SPINAL IMPLANTS AND METHODS

• US 20080177306A1
• Filed: 01/25/2008
• Published: 07/24/2008
• Est. Priority Date: 10/25/2004
• Status: Active Grant

• Current Assignee: Zimmer Biomet Spine, Inc. (Zimvie Incorporated)
• Original Assignee: LANX Incorporated (Zimmer Biomet Holdings, Inc.)
• Inventors: Lins, Robert, Thramann, Jeffery, Lamborne, Andrew, Fulton, Michael, Binder, Lawrence, Ziemek, Terry
• Granted Patent: US 9,055,981 B2
• Time in Patent Office: Days
• US Class Current: 606/246
• 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 17/7065 Devices with changeable shape, e.g. collapsible or having retractable arms to aid implantation; Tools therefor
• CPC Class Codes: A61B 17/7067 Devices bearing against one or more spinous processes and also attached to another part of the spine; Tools therefor

Abstract

The present invention provides a spinal implant for placement between adjacent processes of the human spine. In some embodiments the spinal implant includes a spacer and one or more retention members. In some embodiments, the retention members are fixed relative to the spacer and in other embodiments the retention members are deployable from a first or compact or stowed position to a second or expanded or deployed position. In some embodiments the spacer is expandable from a first size to a second size. In some embodiments the spacer has a tapered body.

Claims

1. A spinal implant for placement between adjacent processes of the human spine comprising:

a spacer having a first end, a second end, and a spacer axis extending, therebetween, the spacer having an outer surface spaced from the spacer axis; and

at least one deployable retention member moveable from a first position in which the retention member is positioned generally at or inwardly of the outer surface to a second position in which the retention member projects outwardly beyond, the outer surface.

2. The spinal implant of claim 1 wherein the retention member comprises a loop.

3. The spinal implant of claim 1 wherein the retention member is contained within the spacer in the first position.

4. The spinal implant of claim 1 wherein the spacer includes an interior cavity receiving the retention member and an actuator mounted to the spacer, the actuator being responsive, to rotation to translate relative to the spacer and move the retention member from the first position to the second position.

5. The spinal implant of claim 1 wherein the retention member is biased into a curved shape and wherein the retention member is elastically straightened in the first position and recovers to its curved shape in the second position.

6. The spinal implant of claim 1 wherein the spacer includes a passageway at least partway through the spacer and at least a portion of the retention member moves within the passageway from the first position to the second position.

7. The spinal implant of claim 6 further comprising a fixed extension projecting outwardly beyond the outer surface adjacent the first end, an interior-cavity that houses the retention member, and an actuator screw threadably engaged with the spacer, the actuator screw being responsive to rotation to translate relative to the spacer and move the retention member from the first position to the second position, the retention member projecting outwardly beyond the outer surface adjacent the second end.

8. The spinal implant of claim 1 wherein the spacer includes a curved passageway and at least a portion of the retention member moves through the passageway from the first position to the second position causing the portion to curve as it moves to the second position.

9. The spinal implant of claim 1 further comprising at least one end piece spaced further from the spacer in the first position and spaced nearer to then spacer in the second position, the end piece including a passageway receiving at least a portion of the retention member for translation therethrough.

10. The spinal implant of claim 9 further comprising a threaded shaft connecting the spacer to the end piece, the shaft being responsive to rotation to move the spacer and shaft nearer to one another and thereby force the retention member to project out of the end piece and away from the spacer axis.

11. The spinal implant of claim 1 wherein the spacer comprises a passageway extending through it, the spinal implant further comprising a core receivable in the passageway, the retention member being mounted to the core.

12. The spinal implant of claim 11 wherein the retention member is mounted to the core in generally outwardly oriented relationship transverse to the spacer axis, the retention member being elastically moveable to a position generally parallel to the spacer axis for insertion with the core through the passageway.

13. The spinal implant of claim 12 further comprising a tube removably received around the core and retention member temporarily maintaining the retention member generally parallel to the spacer axis.

