Apparatus and method for sequential distraction

• US 20060142762A1
• Filed: 02/18/2006
• Published: 06/29/2006
• Est. Priority Date: 06/10/1993
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Michelson, Gary Karlin
• Granted Patent: US 7,887,565 B2
• Time in Patent Office: Days
• US Class Current: 606/86.A
• CPC Class Codes: A61B 17/025 Joint distractors
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61B 17/1757 for the spine
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: Y10S 623/908 Bone
• CPC Class Codes: Y10T 407/1964 Arcuate cutting edge

Abstract

Apparatus and a method of inserting spinal implants is disclosed in which an intervertebral space is first distracted, a hollow sleeve having teeth at one end is then driven into the vertebrae adjacent that disc space. A drill is then passed through the hollow sleeve removing disc and bone in preparation for receiving the spinal implant which is then inserted through the sleeve.

Claims

1. A system for spacing apart an upper vertebral body and a lower vertebral body adjacent a disc space in a human spine, the system comprising:

a first distractor having a proximal end, a distal end, and a first thickness adapted to separate the upper vertebral body from the lower vertebral body along the first thickness, the first distractor being configured to contact at least a portion of the endplates of the upper vertebral body and the lower vertebral body;

a second distractor having a proximal end, a distal end, and a second thickness that is greater than the first thickness, the second distractor adapted to separate the upper vertebral body from the lower vertebral body along the second thickness, the second distractor being configured to contact at least a portion of the endplates of the upper vertebral body and the lower vertebral body; and

a distraction maintenance device having an upper surface, a lower surface, an insertion end, and a trailing end, the distraction maintenance device having a height adapted to maintain a space between the upper vertebral body and the lower vertebral body.

2. The system of claim 1, wherein the distal end of the first distractor is tapered for wedging between the upper vertebral body and the lower vertebral body.

3. The system of claim 1, wherein the distal end of the first distractor is bullet-shaped.

4. The system of claim 1, wherein the distal end of the first distractor is substantially the same shape as the insertion end of the distraction maintenance device.

5. The system of claim 1, wherein the distal end of the second distractor is tapered for wedging between the upper vertebral body and the lower vertebral body.

6. The system of claim 1, wherein the distal end of the second distractor is bullet-shaped.

7. The system of claim 1, wherein the distal end of the second distractor is substantially the same shape as the insertion end of the distraction maintenance device.

8. The system of claim 1, wherein the first thickness and the second thickness are diameters.

9. The system of claim 1, wherein the distraction maintenance device comprises surface irregularities on at least one of the upper surface and the lower surface.

10. The system of claim 9, wherein the surface irregularities include at least one of ratchetings and knurling.

11. The system of claim 9, wherein the surface irregularities are oriented to resist proximal migration of the distraction maintenance device more than the surface irregularities resist distal migration of the distraction maintenance device.

12. The system of claim 1, wherein the distraction maintenance device comprises opposite sidewalls between the upper surface and the lower surface.

13. The system of claim 12, wherein the opposite sidewalls are substantially planar.

14. The system of claim 1, wherein the distraction maintenance device has a length and a mid-longitudinal axis, the distraction maintenance device having a generally rectangular cross section transverse to the mid-longitudinal axis along at least a portion of the length of the distraction maintenance device.

15. The system of claim 1, further comprising an inserter adapted to cooperatively engage the distraction maintenance device.

16. The system of claim 1, wherein the trailing end of the distraction maintenance device is configured to cooperatively engage an inserter for inserting the distraction maintenance device between the upper vertebral body and the lower vertebral body.

17. The system of claim 1, further comprising a guard for providing protected access to the upper vertebral body and the lower vertebral body, the guard having a passage configured to permit the distraction maintenance device to be inserted therethrough.

18. The system of claim 1, further comprising a tissue removal device for removing at least a portion of a spinal disc between the upper vertebral body and the lower veterbral body.

19. The system of claim 18, wherein the tissue removal device is a rotating cutter.

20. The system of claim 1, further comprising a distractor puller for removing the distractors from between the upper vertebral body and the lower body.

