Method for inserting and deploying an expandable interbody spinal fusion implant

• US 20040093084A1
• Filed: 11/06/2003
• Published: 05/13/2004
• Est. Priority Date: 02/04/2001
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Michelson, Gary K.
• Granted Patent: US 7,655,027 B2
• Time in Patent Office: Days
• US Class Current: 623/17.11
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• CPC Class Codes: A61F 2/4601 for introducing bone substitute, for implanting bone graft implants or for compacting them in the bone cavity
• CPC Class Codes: A61F 2/4603 for insertion or extraction of endoprosthetic joints or of accessories thereof
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2/4637 for connecting or disconnecting two parts of a prosthesis
• CPC Class Codes: A61F 2002/30143 hexagonal
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30235 tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30428 made by inserting a protrusion into a slot
• CPC Class Codes: A61F 2002/30487 Circumferential cooperating grooves and beads on cooperating lateral surfaces of a mainly longitudinal connection
• CPC Class Codes: A61F 2002/30574 with an integral complete or partial collar or flange
• CPC Class Codes: A61F 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30777 Oblong apertures
• CPC Class Codes: A61F 2002/30787 inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30975 made of two halves
• CPC Class Codes: A61F 2002/4627 with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument
• CPC Class Codes: A61F 2220/0025 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2230/0017 Angular shapes
• CPC Class Codes: A61F 2230/0069 cylindrical

Abstract

Instruments and methods for inserting and expanding interbody spinal fusion implants having an expandable height.

Claims

1. A method for expanding an expandable spinal implant having an expander adapted to increase the height of the implant, the method comprising the steps oil:

providing an implant holder having a passage therethrough adapted to receive an expander driver;

attaching the implant holder to the implant;

inserting the expander driver having a shaft through the passage of the implant holder to engage the expander of the implant; and

rotating the expander driver to expand the expandable implant.

2. The method of claim 1, wherein the providing step includes the step of providing the implant holder having extensions having an exterior surface adapted to engage the implant, the extensions being adapted to move between a disengaged position with the extensions at a first distance from one another and an engaged position with the extensions at a second distance from one another, the second distance being larger than the first distance.

3. The method of claim 2, wherein the providing step includes the step of providing the implant holder with extensions having an interior surface oriented toward the passage of the implant holder, the extensions being adapted to move away from the longitudinal axis of the implant holder to the engaged position by an outward force applied to the interior surface.

4. The method of claim 3, wherein the attaching step includes the step of applying an outward force to the interior surface of the extensions to engage the extensions with the implant.

5. The method of claim 3, wherein the providing step includes the step of providing the implant holder having a shaft adapted to move along at least a portion of the length of the passage of the implant holder, the distal end of the shaft being sized and shaped to cooperatively engage the interior surface of the extensions of the implant holder to spread apart the extensions to lock the implant holder to the implant.

6. The method of claim 2, wherein the providing step includes the step of providing the implant holder with extensions adapted to be moved toward the longitudinal axis of the implant holder by an inward force applied to the exterior surface to permit the extensions to pass into the trailing end of the implant and to permit the extensions to-engage the implant after the inward force is-removed.

7. The method of claim 6, further comprising the step of applying an inward force to the exterior surface of the extensions to permit the extensions to pass into the trailing end of the implant.

8. The method of claim 7, wherein the attaching step includes the step of removing the inward force to the exterior surface of the extensions to permit the extensions to engage the implant.

9. The method of claim 2, wherein the providing step includes the step of providing the implant holder with extensions having at least one projection adapted to cooperatively engage at least a portion of the trailing end of the implant.

10. The method of claim 1, further comprising the step of performing the spinal implant surgery from a position posterior to the transverse processes of the vertebral bodies.

11. The method of claim 1, further comprising the step of performing the spinal implant surgery from a position anterior to the transverse processes of the vertebral bodies.

12. The method of claim 1, further comprising the steps of performing the procedure on both sides of the spinal midline of the spine and inserting two implants into the spine, each of the implants having a width less than half the width of the disc space.

13. The method of claim 1, further comprising the step of positioning into a disc space between adjacent vertebral bodies a guard having an extension for insertion into the disc space previously occupied by the disc and for bearing against end plates of adjacent vertebral bodies of the spine to generally restore the spacing of the disc space between the adjacent vertebral bodies.

14. The method of claim 13, further comprising the step of forming, through the guard, an implantation space across at least the height of the disc space.

