Apparatus for inserting spinal implants

• US 6,270,498 B1
• Filed: 06/07/1995
• Issued: 08/07/2001
• Est. Priority Date: 06/13/1988
• Status: Expired due to Term

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Gary K. Michelson
• Inventors: Michelson, Gary Karlin
• Primary Examiner(s): Brown, Michael A.
• Application Number:
  US08/482,162
• Time in Patent Office: 2,253 Days
• Field of Search: 606/60, 606/61, 606/72, 623/16, 623/17
• US Class Current: 606/914
• 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 17/32 Surgical cutting instruments A61B18/042 takes precedence; suture cutters A61B17/0467; instruments for ligaturing or cutting A61B17/128; instruments for rupturing the amniotic membrane A61B17/4208; specially adapted knives for eye surgery A61F9/0133
• CPC Class Codes: A61B 17/3468 for implanting or removing devices, e.g. prostheses, implants, seeds, wires devices for implanting seeds A61M37/0069
• CPC Class Codes: A61B 17/8888 at its central region
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61B 2017/922 Devices for impaction, impact element
• CPC Class Codes: A61B 2090/036 abutting on tissue or skin
• CPC Class Codes: A61F 2/30744 End caps, e.g. for closing an endoprosthetic cavity
• 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 2/446 having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones
• CPC Class Codes: A61F 2/4603 for insertion or extraction of endoprosthetic joints or of accessories thereof
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• 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 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30426 Bayonet coupling
• 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 2002/30797 : internally-threaded
• 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 2002/4619 : for extraction
• 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 2002/4629 : connected to the endoprosthesis or implant via a threaded connection
• CPC Class Codes: A61F 2002/4649 : Bone graft or bone dowel harvest sites
• CPC Class Codes: A61F 2002/4681 : by applying mechanical shocks, e.g. by hammering
• CPC Class Codes: A61F 2002/4687 : Mechanical guides for implantation instruments
• 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

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. Apparatus and a method of inserting spinal implants is disclosed in which an intervertebral space is first distracted to restore the normal angular relationship of the vertebrae adjacent to that disc space. An extended outer sleeve having extended portions capable of maintaining the vertebrae distracted in their normal angular relationship 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. Apparatus for preparing a surgical implantation site in the spine for implantation of an interbody spinal implant at least in part into a disc space between two adjacent vertebral bodies, said apparatus comprising a hollow generally tubular member having a proximal end, distal end, and at least a first disc penetrating extension extending from said distal end for insertion into the disc space between two adjacent vertebral bodies, said first disc penetrating extension being oriented in a fixed position relative to a mid-longitudinal axis through said tubular member and having a portion for bearing against each of the adjacent endplates of the adjacent vertebral bodies, said portion of said first disc penetrating extension having opposed upper and lower surfaces adapted to bear against each of the adjacent vertebral bodies from within the disc space to align the adjacent vertebrae.

2. The apparatus of claim 1 in which said hollow tubular member comprises a second disc penetrating extension.

3. The apparatus of claim 2 in which said first and second disc penetrating extensions are diametrically opposed to each other.

4. The apparatus of claim 1, in which said first disc penetrating extension has a tapered leading end to facilitate placement of said first disc penetrating extension into the disc space.

5. The apparatus of claim 1, in which said first portion of said disc penetrating extension has a height that is substantially equal to the normal height of the disc space between the two adjacent vertebral bodies.

6. The apparatus of claim 1 in which said upper and lower surfaces are parallel to each other and adapted to distract and align the adjacent vertebral bodies.

7. The apparatus of claim 1, in which said tubular member has a distal end that is contoured to the curvature of the two adjacent vertebral bodies to permit an intimate fit between said hollow tubular member and the two adjacent vertebral bodies.

8. The apparatus of claim 1, further comprising bone engaging means for penetrably engaging the bone of the two adjacent vertebral bodies.

9. The apparatus of claim 1 further including means for preventing over penetration of said first disc penetrating extension.

10. The apparatus of claim 9 in which said preventing means is located proximate the junction of said tubular member and said disc penetrating extension.

11. The apparatus of claim 1 including a removable hollow inner tubular sleeve capable of being inserted into said hollow tubular member.

