinal axis and a horizontal axis transverse to the longitudinal axis, said top member having a plurality of openings therethrough, at least a first pair of said openings being aligned along the longitudinal axis and at least a second pair of said openings being aligned along the horizontal axis.

5. The apparatus of claim 4, wherein said first pair of openings are adapted to receive a fastener for securing said spinal fixation device to the vertebral bodies.

6. The apparatus of claim 4, wherein said second pair of openings are adapted to receive a fastener for securing said spinal fixation device to said spinal implant.

7. The apparatus of claim 1, wherein said spinal fixation device comprises at least two fasteners for attaching said spinal fixation device to each of the adjacent vertebral bodies.

8. The apparatus of claim 7, wherein said fasteners include at least one of a screw and a prong.

9. The apparatus of claim 1, wherein said spinal fixation device has a top member having a lower facing portion adapted to face said spinal implant and the vertebral bodies and an upper facing portion opposite said lower facing portion.

10. The apparatus of claim 9, wherein said lower facing portion has a first end portion for contacting one of the adjacent vertebral bodies, a second end portion adapted to contact another of the adjacent vertebral bodies, and a middle portion between said first and second end portions for contacting said spinal implant, said middle portion being at least in part in a first plane and said first and second portions being at least in part in a second plane different than said first plane.

11. The apparatus of claim 10, wherein said middle portion protrudes from said lower facing portion of said top member to form a leading wall and opposite side walls, said opposite side walls being at an angle to said first and second end portions of said lower facing portion.

12. The apparatus of claim 11, wherein said opposite side walls are generally perpendicular to said first and second end portions of said lower facing portion.

13. The apparatus of claim 1, wherein said spinal fixation device is generally triangular in shape.

14. The apparatus of claim 1, wherein approximately one half of said spinal fixation device is generally triangular in shape.

15. The apparatus of claim 1, wherein said spinal fixation device has a opposite ends, opposite sides, and a longitudinal axis passing through said ends, said opposite sides proximate a mid-point between said opposite ends being spaced apart a greater distance than proximate said opposite ends.

16. The apparatus of claim 15, wherein said opposite sides are tapered toward each other proximate said opposite ends.

17. The apparatus of claim 1, wherein at least a portion of said upper and lower portions of said spinal implant are arcuate along at least a portion of their length.

18. The apparatus of claim 1, wherein said upper and lower portions of said spinal implant further comprise a protrusion for engaging the adjacent vertebral bodies.

19. The apparatus of claim 18, wherein said protrusion is a thread.

20. The apparatus of claim 1, wherein said implant has a hollow interior, at least one of said insertion and trailing ends of said spinal implant is being open for loading bone growth promoting material into said hollow interior.

21. The apparatus of claim 20, further comprising an end cap for closing said open end.

22. The apparatus of claim 20, wherein said hollow interior is a chamber and the bone growth promoting material includes a bone graft.

23. The apparatus of claim 1, wherein said spinal implant includes an artificial material other than bone.

24. The apparatus of claim 1, wherein said implant comprises harvested bone.

25. The apparatus of claim 1, wherein said implant is in combination with bone growth promoting material.

26. The apparatus of claim 25, wherein said bone growth promoting material includes at least one of hydroxyapatite and bone morphogenetic protein.

27. The apparatus of claim 1, wherein said implant is treated with a bone growth promoting substance.

28. The apparatus of claim 1, wherein said implant is a source of osteogenesis.

29. The apparatus of claim 1, wherein said implant is at least in part bioabsorbable.

30. The apparatus of claim 1, wherein said implant comprises metal.

31. The apparatus of claim 1, wherein said implant comprises a plastic material.

32. The apparatus of claim 1, wherein said implant comprises a ceramic material.

33. The apparatus of claim 1, wherein said implant is formed of a porous material.

34. The apparatus of claim 1, wherein said implant is formed of a material that intrinsically participates in the growth of bone from adjacent vertebral body to adjacent vertebral body through said implant.

