Threaded spinal implant

• US 6,264,656 B1
• Filed: 05/08/1998
• Issued: 07/24/2001
• Est. Priority Date: 06/13/1988
• Status: Expired due to Fees

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Karlin Technology, Inc. (Medtronic Plc)
• Inventors: Michelson, Gary Karlin
• Primary Examiner(s): Brown, Michael A.
• Application Number:
  US09/075,517
• Time in Patent Office: 1,173 Days
• Field of Search: 606/60, 606/61, 623/16, 623/17, 623/18
• US Class Current: 606/86.00A
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61B 17/1757 for the spine
• CPC Class Codes: A61B 17/8888 at its central region
• CPC Class Codes: A61B 2017/0256 for the spine
• 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 2002/30235 tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30593 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 2002/3085 with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• 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 2002/4681 : by applying mechanical shocks, e.g. by hammering
• 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

An artificial spinal implant is disclosed which when place between two adjacent vertebrae directly participates and is incorporated in the insuing fusion. Instrumentation and procedure is also disclosed.

Claims

1. An artificial interbody spinal fusion implant for insertion across a disc space between two adjacent vertebral bodies of a human spine, said implant comprising:

opposed arcuate portions adapted for placement toward and at least in part within the adjacent vertebral bodies and having a distance therebetween defining an implant height greater than the normal height of the disc space to be fused, each of said opposed arcuate portions having at least one opening in communication with one another for permitting the growth of bone from vertebral body to adjacent vertebral body through said implant;

a protrusion extending from each of said opposed arcuate portions for engaging each of the adjacent vertebral bodies to maintain said implant within the disc space; and

said implant comprising at least in part of an implantation material other than bone.

2. The spinal fusion implant of claim 1, wherein said protrusion comprises a thread.

3. The spinal fusion implant of claim 1, wherein said protrusion comprises a ridge.

4. The spinal fusion implant of claim 1, wherein each of said opposed arcuate portions comprises an interior surface, said interior surfaces being spaced apart to define a hollow interior in communication with said at least one opening of each of said opposed arcuate portions.

5. The spinal fusion implant of claim 4, wherein said implant has a leading end for insertion into the spine and an opposite trailing end, at least one of said ends being open to allow access to said hollow interior.

6. The spinal fusion implant of claim 5, wherein said at least one end providing access to said hollow interior of said implant is adapted to be closed by a cap.

7. The spinal fusion implant of claim 6, wherein said implant having said at least one end providing access to said hollow interior is in combination with a cap adapted to close said hollow interior.

8. The spinal fusion implant of claim 1, further comprising a plurality of cells for retaining fusion promoting substance.

9. The spinal fusion implant of claim 1, wherein said opposed arcuate portions have a porous surface.

10. The spinal fusion implant of claim 1, wherein said implantation material is porous.

11. The spinal fusion implant of claim 1, wherein said implantation material comprises an ASTM material suitable for use as a spinal fusion implant.

12. The spinal fusion implant of claim 1, wherein said implantation material comprises titanium.

13. The spinal fusion implant of claim 1, wherein said implantation material comprises a fusion promoting substance other than bone.

14. The spinal fusion implant of claim 1, wherein said implantation material comprises a bone ingrowth material.

15. The spinal fusion implant of claim 1, wherein said implantation material intrinsically participates in the growth of bone from one of the adjacent vertebral bodies to the other of the adjacent vertebral bodies.

16. The spinal fusion implant of claim 1, wherein said implant is treated with a fusion promoting substance.

17. The spinal fusion implant of claim 1, wherein said opposed arcuate portions have a bone ingrowth surface.

18. The spinal fusion implant of claim 1, wherein said implantation material is stronger than bone.

19. The spinal fusion implant of claim 1, in combination with a source of osteogenesis.

20. The spinal fusion implant of claim 1, in combination with a bone growth promoting substance.

21. The spinal fusion implant of claim 20, in combination with bone.

22. The spinal fusion implant of claim 21, wherein said bone is compressively loaded in said implant.

23. The spinal fusion implant of claim 20, in combination with a material other than bone.

24. The spinal fusion implant of claim 20, in combination with a hydroxyapatite.

25. The spinal fusion implant of claim 1, in combination with a guard and a bone removal device, said guard for providing protected access to prepare across the spinal disc and into the adjacent vertebral bodies the implantation space, said guard having a passage through which said bone removal device passes to form the implantation space through said guard.