21. A distraction maintenance device for insertion between an upper vertebral body and a lower vertebral body adjacent a disc space of a human spine, the device comprising:

an upper surface for contacting an endplate of the upper vertebral body;

a lower surface for contacting an endplate of the lower vertebral body;

a trailing end configured to cooperatively engage an inserter; and

an insertion end being at least in part curvilinear and adapted to facilitate introduction into the disc space to distract the upper vertebral body away from the lower vertebral body;

at least one of the upper surface and the lower surface includes bone engaging projections having a distal sloped surface and a proximal sloped surface, a plane containing at least a portion of the distal sloped surface and a plane containing at least a portion of the proximal sloped surface intersect.

22. The distraction maintenance device of claim 21, wherein the curvilinear insertion end includes a convex arc between the upper surface and the lower surface.

23. The distraction maintenance device of claim 21, wherein the curvilinear insertion end is bullet-shaped.

24. The distraction maintenance device of claim 21, further comprising opposite sidewalls between the upper surface and the lower surface.

25. The distraction maintenance device of claim 24, wherein the opposite sidewalls are substantially planar.

26. The distraction maintenance device of claim 21, wherein the bone engaging projections are ratchetings.

27. The distraction maintenance device of claim 21, wherein the bone engaging projections are oriented to resist proximal migration of the distraction maintenance device more than the bone engaging projections resist distal migration of the distraction maintenance device.

28. The distraction maintenance device of claim 21, wherein the distal sloped surface is longer than the proximal sloped surface.

29. The distraction maintenance device of claim 21, wherein projections of the distal sloped surface and the proximal sloped surface meet at an obtuse angle.

30. The distraction maintenance device of claim 21, wherein projections of the distal sloped surface and the proximal sloped surface meet at an acute angle.

31. The distraction maintenance device of claim 21, wherein the distraction maintenance device has a length and a mid-longitudinal axis along the length, the distraction maintenance device having a generally rectangular cross section transverse to the mid-longitudinal axis along at least a portion of the length of the distraction maintenance device.

32. The distraction maintenance device of claim 21, wherein the trailing end of the distraction maintenance device includes a recess adapted to receive at least a portion of the inserter for inserting the distraction maintenance device between the upper vertebral body and the lower vertebral body.

33. A method of distracting an upper vertebral body from a lower vertebral body adjacent a disc space of a human spine, the method comprising the steps of:

inserting a first distractor having a first thickness in contact with at least a portion of the endplates of the upper vertebral body and the lower vertebral body;

inserting a second distractor having a second thickness that is greater than the first thickness in contact with at least a portion of the endplates of the upper vertebral body and the lower vertebral body; and

inserting between the upper vertebral body and the lower vertebral body a distraction maintenance device having an upper surface, a lower surface, an insertion end, and a trailing end.

34. The method of distracting of claim 33, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with opposite sidewalls between the upper surface and the lower surface.

35. The method of distracting of claim 34, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with substantially planar opposite sidewalls.

36. The method of distracting of claim 33, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with bone engaging projections on at least one of the upper surface and the lower surface.

37. The method of distracting of claim 36, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with bone engaging projections that are ratchetings.

38. The method of distracting of claim 36, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with bone engaging projections that are oriented to resist proximal migration of the distraction maintenance device more than the bone engaging projections resist distal migration of the distraction maintenance device.

39. The method of claim 33, wherein the method is performed as a bilateral procedure.

40. The method of claim 33, wherein at least one of the steps of inserting the first and second distractors and the distraction maintenance device are performed through a guard.

41. The method of claim 33, further comprising the step of inserting a fusion promoting material between the upper and lower vertebral bodies.

42. A method of distracting an upper vertebral body from a lower vertebral body adjacent a disc space in the human spine, the lower vertebral body being connected to the upper vertebral body by one or more tissue structures, the method comprising the steps of:

sequentially inserting and removing at least two distractors of progressively greater thicknesses into the disc space and in contact with at least a portion of the endplates of the upper vertebral body and the lower vertebral body until at least one of the following sub-steps occurs;

(a) a normal height between the upper vertebral body and the lower vertebral body is achieved,

(b) the tissue structures between the upper vertebral body and the lower vertebral body become tensioned to increase stability between the upper vertebral body and the lower vertebral body, and

(c) a surgeon determines that the stability between the upper vertebral body and the lower vertebral body adequately resists further distraction; and

inserting between the upper vertebral body and the lower vertebral body a distraction maintenance device with an upper surface, a lower surface, an insertion end, and a trailing end.