35. The apparatus of claim 1, wherein said implant is in combination with harvested bone.

36. An apparatus for replacing a portion of an anterior longitudinal ligament that has been at least in part surgically removed to access a disc space between two adjacent vertebral bodies of a human spine, said apparatus comprising:

an interbody spinal fusion implant adapted to be surgically implanted at least in part within the disc space between the two adjacent vertebral bodies in a segment of the spine, said implant comprising upper and lower portions for contacting each of the adjacent vertebral bodies when positioned therein, each of said upper and lower portions having at least one opening adapted to communicate with one of the adjacent vertebral bodies, said openings of said upper and lower portions being in communication with one another and adapted for permitting for the growth of bone from adjacent vertebral body to adjacent vertebral body through said implant, said implant having an insertion end for entry into the spine and a trailing end opposite said insertion end; and

an anterior longitudinal ligament replacement member coupled to said trailing end of said spinal implant and adapted to be attached to each of the two adjacent vertebral bodies, said ligament replacement member having a length sufficient to span the disc space and connect to each of the vertebral bodies adjacent to the disc space to replace at least a portion of the removed anterior longitudinal ligament.

37. The apparatus of claim 36, wherein said ligament replacement member comprises at least a first opening formed therethrough to receive a first fastener to secure said ligament replacement member to one of the vertebral bodies and at least a second opening formed therethrough to receive a second fastener to secure said ligament replacement member to another one of the vertebral bodies.

38. The apparatus of claim 36, further comprising at least one opening adapted to receive a fastener to secure said ligament replacement member to said spinal implant.

39. The apparatus of claim 36, wherein said ligament replacement member has a top member having a longitudinal axis and a horizontal axis transverse to the longitudinal axis, said top member having a plurality of openings therethrough, at least a first pair of said openings being aligned along the longitudinal axis and at least a second pair of said openings being aligned along the horizontal axis.

40. The apparatus of claim 39, wherein said first pair of openings are adapted to receive a fastener for securing said ligament replacement member to the vertebral bodies.

41. The apparatus of claim 39, wherein said second pair of openings are adapted to receive a fastener for securing said ligament replacement member to said spinal implant.

42. The apparatus of claim 36, wherein said ligament replacement member comprises at least two fasteners for attaching said ligament replacement member to each of the adjacent vertebral bodies.

43. The apparatus of claim 42, wherein said fasteners include at least one of a screw and a prong.

44. The apparatus of claim 36, wherein said ligament replacement member has a top member having a lower facing portion adapted to face said spinal implant and the vertebral bodies and an upper facing portion opposite said lower facing portion.

45. The apparatus of claim 44, wherein said lower facing portion has a first end portion for contacting one of the adjacent vertebral bodies, a second end portion adapted to contact another of the adjacent vertebral bodies, and a middle portion between said first and second end portions for contacting said spinal implant, said middle portion being at least in part in a first plane and said first and second portions being at least in part in a second plane different than said first plane.

46. The apparatus of claim 45, wherein said middle portion protrudes from said lower facing portion of said top member to form a leading wall and opposite side walls, said opposite side walls being at an angle to said first and second end portions of said lower facing portion.

47. The apparatus of claim 46, wherein said opposite side walls are generally perpendicular to said first and second end portions of said lower facing portion.

48. The apparatus of claim 36, wherein said ligament replacement member is generally triangular in shape.

49. The apparatus of claim 36, wherein approximately one half of said ligament replacement member is generally triangular in shape.

50. The apparatus of claim 36, wherein said ligament replacement member has a opposite ends, opposite sides, and a longitudinal axis passing through said ends, said opposite sides proximate a mid-point between said opposite ends being spaced apart a greater distance than proximate said opposite ends.

51. The apparatus of claim 50, wherein said opposite sides are tapered toward each other proximate said opposite ends.

52. The apparatus of claim 36, wherein at least a portion of said upper and lower portions of said spinal implant are arcuate along at least a portion of their length.

53. The apparatus of claim 36, wherein said upper and lower portions of said spinal implant further comprise a protrusion for engaging the adjacent vertebral bodies.

54. The apparatus of claim 53, wherein said protrusion is a thread.

55. The apparatus of claim 36, wherein said implant has a hollow interior, at least one of said insertion and trailing ends of said spinal implant is being open for loading bone growth promoting material into said hollow interior.

56. The apparatus of claim 55, further comprising an end cap for closing said open end.

57. The apparatus of claim 55, wherein said hollow interior is a chamber and the bone growth promoting material includes a bone graft.

58. The apparatus of claim 36, wherein said spinal implant includes an artificial material other than bone.

59. The apparatus of claim 36, wherein said implant comprises harvested bone.

60. The apparatus of claim 36, wherein said implant is in combination with bone growth promoting material.

61. The apparatus of claim 60, wherein said bone growth promoting material includes at least one of hydroxyapatite and bone morphogenetic protein.