26. The spinal fusion implant of claim 25, wherein said implant is configured to have a height greater than the height of the implantation space and to pass through said passage of said guard.

27. The spinal fusion implant of claim 1, wherein said implant has a leading end for insertion into the spine and an opposite trailing end, said trailing end being adapted to cooperatively engage and insertion device for inserting said implant into the spine.

28. The spinal fusion implant of claim 27, in combination with an insertion device for inserting said implant into the spine, said insertion device being adapted to cooperatively engage said trailing end of said implant.

33. The spinal fusion implant of claim 20, wherein said opposed portions are arcuate.

29. An artificial interbody spinal fusion implant for insertion across a disc space between two adjacent vertebral bodies of a human spine, said implant comprising a material other than bone for use in combination with a fusion promoting substance other than bone, said implant having opposed portions adapted for placement toward the adjacent vertebral bodies and having a distance therebetween defining an implant height greater than normal height of the disc space to be fused, and said opposed portions having at least one passage passing therethrough for permitting the growth of bone from vertebral body to adjacent vertebral body through said passage.

30. The spinal fusion implant of claim 29, further comprising a protrusion extending from each of said opposed portions for engaging each of the adjacent vertebral bodies to maintain said implant within the disc space.

31. The spinal fusion implant of claim 30, wherein said protrusion comprises a thread.

32. The spinal fusion implant of claim 30, wherein said protrusion comprises a ridge.

34. The spinal fusion implant of claim 29, wherein each of said opposed portions comprise an interior surface, said interior surfaces being spaced apart to define a hollow interior in communication with said at least one opening of each of said opposed arcuate portions.

35. The spinal fusion implant of claim 34, wherein said implant has a leading end for insertion into the spine and an opposite trailing end, at least one of said ends being open to allow access to said hollow interior.

36. The spinal fusion of claim 35, wherein said at least one end providing access to said hollow interior of said implant is adapted to be closed by a cap.

37. The spinal fusion implant of claim 36, wherein said implant having said at least one end providing access to said hollow interior is in combination with a cap adapted to close said hollow interior.

38. The spinal fusion implant of claim 29, further comprising a plurality of cells for retaining a fusion promoting substance.

39. The spinal fusion implant of claim 29, wherein said opposed portions have a porous surface.

40. The spinal fusion of claim 29, wherein said implant material is porous.

41. The spinal fusion implant of claim 29, wherein said opposed portions have a bone ingrowth surface.

42. The spinal fusion implant of claim 29, wherein said implant material intrinsically participates in the growth of bone from one of the adjacent vertebral bodies to the other of the adjacent vertebral bodies.

43. The spinal fusion implant of claim 29, wherein said implant material is stronger than bone.

44. The spinal fusion implant of claim 29, in combination with a source of osteogenesis.

45. The spinal fusion implant of claim 29, in combination with a bone growth promoting substance.

46. The spinal fusion implant of claim 45, in combination with bone.

47. The spinal fusion implant of claim 46, wherein said bone is compressively loaded in said implant.

48. The spinal fusion implant of claim 45, in combination with a material other than bone.

49. The spinal fusion implant of claim 45, in combination with a hydroxyapatite.

50. The spinal fusion implant of claim 29, in combination with a guard and a bone removal device, said guard for providing protected access to prepare across the spinal disc and into the adjacent vertebral bodies the implantation space, said guard having a passage through which said bone removal device passes to form the implantation space through said guard.

51. The spinal fusion implant of claim 50, wherein said implant is configured to have a height greater than the height of the implantation space and to pass through said passage of said guard.

52. The spinal fusion implant of claim 29, wherein said implant has a leading end for insertion into the spine and an opposite trailing end, said trailing end being adapted to cooperatively engage an insertion device for inserting said implant into the spine.

53. The spinal fusion implant of claim 52, in combination with an insertion device for inserting said plant into the spine, said insertion device being adapted to cooperatively engage said trailing end of said implant.