43. The method of distracting of claim 42, wherein the step of sequentially inserting and removing at least two distractors includes inserting and removing distractors of progressively greater diameters.

44. The method of distracting of claim 42, wherein the step of inserting a distraction maintenance device includes inserting a device with substantially the same shape as the last distractor sequentially inserted in the step of sequentially inserting and removing at least two distractors.

45. The method of distracting of claim 42, wherein the step of inserting a distraction maintenance device includes inserting a device with substantially the same insertion end shape as a proximal end of the last distractor sequentially inserted in the step of sequentially inserting and removing at least two distractors.

46. The method of distracting of claim 42, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with a curvilinear insertion end.

47. The method of distracting of claim 42, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with a convex arc between the upper surface and the lower surface.

48. The method of distracting of claim 42, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with a bullet-shaped insertion end.

49. The method of distracting of claim 42, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with opposite sidewalls between the upper surface and the lower surface.

50. The method of distracting of claim 49, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with substantially planar opposite sidewalls.

51. The method of distracting of claim 42, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with bone engaging projections on at least one of the upper surface and the lower surface.

52. The method of distracting of claim 51, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with bone engaging projections that are ratchetings.

53. The method of distracting of claim 51, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with bone engaging projections that are oriented to resist proximal migration of the distraction maintenance device more than the bone engaging projections resist distal migration of the distraction maintenance device.

54. The method of claim 42, wherein the method is performed as a bilateral procedure.

55. The method of claim 42, wherein at least one of the steps of inserting the first and second distractors and the distraction maintenance device are performed through a guard.

56. The method of claim 42, further comprising the step of inserting a fusion promoting material between the upper and lower vertebral bodies.

57. A method of determining an effective distraction of an upper vertebral body from a lower vertebral body adjacent a disc space in a human spine, the lower vertebral body being connected to the upper vertebral body by one or more tissue structures, the method comprising the steps of:

inserting a first distractor having a first thickness into the disc space and in contact with at least a portion of the endplates of the upper vertebral body and the lower vertebral body, the first thickness being sufficient to move the upper vertebral body and the lower vertebral body apart;

determining if the fit of the first distractor is sufficiently tight in the disc space to achieve a desired amount of distraction of the upper vertebral body and the lower vertebral body, and performing one of the following additional steps;

(a) inserting a distraction maintenance device between the upper vertebral body and the lower vertebral body if the fit of the first distractor is sufficiently tight in the disc space to achieve a desired amount of distraction of the upper vertebral body and the lower vertebral body;

or

(b) sequentially inserting additional distractors of thicknesses that are sequentially greater than the first thickness between the upper vertebral body and the lower vertebral body if the fit of the first distractor is not sufficiently tight in the disc space until the fit of a distractor is sufficiently tight in the disc space to achieve the desired amount of distraction of the upper vertebral body and the lower vertebral body, and then inserting a distraction maintenance device between the upper vertebral body and the lower vertebral body.

58. The method of claim 57, wherein the step of inserting the first distractor includes impacting the first distractor to move the distractor inbetween the upper vertebral body and the lower vertebral body.

59. The method of claim 57, wherein the step of determining if the fit of the first distractor is sufficiently tight includes at least one of pushing, pulling, sliding, and applying torque to the first distractor.

60. The method of claim 57, wherein the step of determining if the fit of the first distractor is sufficiently tight includes assessing forces applied to the tissue structures.

61. The method of claim 57, wherein the step of sequentially inserting distractors includes impacting the distractors to move the distractors inbetween the upper vertebral body and the lower vertebral body.

62. The method of claim 57, wherein the step of inserting the distraction maintenance device includes impacting the distraction maintenance device to move the distraction maintenance device inbetween the upper vertebral body and the lower vertebral body.

63. The method of claim 57, wherein the step of inserting a distraction maintenance device includes inserting the distraction maintenance device having substantially the same shape as the last distractor inserted.

64. The method of claim 57, wherein the step of inserting a distraction maintenance device includes inserting the distraction maintenance device having substantially the same insertion end shape as a proximal end of the last distractor sequentially inserted.

65. The method of claim 57, wherein the step of inserting the first distractor is performed through a guard.

66. The method of claim 57, wherein the method is performed as a bilateral procedure.

67. The method of claim 57, further comprising the step of inserting a fusion promoting material between the upper and lower vertebral bodies.