14. The spinal implant of claim 11 wherein the retention member comprises a plurality of strands moveable from an orientation along the sides of the spacer to a pattern of loops extending outwardly transverse to the spacer axis.

15. The spinal implant of claim 14 wherein the strands comprise first and second strand ends and the first strand ends are mounted for translation nearer to the second strand ends, the strands being responsive to translation of the first strand ends nearer to the second strand ends to project outwardly transverse to the spacer axis and form a pattern of loops.

16. The spinal implant of claim 1 wherein the spacer is deformable from a first dimension transverse to the spacer axis to a second, smaller, dimension transverse to the spacer axis to facilitate insertion between adjacent processes prior to inserting the core.

17. The spinal implant of claim 16 wherein the spacer is responsive to stretching transverse to the spacer axis to deform from the first dimension to the second dimension.

18. The spinal implant of claim 1 wherein the spacer comprises a passageway extending through it generally parallel to the spacer axis and the retention member comprises a strip of material having a nominally curved shape, the retention member being withdrawn into the passageway at least a first end of the passageway in the first position and the retention member extending from the first end of the passageway in the second position.

19. The spinal implant of claim 1 wherein the spacer comprises a passageway extending through it and the retention member comprises a strip of material having a nominally curved shape, the retention member being movable from the first position to the second position by inserting the retention member through the passageway, the retention member being responsive to exiting the passageway to return to its nominally curved shape.

20. A spinal implant for placement between adjacent processes of the human spine comprising:

a spacer having a first end, a second end, a spacer axis extending therebetween, a passageway through the spacer having a first passageway end and a second passageway end, and an outer surface spaced from the spacer axis; and

at least one deployable retention member comprising an elongated, member preformed into a nominal shape able to extend outwardly from the passageway transverse to the spacer axis beyond the outer surface, the retention member being receivable through the passageway from the first passageway end to the second passageway end, the retention member being responsive to exiting the second passageway end to recover its nominal shape and extend outwardly beyond the outer surface.

21. A spinal implant for placement between adjacent processes of the human spine comprising:

a spacer having a first end, a second end, a spacer axis extending therebetween, and an outer surface spaced from the spacer axis; and

at least one deployable retention member mounted adjacent the first end and being expandable from a first position in which the retention member is positioned generally at or inwardly of the outer surface to a second position in which the retention member projects radially outwardly beyond the outer surface.

22. The spinal implant of claim 21 wherein the retention member comprises a coil having a dimension transverse to the spacer axis, the coil being relatively tightly wound in the first position and the coil being relatively loosely wound in the second position, the dimension of the coil transverse to the spacer axis being greater in the second position than in the first position.

23. The spinal implant of claim 21 wherein the retention member comprises an arm mounted for rotation from the first position in which the arm is closer to the spacer axis to the second position in which the arm is further from the spacer axis.

24. The spinal implant of claim 23 wherein the spacer comprises a generally cylindrical body and the retention member comprises an elongated member mounted to the body for rotation about a rotation axis generally parallel to the spacer axis, the retention member having a transverse portion extending transverse to the rotation axis, the retention member being rotatable from a first position in which the transverse portion is nearer the spacer axis and a second position in which the transverse portion is further from the spacer axis.

25. The spinal implant of claim 21 wherein the retention member comprises a first end piece mounted for rotation about a first rotation axis offset from the spacer axis, the first end piece being rotatable about the first rotation axis from a first position nearer the spacer axis to a second position further from the spacer axis.

26. The spinal implant of claim 25 further comprising a second end piece mounted for rotation about a second rotation axis offset from both the spacer axis and the first rotation axis, the second end piece being rotatable about the second rotation axis from a first position nearer the spacer axis to a second position further from the spacer axis.

27. The spinal implant of claim 26 further comprising third and fourth end pieces, the third end piece being mounted for rotation with the first end piece and the fourth end-piece being mounted for rotation with the second end piece, the first and second end pieces being mounted adjacent the first end of the spacer and the second and fourth end pieces being mounted adjacent the second end of the spacer.

