Apparatus and method for sequential distraction
View Patent ↗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.
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, a trailing end, a mid-longitudinal axis extending through the trailing end and the insertion end, and a length extending between the trailing end and the insertion end, and a plurality of non-threaded ratchets on the upper and lower surfaces, the distraction maintenance device having a height adapted to maintain a space between the upper vertebral body and the lower vertebral body, the plurality of non-threaded ratchets on the upper surface adapted to contact the endplate of the upper vertebral body, the plurality of non-threaded ratchets on the lower surface adapted to contact the endplate of the lower vertebral body, and each ratchet of the plurality of non-threaded ratchets having a distal sloped surface facing the insertion end and a proximal sloped surface facing the trailing end, the distal sloped surface adapted to facilitate insertion of the distraction maintenance device between the upper and lower vertebral bodies, the proximal sloped surface adapted to resist expulsion of the distraction maintenance device from between the upper and lower vertebral bodies, the distal sloped surface and the proximal sloped surface intersecting one another.
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 plurality of non-threaded ratchets are oriented to resist proximal migration of the distraction maintenance device more than the plurality of non-threaded ratchets resist distal migration of the distraction maintenance device.
10. The system of claim 1 , wherein the distraction maintenance device comprises opposite sidewalls between the upper surface and the lower surface.
11. The system of claim 10 , wherein the opposite sidewalls are substantially planar along a substantial portion of the length of the distraction maintenance device.
12. The system of claim 1 , wherein the distraction maintenance device has a generally rectangular cross section transverse to the mid-longitudinal axis along at least a portion of the length of the distraction maintenance device.
13. The system of claim 1 , further comprising an inserter adapted to cooperatively engage the distraction maintenance device.
14. 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.
15. 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.
16. 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.
17. The system of claim 16 , wherein the tissue removal device is a rotating cutter.
18. The system of claim 1 , further comprising a distractor puller for removing the distractors from between the upper vertebral body and the lower body.
19. The system of claim 1 , wherein, for each ratchet of the plurality of non-threaded ratchets, the intersection between the distal sloped surface and the proximal sloped surface forms a peak.
20. The system of claim 1 , wherein the distal sloped surface of a first of the plurality of non-threaded ratchets intersects the proximal sloped surface of a second of the plurality of non-threaded ratchets.
21. The system of claim 1 , wherein each of the plurality of non-threaded ratchets has a generally triangular shape in a place parallel to the mid-longitudinal axis and passing through the upper and lower surfaces.
22. The system of claim 1 , further comprising a slot formed in the trailing end.
23. The system of claim 22 , further comprising a circular hole positioned in the slot.
24. The system of claim 1 , further comprising at least three non-threaded ratchets of the plurality of non-threaded ratchets on one of the upper and lower surfaces.
25. The system of claim 1 , further comprising at least four non-threaded ratchets of the plurality of non-threaded ratchets on one of the upper and lower surfaces.
26. The system of claim 1 , wherein the upper surface is covered by distal sloped surfaces along a majority of the length of the distraction maintenance device.
27. The system of claim 1 , wherein the lower surface is covered by distal sloped surfaces along a majority of the length of the distraction maintenance device.
28. 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;
a mid-longitudinal axis extending through the trailing end and the insertion end, and a length extending between the trailing end and the insertion end;
a first planar side and a second planar side, each of the first and second planar sides intersecting portions of the upper surface, the lower surface, the trailing end, and the insertion end, the first and second planar sides extending along a substantial majority of the length of the distraction maintenance device;
at least one of the upper surface and the lower surface includes a plurality of bone engaging ratchets, each ratchet of the plurality of bone engaging ratchets having a distal sloped surface facing the insertion end and a proximal sloped surface facing the trailing end, the distal sloped surface adapted to facilitate insertion of the distraction maintenance device between the upper and lower vertebral bodies, the proximal sloped surface adapted to resist expulsion of the distraction maintenance device from between the upper and lower vertebral bodies, the distal sloped surface and the proximal sloped surface intersecting one another.
29. The distraction maintenance device of claim 28 , wherein the curvilinear insertion end includes a convex arc between the upper surface and the lower surface.
30. The distraction maintenance device of claim 28 , further comprising opposite sidewalls between the upper surface and the lower surface.
31. The distraction maintenance device of claim 30 , wherein the opposite sidewalls are substantially planar.
32. The distraction maintenance device of claim 28 , wherein the plurality of bone engaging ratchets are oriented to resist proximal migration of the distraction maintenance device more than the plurality of bone engaging ratchets resist distal migration of the distraction maintenance device.
33. The distraction maintenance device of claim 28 , wherein the distal sloped surface is longer than the proximal sloped surface.
34. The distraction maintenance device of claim 28 , wherein, for each of the plurality of bone engaging ratchets, the distal sloped surface and the proximal sloped surface meet at an obtuse angle.
35. The distraction maintenance device of claim 28 , wherein, for each of the plurality of bone engaging ratchets, the distal sloped surface and the proximal sloped surface meet at an acute angle.