12. The apparatus of claim 11 in which said inner sleeve has limiting means for limiting the travel of said inner sleeve within said hollow tubular member when said inner sleeve is inserted into said hollow tubular member.

13. The apparatus of claim 1 in which said hollow tubular member has an increased outer dimension portion at its proximal end.

14. The apparatus of claim 1 further comprising means for cooperatively engaging to the proximal end of said tubular member and impaction end member for receiving an impaction force for driving said tubular member into the spine.

15. The apparatus of claim 1 in which said tubular member includes means for cooperatively engaging an extraction device for extracting said tubular member from the disc space.

16. The apparatus of claim 15, in combination with an extraction device adapted to cooperatively engage said tubular member.

17. The apparatus of claim 16, wherein said extraction device includes a sliding weight for imparting an extractive force to said to apparatus.

18. The apparatus of claim 1, in which said disc penetrating extension having a first portion for bearing against the endplates of the adjacent vertebral bodies and a second portion between said first portion and said guard member for bearing against the endplates of the adjacent vertebral bodies, said second portion having a height less than the height of said first portion.

19. The apparatus of claim 1, in which said portion of said disc penetrating extension having a length greater than one half the depth of the disc space measured from the anterior aspect to the posterior aspect of the disc space.

20. The apparatus of claim 1, in which said disc penetrating extension being at least in part coextensive with said external surface of the distal end of said guard member.

21. The apparatus of claim 1, in which said guard member has an external surface at its distal end and said disc penetrating extension being at least in part coextensive with said external surface.

22. The apparatus of claim 21 in which said disc penetrating extension has a tapered leading end to facilitate placement of said disc penetrating extension into the disc space.

23. The apparatus of claim 1 in which said disc penetrating extension has a uniform height along at least a portion of its length.

24. The apparatus of claim 1 in which said disc penetrating extension has opposite surfaces for bearing against the endplates of the adjacent vertebral bodies, said opposite surfaces diverging away from said guard member along at least a portion of their length.

25. The apparatus of claim 1 in which said first disc penetrating extension has a tapered leading end to facilitate placement of said first disc penetrating extension into the disc space.

26. Apparatus for preparing a site in the spine for implantation of a spinal implant at least in part into a disc space between two adjacent vertebral bodies, said apparatus comprising a hollow generally tubular member having at least a first disc penetrating extension for insertion into the disc space between two adjacent vertebral bodies, said first disc penetrating extension having a portion for bearing against each of the adjacent endplates of the adjacent vertebral bodies, said first disc penetrating extension having a height and length sufficient to properly align and distance apart the adjacent vertebral bodies, said height being substantially equal to the normal height of the disc space between the two adjacent vertebral bodies and said length being greater than one half the depth of the disc space measured from the anterior to the posterior aspect of the two adjacent vertebral bodies, said first disc penetrating extension being at least in part in line with one of the side surfaces of said hollow tubular member.

27. The apparatus of claim 26 in which said first disc penetrating extension has a tapered leading end to facilitate placement of said first disc penetrating extension into the disc space.

28. An apparatus for use in human spinal surgery across a disc space between two adjacent vertebral bodies, comprising:

a guard member having an opening for providing protected access to the disc space and the adjacent vertebral bodies, said opening having a maximum height; and

a disc penetrating extension extending from said guard member for insertion into the disc space between the adjacent vertebral bodies, said disc penetrating extension having a portion for bearing against each of the adjacent endplates of the adjacent vertebral bodies, said portion of said disc penetrating extension having an upper surface adapted to contact one of the adjacent endplates of the adjacent vertebral bodies and a lower surface adapted to contact the other of the adjacent endplates of the adjacent vertebral bodies, said upper and lower surfaces being parallel to each other along a substantial portion of the length thereof, said portion of said disc penetrating extension having a height between said upper and lower surfaces and a length sufficient to properly align and distance apart the adjacent vertebral bodies, said height being substantially equal to the normal height of the disc space between the two adjacent vertebral bodies and said length being greater than one half the depth of the disc space measured from the anterior to posterior aspect of the adjacent vertebral bodies.