28. The spinal implant of claim 25 further comprising a shaft and a second end piece, the first and second end pieces being mounted on the shaft for rotation together with the shaft about the rotation axis, at least the first end piece being mounted for slipping relative to the shaft above a predetermined torque level such that the second end piece can continue to rotate with the shaft while the second end piece remains stationary if the first end piece becomes stuck.

29. The spinal implant of claim 21 wherein the retention member comprises a first end piece mounted for rotation about a first rotation axis transverse to the spacer axis.

30. The spinal implant of claim 29 wherein the end piece is elongated and extends generally parallel to the spacer axis in the first position and extends generally transverse to the spacer axis in the second position.

31. The spinal implant of claim 30 wherein the end piece tapers from a first dimension adjacent the spacer to a second, smaller, dimension spaced from the spacer.

32. The spinal implant of claim 30 further comprising a fixed extension adjacent the second end, the fixed extension extending away from the spacer-axis beyond the outer surface, and an actuator operably connected to the first end piece and being operable from the second end, the actuator being responsive to actuation to rotate the first end piece about the first rotation axis.

33. The spinal implant of claim 29 further comprising a second end piece mounted for rotation about a second rotation axis transverse to the spacer axis and the first rotation axis.

34. The spinal implant of claim 33 further comprising a shaft mounted to the spacer for relative rotation, the shaft being operably connected to the first and second end pieces, the shaft being, responsive to rotation to simultaneously rotate the first, end piece about the first rotation axis and the second end piece about the second rotation axis.

35. The spinal implant of claim 33 further comprising a third end piece mounted for rotation about a third rotation axis transverse to the spacer axis and a fourth end piece mounted for rotation about a fourth rotation axis transverse to the spacer axis, the first and second end pieces being mounted adjacent the first end of the spacer and the third and fourth end pieces being mounted adjacent the second end of the spacer, the first and second end pieces being rotatable to project radially outwardly from the spacer axis in different directions relative to one another and the third and fourth end pieces being rotatable to project radially outwardly from the spacer axis in different directions relative to one another.

36. The spinal implant of claim 21 wherein the spacer comprises a tubular member elastically compressible toward the spacer axis and the retention member comprises an integral arm extending away from the spacer transverse to the spacer axis in the second position, the arm being elastically straightenable to assume the first position.

37. A spinal implant for placement between adjacent processes of the human spine comprising a spacer having a first end, a second end, and a spacer axis extending therebetween, the spacer comprising a hollow tubular structure having a tube wall with inner and outer surfaces spaced from the spacer axis and being open at the first and second ends, the tube wall having a plurality of holes penetrating the tube wall in a radial array near each of the first and second ends.

38. A spinal implant for placement between adjacent processes of the human spine comprising a spacer having a first end, a second end, and a spacer axis extending therebetween, the spacer comprising a monolithic structure having an outer surface spaced from the spacer axis, the spacer having at least one fastener receiving passageway communicating from the first end to the outer surface transverse to the spacer axis to receive a fastener to attach the spacer to a process.

39. A spinal implant for placement between adjacent processes of the human spine comprising a spacer having a first end, a second end, and a spacer axis extending therebetween, the spacer comprising a flange extending outwardly transverse to the spacer axis adjacent the first end to extend alongside a process, the flange including a fastener receiving hole extending through the flange to receive a fastener to attach the flange tog the process.

40. A spinal implant for placement between adjacent processes of the human spine, the spinal implant comprising:

a base having an elongated portion having a base axis and a transverse portion extending generally transversely away from the base axis; and

a spacer engageable with the elongated portion in axial translating relationship along the base axis.

41. The spinal implant of claim 40 wherein the spacer tapers from a first smaller diameter nearer the transverse portion to a second larger diameter further from the transverse portion, the spacer being moveable from a first position further from the transverse portion to a second position nearer the transverse portion.