68. A system for spacing apart an upper vertebral body and a lower vertebral body adjacent a disc space in a human spine, the system comprising:

a first distractor having a proximal end, a distal end, and a first thickness adapted to separate the upper vertebral body from the lower vertebral body along the first thickness, the first distractor being configured to contact at least a portion of the upper vertebral body and the lower vertebral body;

a second distractor having a proximal end, a distal end, and a second thickness that is greater than the first thickness, the second distractor adapted to separate the upper vertebral body from the lower vertebral body along the second thickness, the second distractor being configured to contact at least a portion of the upper vertebral body and the lower vertebral body; and

a distraction maintenance device having an upper surface, a lower surface, an insertion end, and a trailing end, the distraction maintenance device having a height adapted to maintain a space between the upper vertebral body and the lower vertebral body, the insertion end having a rounded portion from the upper surface to the lower surface of the distraction maintenance device.

69. The system of claim 68, wherein the distal end of the first distractor is tapered for wedging between the upper vertebral body and the lower vertebral body.

70. The system of claim 68, wherein the distal end of the first distractor is bullet-shaped.

71. The system of claim 68, wherein the distal end of the first distractor is substantially the same shape as the insertion end of the distraction maintenance device.

72. The system of claim 68, wherein the first thickness and the second thickness are diameters.

73. The system of claim 68, wherein the distraction maintenance device comprises surface irregularities on at least one of the upper surface and the lower surface.

74. The system of claim 73, wherein the surface irregularities include at least one of ratchetings and knurling.

75. The system of claim 73, wherein the surface irregularities are oriented to resist proximal migration of the distraction maintenance device more than the surface irregularities resist distal migration of the distraction maintenance device.

76. The system of claim 68, wherein the distraction maintenance device comprises opposite sidewalls between the upper surface and the lower surface.

77. The system of claim 76, wherein the opposite sidewalls are substantially planar.

78. The system of claim 68, wherein the distraction maintenance device has a length and a mid-longitudinal axis, the distraction maintenance device having a generally rectangular cross section transverse to the mid-longitudinal axis along at least a portion of the length of the distraction maintenance device.

79. The system of claim 68, further comprising an inserter adapted to cooperatively engage the distraction maintenance device.

80. The system of claim 68, wherein the trailing end of the distraction maintenance device is configured to cooperatively engage an inserter for inserting the distraction maintenance device between the upper vertebral body and the lower vertebral body.

81. The system of claim 68, further comprising a guard for providing protected access to the upper vertebral body and the lower vertebral body, the guard having a passage configured to permit the distraction maintenance device to be inserted therethrough.

82. The system of claim 68, further comprising a tissue removal device for removing at least a portion of a spinal disc between the upper vertebral body and the lower veterbral body.

83. The system of claim 82, wherein the tissue removal device is a rotating cutter.

84. The system of claim 68, further comprising a distractor puller for removing the distractors from between the upper vertebral body and the lower body.

85. A method of distracting an upper vertebral body from a lower vertebral body adjacent a disc space of a human spine, the method comprising the steps of:

inserting a first distractor having a first thickness in contact with at least a portion of the upper vertebral body and the lower vertebral body;

inserting a second distractor having a second thickness that is greater than the first thickness in contact with at least a portion of the upper vertebral body and the lower vertebral body; and

inserting between the upper vertebral body and the lower vertebral body a distraction maintenance device having an upper surface, a lower surface, an insertion end, and a trailing end, the insertion end having a rounded portion from the upper surface to the lower surface of the distraction maintenance device.

86. The method of claim 85, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with opposite sidewalls between the upper surface and the lower surface.

87. The method of claim 86, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with substantially planar opposite sidewalls.

88. The method of claim 85, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with bone engaging projections on at least one of the upper surface and the lower surface.

89. The method of claim 88, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with bone engaging projections that are ratchetings.

90. The method of claim 88, wherein the step of inserting a distraction maintenance device includes inserting a distraction maintenance device with bone engaging projections that are oriented to resist proximal migration of the distraction maintenance device more than the bone engaging projections resist distal migration of the distraction maintenance device.

91. The method of claim 85, wherein the method is performed as a bilateral procedure.

92. The method of claim 85, wherein the steps of inserting the first and second distractors are performed through a guard.

93. The method of claim 85, further comprising the step of inserting a fusion promoting material between the upper and lower vertebral bodies.