29. The apparatus of claim 28 further comprising a second disc penetrating extension extending from said guard member for insertion into the disc space and for bearing against the endplates of the adjacent vertebral bodies.

30. The apparatus of claim 29 in which said disc penetrating extensions are diametrically opposed to each other and spaced apart from one another to provide access to the adjacent vertebral bodies from within the disc space.

31. The apparatus of claim 30 in which said disc penetrating extensions have the same height.

32. The apparatus of claim 28 in which the height of said disc penetrating extension has at least a portion that approximates the height of the normal disc space between the adjacent vertebral bodies.

33. The apparatus of claim 28 in which said guard member conforms at least in part to the exterior surface of the vertebral bodies of the adjacent vertebral bodies.

34. The apparatus of claim 28 further comprising means for limiting the depth of penetration of said disc penetrating extension into the disc space.

35. The apparatus of claim 34 in which said depth limiting means is located at the juncture of said disc penetrating extension and said guard member.

36. The apparatus of claim 35 in which said depth limiting means comprises a foot plate.

37. The apparatus of claim 36 further comprising means for penetrating the two adjacent vertebral bodies.

38. The apparatus of claim 37 in which said penetrating means includes teeth for insertion into at least one of the two adjacent vertebral bodies.

39. The apparatus of claim 37 in which said penetrating means includes at least one prong for insertion into at least one of the adjacent vertebral bodies.

40. The apparatus of claim 28 in which said guard member has an increased outer diameter portion at one end.

41. The apparatus of claim 28 in which said guard member comprises a hollow tube.

42. The apparatus of claim 28 in which said disc penetrating extension has a first portion for bearing against the endplates of the adjacent vertebral bodies and a second portion between said first portion and said guard member for bearing against the endplates of the adjacent vertebral bodies, said first and second portions having the same height.

43. The apparatus of claim 28 further comprising a bone removal means for forming through said guard member an implantation space across the disc space.

44. The apparatus of claim 43 in which said bone removal means is selected from the group consisting of a drill, a trephine, a reamer, an end mill, a chisel, and a burr.

45. The apparatus of claim 28 further comprising a tap for insertion through said guard member for tapping the two adjacent vertebral bodies.

46. The apparatus of claim 28 in which said disc penetrating extension has a tapered leading end to facilitate placement of said disc penetrating extension into the disc space.

47. An apparatus for use in human spinal surgery across a disc space between two adjacent vertebral bodies, comprising:

a guard member having an opening for providing protected access to the disc space and the adjacent vertebral bodies; and

a disc penetrating extension extending from said guard member for insertion into the disc space between the adjacent vertebral bodies, said disc penetrating extension having a portion for bearing against each of the adjacent endplates of the adjacent vertebral bodies, said disc penetrating extension having a tapered leading end to facilitate placement of said disc penetrating extension into the disc space, said portion of said disc penetrating extension having opposite surfaces for bearing against the endplates of the adjacent vertebral bodies, said opposite surfaces diverging away from said guard member along at least a portion of their length.

48. An apparatus for use in human spinal surgery across a disc space between two adjacent vertebral bodies, comprising:

a guard member having an opening for providing protected access to the disc space and the adjacent vertebral bodies; and

a disc penetrating extension extending from said guard member for insertion into the disc space between the adjacent vertebral bodies, said disc penetrating extension having a portion for bearing against each of the adjacent endplates of the adjacent vertebral bodies, said portion of said disc penetrating extension having an upper surface adapted to contact one of the adjacent endplates of the adjacent vertebral bodies and a lower surface adapted to contact the other of the adjacent endplates of the adjacent vertebral bodies, said disc penetrating extension having a maximum height between said upper and lower surfaces approximating the height of a normal disc space, said upper and lower surfaces converging away from said guard member along at least a portion of their length.

49. An apparatus for use in human spinal surgery across a disc space between two adjacent vertebral bodies, comprising:

a guard member having an opening for providing protected access to the disc space and the adjacent vertebral bodies; and

a disc penetrating extension extending from said guard member for insertion into the disc space between the adjacent vertebral bodies and for bearing against adjacent endplates of the adjacent vertebral bodies, said disc penetrating extension having a tapered leading end to facilitate placement of said disc penetrating extension into the disc space, said disc penetrating extension having a first portion for bearing against the endplates of the adjacent vertebral bodies and a second portion between said first portion and said guard member for bearing against the endplates of the adjacent vertebral bodies, said second portion having a height greater than the height of said first portion.