15. The method of claim 14, further comprising the step of inserting the implant into the implantation space.

16. The method of claim 15, wherein the step of inserting the implant includes the step of using the implant holder to insert the implant into the implantation space through the guard.

17. The method of claim 16, further comprising the step of removing the implant holder from the guard after the step of using the implant holder to insert the implant.

18. The method of claim 16, further comprising the step of removing the implant holder and the guard together after the step of using the implant holder to insert the implant.

19. The method of claim 13, wherein the positioning step includes the step of positioning a guard having multiple extensions for insertion into the disc space and for bearing against end plates of the two adjacent vertebrae.

20. The method of claim 13, wherein the positioning step includes the step of spacing the adjacent vertebrae apart.

21. The method of claim 13, wherein the positioning step includes the step of inducing angulation to the adjacent vertebrae relative to one another.

22. The method of claim 13, wherein the positioning step includes the guard having upper and lower members adapted for movable engagement with one another.

23. The method of claim 22, wherein the positioning step includes the step of pivoting the upper and lower members of the guard to induce angulation of the adjacent vertebral bodies.

24. The method of claim 21, wherein the inducing angulation step includes the step of restoring lordosis to the spine.

25. The method of claim 21, wherein the inducing angulation step includes the step of restoring kyphosis to the spine.

26. The method of claim 13, further comprising the step of engaging the guard into the adjacent vertebrae.

27. The method of claim 15, further comprising the step of removing the guard after the inserting step.

28. The method of claim 14, wherein the forming step includes the step of forming the implantation space with a bone removal instrument.

29. The method of claim 28, wherein the forming step includes the step of one of milling, drilling, reaming, chiseling, and trephining the implantation space.

30. The method of claim 1 further comprising the step of inserting a spinal distractor into a disc space between adjacent vertebral bodies to provide for proper spacing of the disc space between the vertebral bodies.

31. The method of claim 30, wherein the step of inserting a spinal distractor includes the step of inducing angulation to the adjacent vertebrae.

32. The method of claim 30, further comprising the step of removing the spinal distractor prior to forming an implantation space.

33. The method of claim 1, further comprising the step of inserting the implant into an implantation space.

34. The method of claim 33, wherein the step of inserting includes the step of screwing the implant into the implantation space.

35. The method of claim 33, wherein the step of inserting includes the step of pushing the implant into the implantation space.

36. The method of claim 33, wherein the step of inserting the implant includes the step of driving the implant into the implantation space with the implant holder.

37. The method of claim 33, wherein the step of inserting the implant includes the step of removing the implant from the implantation space with the implant holder.

38. The method of claim 33, further comprising the step of removing the implant holder from the implant after the step of inserting the implant.

39. The method of claim 1, further comprising the step of loading the implant with fusion promoting substance.

40. The method of claim 39, wherein the step of loading includes the step of compressively loading the implant with fusion promoting substance.

41. The method of claim 39, wherein the step of compressively loading includes pressing the fusion promoting substance into the implant with one of a tamp, press, and piston.

42. The method of claim 39, further comprising the step of inserting the implant into the spine, wherein at least a portion of the loading step occurs after the step of inserting the implant.

43. The method of claim 39, wherein the loading step includes loading the implant with the fusion promoting substance being selected from one of bone, bone derived products, demineralized bone matrix, ossifying proteins bone morphogenetic protein, hydroxyapatite, and genes coding for the production of bone.

44. The method of claim 39, further comprising the step of retaining the fusion promoting substance within the implant after the step of loading.

45. The method of claim 44, wherein the step of retaining includes the step of attaching a cap to the implant to retain the fusion promoting substance.

46. The method of claim 1, further comprising the step of treating the implant with a fusion promoting substance.

47. The method of claim 1, wherein the implant is in combination with a chemical substance adapted to inhibit scar formation.

48. The method of claim 1, wherein the implant is in combination with an antimicrobial material.

49. The method of claim 1, further comprising the step of inserting the expandable implant into an implantation space in the spine.

50. The method of claim 49, wherein the inserting step includes inserting an implant comprising a fusion promoting substance.

51. The method of claim 49, wherein the inserting step includes inserting an implant comprising a bone ingrowth surface.

52. The method of claim 49, wherein the inserting step includes inserting a spinal implant that is a spinal fusion implant for promoting fusion between adjacent vertebral bodies, the implant having upper and lower surfaces for placement between and in contact with the adjacent vertebral bodies, each of the upper and lower surfaces having at least one opening adapted to permit bone from the adjacent vertebral bodies to grow through the implant.