42. A spinal implant for placement between adjacent processes of the human spine comprising:

a spacer having a first end, a second end, and a spacer axis extending therebetween, the spacer having an outer surface spaced from the spacer axis; and

means for translating the first end nearer to the second end and causing the outer surface to move further away from the spacer axis.

43. The spinal implant of claim 42 further comprising at least one, deployable retention member moveable from a first position in which the retention member is positioned generally at or inwardly of the outer surface to a second position in which the retention member projects outwardly beyond the outer surface.

44. The spinal implant of claim 42 wherein the spacer comprises a split body and the outer surface comprises a superior surface and an inferior surface, the spinal implant further comprising a wedge member moveable between the superior surface and the inferior surface to move the superior and inferior surfaces further away from the spacer axis.

45. The spinal implant of claim 42 wherein the spacer comprises a resilient material and a passageway extends through the spacer, the spinal implant further comprising a base;

positioned at the first end of the spacer and a plate extending transverse to the spacer axis beyond the outer surface at the second end, a shaft connecting the base and plate through the passageway in relative translating relationship, the plate and base being movable between a first position in which they are relatively further from one another and a second position in which they are relatively nearer one another, the plate and base compressing the spacer axially and expanding the spacer transverse to the spacer axis when the plate and base are moved to the second position.

46. A spinal implant for placement between adjacent processes of the human spine comprising:

a spacer having a first end, a second end, and a spacer axis extending therebetween, the spacer comprising a hollow tubular structure having a tube wall with inner and outer surfaces spaced from the spacer axis, the inner surface defining an axial passageway; and

means for expanding the tube wall to move the outer surface further from the spacer axis.

47. The spinal implant of claim 46 wherein the tube wall is discontinuous and defines first and second edges, the spinal implant further comprising at least one tapered insert axial translatable within the axial passageway from a first position in which the outer surface is spaced a first distance from the spacer axis and a second position in which the outer surface is spaced a second, greater, distance from the spacer axis.

48. The spinal implant of claim 46 wherein the tube wall comprises a coiled sheet, the tube wall being moveable between a first position in which the sheet is relatively tightly coiled and a second position in which the sheet is relatively loosely coiled.

49. The spinal implant of claim 48 wherein the coiled sheet comprises first and second coiled sheet ends, each end defining a hook, the hooks engaging when the sheet is uncoiled to limit the expansion of the coiled sheet.

50. The spinal implant of claim 48 wherein the coiled sheet comprises at least one opening through the tube wall and the coiled sheet comprises at least one tab extending away from the coiled sheet transverse to the spacer axis and being engageable with the opening to limit the expansion of the coiled sheet.

51. The spinal implant of claim 50 wherein the coiled sheet comprises a plurality of openings through the tube wall, the tab being selectively engageable with each of the plurality of openings to limit the expansion of the coiled sheet to different sizes depending on which of the plurality of openings is engaged.

52. A spinal implant for placement between adjacent processes of the human spine comprising:

a spacer having a first end, a second end, and a spacer axis extending therebetween, the spacer comprising a wedge shaped body tapering from a first dimension transverse to the spacer axis nearer the first end to a second, smaller, dimension transverse to the spacer axis further from the first end;

a first extension projecting outwardly beyond the outer surface adjacent the first end; and

a second extension engageable with the spacer in axial translating relationship relative to the first extension, the first and second extensions defining a midpoint between them, the first and second extensions being moveable from a first position in which the extensions are spaced a first axial distance apart and in which the extensions define a first midpoint between them, and a second position in which the extensions are spaced a second, smaller, axial distance apart and in which the extensions define a second midpoint between them, the dimension of the spacer body perpendicular to the spacer axis at the first midpoint being smaller than the dimension of the spacer body perpendicular to the spacer axis at the second midpoint.

53. The spinal implant of claim 52 wherein the second extension comprises a plate-like body with a through opening able to receive the spacer body.

54. The spinal implant of claim 53 further comprising a locking mechanism for locking the relative axial position of the first and second extensions.