50. An apparatus for use in human spinal surgery across a disc space between two adjacent vertebral bodies, comprising:

a guard member having an opening for providing protected access to the disc space and the adjacent vertebral bodies; and

a disc penetrating extension extending from said guard member for insertion into the disc space between the adjacent vertebral bodies and for bearing against adjacent endplates of the adjacent vertebral bodies, said disc penetrating extension having a tapered leading end to facilitate placement of said disc penetrating extension into the disc space, said disc penetrating extension having a first portion for bearing against the endplates of the adjacent vertebral bodies and a second portion between said first portion and said guard member for bearing against the endplates of the adjacent vertebral bodies, said second portion having a height less than the height of said first portion.

51. An apparatus for use in human spinal surgery across a disc space between two adjacent vertebral bodies, comprising:

a guard member having an opening for providing protected access to the disc space and the adjacent vertebral bodies; and

a disc penetrating extension extending from said guard member for insertion into the disc space between the adjacent vertebral bodies, said disc penetrating extension being fixed relative to said guard member and having a portion for bearing against each of the adjacent endplates of the adjacent vertebral bodies, said disc penetrating extension having a tapered leading end to facilitate placement of said disc penetrating extension into the disc space, said portion of said disc penetrating extension having a length greater than one half the depth of the disc space measured from the anterior aspect to the posterior aspect of the disc space.

52. An apparatus for use in human spinal surgery across a disc space between two adjacent vertebral bodies, comprising:

a guard member having an opening for providing protected access to the disc space and the adjacent vertebral bodies;

a disc penetrating extension extending from said guard member for insertion into the disc space between the adjacent vertebral bodies for bearing against adjacent endplates of the adjacent vertebral bodies, said disc penetrating extension having a tapered leading end to facilitate placement of said disc penetrating extension into the disc space, said disc penetrating extension having a length greater than one half the depth of the disc space measured from the anterior aspect to the posterior aspect of the spine;

a bone removal means for forming through said guard member an implantation space across the disc space; and

an implant driver sized in part for passage through said opening for passing an implant through said guard member and into the disc space.

53. The apparatus of claim 52 in which said implant driver comprises an elongated shaft having means for engaging an implant at one end and means for manipulating said implant driver at the other end of said elongated shaft.

54. The apparatus of claim 53 further comprising means for limiting the depth of insertion of said implant driver into said guard member.

55. The apparatus of claim 54 in which said limiting means includes a portion of said implant driver cooperating with said guard member to limit the depth of insertion of said implant driver into said guard member.

56. An apparatus for use in human spinal surgery across a disc space between two adjacent vertebral bodies, comprising:

a guard member having an opening for providing protected access to the disc space and the adjacent vertebral bodies and a disc penetrating extension extending from said guard member for insertion into the disc space between the adjacent vertebral bodies, said disc penetrating extension having a portion for bearing against each of the adjacent endplates of the adjacent vertebral bodies; and

a spinal distractor sized for passage through said guard member, said spinal distractor having a body for slideably engaging the interior of said guard member and a disc penetrating member extending from said body and into the disc space between the two adjacent vertebral bodies for bearing against the adjacent endplates of the two adjacent vertebral bodies.

57. The apparatus of claim 56 in which said disc penetrating extension has a tapered leading end to facilitate placement of said disc penetrating extension into the disc space.

58. The apparatus of claim 56 in which said disc penetrating member of said spinal distractor has a first portion for bearing against one of the endplates and a second portion for bearing against a second of the endplates, said first and second portions being in an angular relationship to each other.

59. The apparatus of claim 58 in which said first and second portions of said spinal distractor diverge away from said body along at least a portion of their length.

60. The apparatus of claim 59 in which said disc penetrating extension of said guard member has opposite surfaces for bearing against the adjacent endplates of the adjacent vertebral bodies, said opposite surfaces diverging away from said guard member along at least a portion of their length.