62. The apparatus of claim 36, wherein said implant is treated with a bone growth promoting substance.

63. The apparatus of claim 36, wherein said implant is a source of osteogenesis.

64. The apparatus of claim 36, wherein said implant is at least in part bioabsorbable.

65. The apparatus of claim 36, wherein said implant comprises metal.

66. The apparatus of claim 36, wherein said implant comprises a plastic material.

67. The apparatus of claim 36, wherein said implant comprises a ceramic material.

68. The apparatus of claim 36, wherein said implant is formed of a porous material.

69. The apparatus of claim 36, wherein said implant is formed of a material that intrinsically participates in the growth of bone from adjacent vertebral body to adjacent vertebral body through said implant.

70. The apparatus of claim 36, wherein said implant is in combination with harvested bone.

71. A method for stabilizing two vertebral bodies adjacent a disc space of a human spine, comprising the steps of:

removing at least a portion of an anterior longitudinal ligament of a segment of the human spine to access the disc space;

forming an implantation space across the disc space and into a portion of the adjacent vertebral bodies;

implanting an interbody spinal implant adapted to be surgically implanted at least in part within the implantation space, the spinal implant being adapted to contact both of the vertebral bodies adjacent to the disc space when the disc space has been restored to approximate a normal height for the disc space; and

replacing the removed portion of the anterior longitudinal ligament by attaching an anterior longitudinal ligament replacement member to each of the two adjacent vertebral bodies, the ligament replacement member being coupled to the spinal implant, the ligament replacement member having a length sufficient to span the disc space and to contact each of the two adjacent vertebral bodies and the spinal implant.

72. The method of claim 71, further comprising the step of using at least a first fastener to secure the ligament replacement member to one of the vertebral bodies and at least a second fastener to secure said ligament replacement member to another one of the vertebral bodies.

73. The method of claim 71, further comprising the step of using a fastener to secure said ligament replacement member to said spinal implant.

74. The method of claim 72, wherein said fasteners include at least one of a screw and a prong.

75. The method of claim 71, wherein said implanting step includes implanting the spinal implant having at least a portion of the upper and lower portions being arcuate along at least a portion of their length.

76. The method of claim 71, wherein said implanting step includes implanting the spinal implant having upper and lower portions comprising a protrusion for engaging the adjacent vertebral bodies.

77. The method of claim 76, wherein said protrusion is a thread.

78. The method of claim 71, wherein said implanting step includes implanting the spinal implant in combination with harvested bone.

79. The method of claim 71, wherein said implanting step includes implanting the spinal implant in combination with bone growth promoting material.

80. The method of claim 79, wherein said bone growth promoting material includes at least one of hydroxyapatite and bone morphogenetic protein.

81. A spinal system comprising:

a first implant including a first body portion positionable in a disc space between adjacent upper and lower vertebral bodies;

a second implant including a second body portion positionable in the disc space between adjacent upper and lower vertebral bodies; and

a ligament replacement member extending from each of said first body portion and said second body portion and positionable along the upper vertebral body and along the lower vertebral body when said first body portion and said second body portion are positioned in the disc space.

82. The system of claim 81, wherein said first body portion has a leading end and an opposite trailing end, and said ligament replacement member is attached to said trailing end of said first body portion.

83. The system of claim 81, wherein each of said first and second body portions includes an upper bearing surface and a lower bearing surface separated by a height, said height adapted to maintain spacing between the adjacent vertebral bodies.

84. The system of claim 83, wherein each of said upper and lower bearing surfaces of each of said first and second body portions includes a bone engaging surface to inhibit expulsion of said implant from the disc space.

85. The system of claim 84, wherein each of said first and second body portions is configured for rotatable insertion into the disc space and each of said bone engaging surfaces is threaded.

86. The system of claim 81, wherein at least one of said first and second body portions is shaped for push-in insertion into the disc space.

87. The system of claim 81, wherein said first and second implants are spinal fusion devices.

88. The system of claim 81, wherein said ligament replacement member comprises:

a first opening formed therethrough to receive a first fastener to secure the ligament replacement member to the upper vertebral body; and

a second opening formed therethrough to receive a second fastener to secure the ligament replacement member to the lower vertebral body.

89. The system of claim 81, wherein said ligament replacement member is removably attachable to at least one of said first and second body portions.