55. The spinal implant of claim 54 wherein the locking mechanism comprises a ratchet mechanism.

56. The spinal implant of claim 54 wherein the locking mechanism comprises a screw.

57. The spinal implant of claim 52 wherein the first extension is fixed to the spacer body and the second extension further comprises first and second tabs, the spacer body being receivable between the first and second tabs.

58. A spinal implant for placement between adjacent processes of the human spine comprising:

a first part having a first end, a second end, and at least one first lateral wall coupled to the first end;

the at least one first lateral wall adapted to extend along a side of one of the processes;

the second end adapted to reside in an inter process space between the processes;

a second part having a third end, a fourth end, and at least one second lateral wall coupled to the third end and adapted to extend along a side of one of the processes;

the fourth end adapted to reside in the inter process space proximate the second end;

at least one guidewire channel extending through the first part and the second part; and

at least one guidewire extending through the at least one guidewire channel to couple the first part and the second part together in an aligned relationship, wherein the spacer at least one of distracts or maintains the distraction between the superior process and inferior process.

59. The spinal implant of claim 58, wherein the second end comprises at least one mating channel and the fourth end comprises at least one mating protrusion such that the at least one mating channel and the at least one mating protrusion engage.

60. The spinal implant of claim 58, wherein the at least one guidewire channel comprises a plurality of guidewire channels and the guidewire has a first end proximate the at least one second lateral wall, a second end proximate the at least one second lateral wall, and a main body in the plurality of guidewire channels such that the guidewire loops around the at least one first lateral wall.

61. The spinal implant of claim 58, further comprising a bore extending through the second end and the fourth end and a connector residing in the bore.

62. The spinal implant of claim 61, wherein the connector is a set screw threadably connected to the bore.

63. The spinal implant of claim 58, wherein the at least one guidewire has a first end terminated adjacent to the at least one first lateral wall and a second end terminated adjacent to the at least one second lateral wall.

64. The spinal implant of claim 63, wherein the guide wire ends are each terminated with a device selected from the group of terminating devices consisting of a crimp, a tie, set screw, and a cable lock.

65. The spinal implant of claim 58, further comprising at least one first bore in the at least one first lateral wall and at least one second bore in the at least one second lateral wall, and at least one flexible biocompatible material extending from the at least one first bore to the at least one second bore about at least one of the processes.

66. A method of distracting a vertebral segment comprising a superior vertebral body having a superior process and an inferior vertebral body having an inferior process, the method comprising the steps of:

providing an access to an inter process space;

inserting a first part of an inter process spacer through the access;

inserting a second part of the inter process spacer through the access using a guidewire extending from the first part through the access to the second part;

compressing the first part and the second part together; and

locking the first part and the second part compressed together.

67. The method of claim 66, further comprising the step of distracting the superior vertebral body and the inferior vertebral body.

68. The method of claim 67, wherein the step of distracting and the step inserting a first part occur substantially simultaneously.

69. A spinal implant for placement between adjacent processes of the human spine comprising:

a first seat having a process contacting surface;

a distraction post connected to the first seat;

a second seat having a process contacting surface, the second seat including an attachment tab having a through opening receiving the distraction post in axial translating relationship, the first and second seats being moveable from a first position in which the process contacting surfaces are relatively closer together to a second position in which the process contacting surfaces are relatively further apart; and

a locking mechanism for locking the first and second seat relative to one another.

70. The spinal implant of claim 69 wherein the process contacting surface of the first seat is coplanar with the process contacting surface of the second seat in the first position.

71. The spinal implant of claim 70 wherein one of the first and second seats includes a plurality of process contacting surfaces spaced apart with a gap between them, the process contacting surface of the other of the first and second seats being receivable in the gap so that at least one process contacting surface of the first seat is coplanar with at least one process contacting surface of the second seat.

72. The spinal implant of claim 69 wherein at least one of the first and second seats further comprises walls extending away from the process contacting surface to surround a portion of a process.