61. The apparatus of claim 58 in which said first and second portions of said spinal distractor converge away from said body along at least a portion of their length.

62. The apparatus of claim 61 in which said disc penetrating extension has opposite surfaces for bearing against the endplates of the adjacent vertebral bodies, said opposite surfaces converging away from said guard member along at least a portion of their length.

63. An apparatus for use in human spinal surgery across a disc space between two adjacent vertebral bodies, comprising:

a guard member having an opening for providing protected access to the disc space and the adjacent vertebral bodies;

a disc penetrating extension extending from said guard member for insertion into the disc space between the adjacent vertebral bodies and for bearing against adjacent endplates of the adjacent vertebral bodies; and

an implant driver having a portion sized for passage though said opening for passing an implant through said guard member and into the disc space.

64. The apparatus of claim 63 in which said disc penetrating extension has a tapered leading end to facilitate placement of said disc penetrating extension into the disc space.

65. The apparatus of claim 63 in which said implant driver comprises an elongated shaft having means for engaging an implant at one end and means for manipulating said implant driver at the other end of said elongated shaft.

66. The apparatus of claim 65 further comprising means for limiting the depth of insertion of said implant driver into said guard member.

67. The apparatus of claim 66 in which said limiting means includes a portion of said implant driver cooperating with said guard member to limit the depth of insertion of said implant driver into said guard member.

68. An apparatus for use in performing spinal surgery across a disc space between two adjacent vertebral bodies, comprising:

a guard member having first and second passages configured to permit a spinal implant to pass through each of said first and second passages for providing protected access to the disc space and the adjacent vertebral bodies; and

a disc penetrating extension extending from said guard member for insertion into the disc space between the adjacent vertebral bodies, said disc penetrating extension having a portion for bearing against each of the adjacent endplates of the adjacent vertebral bodies.

69. The apparatus of claim 68 in which said disc penetrating extension is located between said first and second passages.

70. The apparatus of claim 68, in which said first and second passages overlap at least in part.

71. The apparatus of claim 68 in which said guard member further comprises a second disc penetrating extension for insertion into the disc space and for bearing against the adjacent endplates of the adjacent vertebral bodies.

72. The apparatus of claim 71 in which said guard member further comprises a third disc penetrating extension extending from said guard member for insertion into the disc space and for bearing against the endplates of the adjacent vertebral bodies.

73. The apparatus of claim 68 in which said portion of said disc penetrating extension has a length greater than one half the depth of the disc space measured from the anterior aspect to the posterior aspect of the spine.

74. The apparatus of claim 68 further comprising means for limiting the penetration of said disc penetrating extension into the disc space.

75. The apparatus of claim 74 in which said limiting means includes a foot plate.

76. The apparatus of claim 75 in which said foot plate is attached to said guard member proximate the junction of said guard member and said disc penetrating extension.

77. The apparatus of claim 68 including means for penetrating at least one of the two adjacent vertebral bodies.

78. The apparatus of claim 77 in which said penetrating means includes teeth for insertion into the two adjacent vertebral bodies.

79. The apparatus of claim 77 in which said penetrating means is located at the distal end of said guard member.

80. The apparatus of claim 68 in which said penetrating means includes a prong for penetrably engaging at least one of the adjacent vertebral bodies.

81. The apparatus of claim 68 further comprising means for penetrating the spine.

82. The apparatus of claim 81 in which said penetrating means includes teeth for insertion into the spine.

83. The apparatus of claim 81 in which said penetrating means includes at least one prong for insertion into the spine.

84. The apparatus of claim 81 in which said penetrating means is located at the distal end of said guard member.

85. The apparatus of claim 81 in which said penetrating means extends from a foot plate attached to said guard member at the junction of said guard member and said disc penetrating extension.

86. The apparatus of claim 68 in which said first and second passages are spaced apart from each other.

87. The apparatus of claim 68 in which said first and second passages are parallel to each other along their length.

88. The apparatus of claim 68 in which said first and second passages converge along at least a portion of their length.

89. The apparatus of claim 68 further comprising a bone removal means for forming through said guard member an implantation space across the disc space.