36. The distraction maintenance device of claim 28 , wherein the distraction maintenance device has a generally rectangular cross section transverse to the mid-longitudinal axis along at least a portion of the length of the distraction maintenance device.
37. The distraction maintenance device of claim 28 ,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.
38. The distraction maintenance device of claim 28 , wherein, for each ratchet of the plurality of bone-engaging ratchets, the intersection between the distal sloped surface and the proximal sloped surface forms a peak.
39. The distraction maintenance device of claim 28 , wherein the distal sloped surface of a first of the plurality of bone-engaging ratchets intersects the proximal sloped surface of a second of the plurality of bone-engaging ratchets.
40. The distraction maintenance device of claim 28 , wherein each of the plurality of bone-engaging ratchets has a generally triangular shape in a place parallel to the mid-longitudinal axis and passing through the upper and lower surfaces.
41. The distraction maintenance device of claim 28 , further comprising a slot formed in the trailing end.
42. The distraction maintenance device of claim 41 , further comprising a circular hole positioned in the slot.
43. The distraction maintenance device of claim 28 , further comprising at least three bone-engaging ratchets of the plurality of'bone engaging ratchets.
44. The distraction maintenance device of claim 28 , further comprising at least four bone-engaging ratchets of the plurality of bone engaging ratchets.
45. The distraction maintenance device of claim 28 , wherein the upper surface is covered by distal sloped surfaces along a majority of the length of the distraction maintenance device.
46. The distraction maintenance device of claim 28 , wherein the lower surface is covered by distal sloped surfaces along a majority of the length of the distraction maintenance device.
47. 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, a trailing end, a mid-longitudinal axis extending through the trailing end and the insertion end, a length extending between the trailing end and the insertion end, a plurality of non-threaded ratchets on the upper and lower surfaces, a first planar side, and a second planar side, each of the first and second planar sides intersecting portions of the upper surface, the lower surface, the trailing end, and the insertion end, the first and second'planar sides extending along a substantial majority of the length of the distraction maintenance device, 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.
48. The system of claim 47 , wherein the distal end of the first distractor is tapered for wedging between the upper vertebral body and the lower vertebral body.
49. The system of claim 47 , wherein the distal end of the first distractor is bullet-shaped.
50. The system of claim 47 , wherein the distal end of the first distractor is substantially the same shape as the insertion end of the distraction maintenance device.
51. The system of claim 47 , wherein the first thickness and the second thickness are diameters.
52. The system of claim 47 , wherein each of the plurality of non-threaded ratchets includes a distal facet facing the insertion end and a proximal facet facing the trailing end, and the plurality of non-threaded ratchets are oriented to resist proximal migration of the distraction maintenance device more than the surface irregularities resist distal migration of the distraction maintenance device.
53. The system of claim 52 , wherein, for each of the plurality of non-threaded ratchets, the distal facet is sloped to facilitate insertion of the distraction maintenance device between the upper and lower vertebral bodies and the proximal facet is sloped to resist expulsion of the distraction maintenance device from between the upper and lower vertebral bodies.
54. The system of claim 53 , wherein, for each of the plurality of non-threaded ratchets, the distal facet and the proximal facet intersect one another.
55. The system of claim 54 , wherein, for each ratchet of the plurality of non-threaded ratchets, the intersection between the distal facet and the proximal facet forms a peak.
56. The system of claim 53 , wherein the distal facet of a first of the plurality of non-threaded ratchets intersects the proximal facet of a second of the plurality of non-threaded ratchets.
57. The system of claim 53 , wherein each of the plurality of non-threaded ratchets has a generally triangular shape in a place parallel to the mid-longitudinal axis and passing through the upper and lower surfaces.
58. The system of claim 53 , further comprising at least three non-threaded ratchets of the plurality of non-threaded ratchets on one of the upper and lower surfaces of the distraction maintenance device.
59. The system of claim 53 , further comprising at least four non-threaded ratchets of the plurality of non-threaded ratchets on one of the upper and lower surfaces of the distraction maintenance device.
60. The system of claim 53 , wherein the upper surface of the distraction maintenance device is covered by distal facets along a majority of the length of the distraction maintenance device.
61. The system of claim 53 , wherein the lower surface of the distraction maintenance device is covered by distal facets along a majority of the length of the distraction maintenance device.
62. The system of claim 47 , wherein the distraction maintenance device has a generally rectangular cross section transverse to the mid-longitudinal axis along at least a portion of the length of the distraction maintenance device.
63. The system of claim 47 , further comprising an inserter adapted to cooperatively engage the distraction maintenance device.
64. The system of claim 47 , 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.
65. The system of claim 47 , 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.
66. The system of claim 47 , 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.
67. The system of claim 66 , wherein the tissue removal device is a rotating cutter.
68. The system of claim 47 , further comprising a distractor puller for removing the distractors from between the upper vertebral body and the lower body.
69. The system of claim 47 , further comprising a slot formed in the trailing end of the distraction maintenance device.
70. The system of claim 69 , further comprising a circular hole positioned in the slot.