53. The method of claim 49, wherein the inserting step includes inserting a spinal fusion implant having a hollow between the upper and lower surfaces for holding fusion promoting substances.

54. The method of claim 49, wherein the inserting step includes inserting a spinal fusion implant that is separable into an upper member and a lower member to permit the placement of the expander between the upper and lower members.

55. The method of claim 54, wherein the inserting step includes inserting a spinal fusion implant with the upper and lower members being at least in part arcuate.

56. The method of claim 55, wherein the inserting step includes screwing a threaded spinal fusion implant into an implantation space in the spine.

57. The method of claim 49, wherein the inserting step includes inserting a spinal fusion implant configured for at least in part linear insertion into a prepared implantation space between the adjacent vertebral bodies.

58. The method of claim 49, wherein the inserting step includes inserting a spinal fusion implant having surface projections configured to resist expulsion of the implant from an implantation space into which the implant is adapted to be inserted.

59. The method of claim 49, wherein the inserting step includes the step of inserting an implant having a hollow between the ends that is generally unobstructed by an expander so as to allow for the unimpeded loading of the interior of the implant with a fusion promoting substance.

60. The method of claim 49, wherein the inserting step includes the step of inserting an implant having a trailing end adapted to be engaged to the implant holder.

61. The method of claim 49, wherein the inserting step includes the step of inserting an implant comprised at least in part of one of bone and bone growth promoting material.

62. The method of claim 49, wherein the inserting step includes the step of inserting an implant that is an inert spacer.

63. The method of claim 49, wherein the inserting step includes the step of inserting an implant that is an artificial disc.

64. The method of claim 49, wherein the inserting step includes the step of inserting an implant that is a bone graft.

65. The method of claim 1, wherein the step of inserting the expander driver includes the step of assembling the implant, implant holder, and expander driver together so that the expander driver is in a first locked position relative to the implant holder to prevent rotation of the expander driver relative to the implant holder.

66. The method of claim 65, further comprising the step of partially retracting the expander driver to a second locked position that permits rotation of the expander driver relative to the implant holder so as to allow the expander driver to rotate the expander of the implant.

67. The method of claim 66, further comprising the step of removing the expander driver from the implant and the implant holder.

68. The method of claim 1, further comprising the step of limiting the depth of penetration of the expander driver into and through the expander of the implant.

69. The method of claim 1, further comprising the step of removing the expander driver from the implant and the implant holder.

70. The method of claim 1, further comprising the step of passing fusion promoting substance through the passage of the implant holder and into the implant.

71. The method of claim 70, further comprising the step of using the expander driver to move the fusion promoting substance through the passage of the implant holder and into the interior of the implant.

72. The method of claim 71, further comprising the step of advancing the expander driver through the fusion promoting substance in the implant until the expander driver reaches and is advanced into engagement with the expander of the implant.

73. The method of claim 1, wherein the step of rotating the expander driver includes the step of expanding the leading end of the implant to increase the maximum implant height which is proximate the leading end of the implant.

74. The method of claim 1, wherein the step of rotating the expander driver includes the step of expanding the trailing end of the implant to increase the maximum implant height which is proximate the trailing end of the implant.

75. The method of claim 1, wherein the step of rotating the expander driver includes the step of expanding both the leading end and the trailing end of the implant to increase the maximum implant height proximate both the leading end and the trailing end of the implant.

76. The method of claim 1 wherein the step of rotating the expander driver includes the step of expanding the implant to induce angulation to the adjacent vertebral bodies.

77. The method of claim 1, wherein the attaching step includes the step of locking the implant holder to the implant.

78. The method of claim 77, further comprising the step of unlocking the implant holder from the implant.

79. The method of claim 78, removing the implant holder from the implant.

80. A method for loading a spinal implant with fusion promoting substances, the method comprising the steps of:

providing an implant holder having a passage therethrough;

attaching the implant holder to the implant; and

passing fusion promoting substances through the passage of the implant holder into the implant.

81. A method for inserting an interbody spinal implant into an implantation space, the method comprising the steps of:

providing an implant holder having a body having a distal end, the implant holder having extensions extending from the distal end of the body, the extensions having an exterior surface, the extensions being adapted to be moved toward one another by an inward force applied to the extensions to permit the extensions of the implant holder to pass into the trailing end of the implant and for the exterior surface to cooperatively engage the implant after the inward force is removed;

passing the extensions of the implant holder into the trailing end of the implant; and

cooperatively engaging the exterior surface of the extensions of the implant holder to the implant.