90. The apparatus of claim 68 further comprising a spinal distractor sized for passage through said guard member, said spinal distractor having a body and a disc penetrating member extending from said body and into the disc space between the two adjacent vertebral bodies for bearing against adjacent endplates of the two adjacent vertebral bodies.

91. The apparatus of claim 90 in which said disc penetrating member of said spinal distractor has a first portion for bearing against one of the endplates and a second portion for bearing against a second of the endplates, said first and second portions being in an angular relationship to each other.

92. The apparatus of claim 68 further comprising a tap for insertion through said guard member for tapping the two adjacent vertebral bodies.

93. Apparatus for use in performing spinal surgery across a disc space between two adjacent vertebral bodies, comprising:

a pair of hollow generally tubular members joined together partially overlapping along their longitudinal axes for providing protected access to the disc space and the adjacent vertebral bodies; and

a disc penetrating extension extending from said apparatus for insertion into the disc space between the adjacent vertebral bodies and for bearing against endplates of the adjacent vertebral bodies.

94. The apparatus of claim 93 further comprising a second disc penetrating extension extending from at least one of said pair of hollow tubular members for insertion into the disc space.

95. The apparatus of claim 94 further comprising a third disc penetrating extension extending from at least one of said pair of tubular members for insertion into the disc space and for bearing against the endplates of the adjacent vertebral bodies and for bearing against the end plates of the adjacent vertebral bodies.

96. The apparatus of claim 93 in which said disc penetrating extension has a length greater than one half the depth of the disc space.

97. The apparatus of claim 93 further comprising means for limiting the penetration of said disc penetrating extension into the disc space.

98. The apparatus of claim 97 in which said limiting means includes a foot plate.

99. The apparatus of claim 93 further comprising means for penetrating the adjacent vertebral bodies.

100. The apparatus of claim 99 in which said penetrating means comprises a prong for penetrably engaging at least one of the adjacent vertebral bodies.

101. The apparatus of claim 99 in which said penetrating means comprises teeth for penetrably engaging each of the adjacent vertebral bodies.

102. The apparatus of claim 99 in which said penetrating means is located at the distal end of at least one of said pair of tubular members.

103. The apparatus of claim 99 in which said penetrating means extends from a foot plate attached to at least one of said pair of tubular members.

104. The apparatus of claim 99 in which said penetrating means is located on a foot plate attached to at least one of said pair of tubular members.

105. The apparatus of claim 99 further comprising means for penetrating the spine.

106. The apparatus of claim 105 in which said penetrating means includes teeth for insertion into the spine.

107. The apparatus of claim 105 in which said penetrating means includes at least one prong for insertion into the spine.

108. The apparatus of claim 105 in which said penetrating means is located at the distal end of at least one of said pair of tubular members.

109. The apparatus of claim 105 in which said penetrating means includes a foot plate attached to at least one of said pair of tubular members.

110. A surgical instrument set for use in human spinal surgery across a disc space between two adjacent vertebral bodies, said surgical instrument set comprising:

a guard having an opening for providing protected access to the disc space and the adjacent vertebral bodies, said guard having a disc penetrating extension extending from said guard for insertion into the disc space between the adjacent vertebral bodies and for bearing against adjacent endplates of the adjacent vertebral bodies;

a spinal distractor sized for passage through said guard, said spinal distractor having a disc penetrating member for extension into the disc space between the two adjacent vertebral bodies for bearing against the adjacent endplates of the two adjacent vertebral bodies; and

an implant driver having means for engaging an implant, said implant driver having a portion sized for passage through said opening for passing an implant through said guard.

111. The surgical instrument set of claim 110 further comprising means for removing bone having a portion sized for passage through said opening for forming, through said guard, an implantation space across the disc space.

112. The apparatus of claim 110 in which the opening of said guard has an internal transverse cross sectional dimension approximating the transverse cross sectional dimension of a spinal implant.

113. The apparatus of claim 110 in which the internal transverse cross sectional diameter of said opening of said guard is larger than the transverse cross sectional diameter of the implant.

114. The apparatus of claim 110 in which said disc penetrating extension has a tapered leading end to facilitate placement of said disc penetrating extension into the disc space.