54. An artificial interbody spinal fusion implant for insertion across a disc space between two adjacent vertebral bodies of a human spine, said implant comprising:

opposed portions adapted for placement toward the adjacent vertebral bodies and having a distance therebetween defining an implant height greater than the normal height of the disc space to be fused, said opposed portions having a plurality of openings passing therethrough for permitting the growth of bone through said implant from vertebral body to adjacent vertebral body;

a protrusion extending from each of said opposed portions for engaging the adjacent vertebral bodies to maintain said implant within the disc space and between the adjacent vertebral bodies; and

said implant comprising at least in part of a suitable implantation material other than bone.

55. The spinal fusion implant of claim 54, wherein said protrusion comprises a thread.

56. The spinal fusion implant of claim 54, wherein said protrusion comprises a ridge.

57. The spinal fusion implant of claim 54, wherein said opposed portions are arcuate.

58. The spinal fusion implant of claim 54, further comprising extensive channeling throughout said implant.

59. The spinal fusion implant of claim 54, wherein each of said opposed portions comprises an interior surface, said interior surface being spaced apart to define a hollow interior in communication with said plurality of openings of said opposed portions.

60. The spinal fusion implant of claim 59, wherein said implant has a leading end for insertion into the spine and an opposite trailing end, at least one of said ends being open to allow access to said hollow interior.

61. The spinal fusion implant of claim 60, wherein said at least one end providing access to said hollow interior of said implant is adapted to be closed by a cap.

62. The spinal fusion implant of claim 61, wherein said implant having said at least one end providing access to said hollow interior is in combination with a cap adapted to close said hollow interior.

63. The spinal fusion implant of claim 54, further comprising a plurality of cells for retaining a fusion promoting substance.

64. The spinal fusion implant of claim 54, wherein said opposed portions are porous.

65. The spinal fusion implant of claim 54, wherein said implantation material is porous.

66. The spinal fusion implant of claim 54, wherein said implantation material comprises an ASTM material suitable for use as a spinal fusion implant.

67. The spinal fusion implant of claim 54, wherein said implantation material comprises titanium.

68. The spinal fusion implant of claim 54, wherein said implantation material comprises a fusion promoting substance.

69. The spinal fusion implant of claim 54, wherein said implantation material comprises a bone ingrowth material.

70. The spinal fusion implant of claim 54, wherein said material intrinsically participates in the growth of bone from one of the adjacent vertebral bodies.

71. The spinal fusion implant of claim 54, wherein said implant is treated with a fusion promoting substance.

72. The spinal fusion implant of claim 54, wherein said implantation material is stronger than bone.

73. The spinal fusion implant of claim 54, in combination with a source of osteogenesis.

74. The spinal fusion implant of claim 54, in combination with a bone growth promoting substance.

75. The spinal fusion implant of claim 74, in combination with bone.

76. The spinal fusion implant of claim 75, wherein said bone is compressively loaded in said implant.

77. The spinal fusion implant of claim 74, in combination with a material other than bone.

78. The spinal fusion implant of claim 74, in combination with a hydroxyapatite.

79. The spinal fusion implant of claim 54, in combination with a guard and a bone removal device, said guard for providing protected access to prepare across the spinal disc and into the adjacent vertebral bodies the implantation space, said guard having a passage through which said bone removal device passes to form the implantation space through said guard.

80. The spinal fusion implant of claim 79, wherein said implant is configured to have a height greater than the height of the implantation space and to pass through said passage of said guard.

81. The spinal fusion implant of claim 54, wherein said implant has a leading end for insertion into the spine and an opposite trailing end, said trailing end being adapted to cooperatively engage an inerstion device for inserting said implant into the spine.

82. The spinal fusion implant of claim 81, wherein said implant has a leading end for inerstion into the spine, said insertion device being adapted to cooperatively engage said trailing end of said implant.

110. The spinal fusion implant of claim 82, wherein said implant has a leading end for insertion into the spine and an opposite trailing end, said trailing end being adapted to cooperatively engage an insertion device for inserting said implant into the spine.

111. The spinal fusion implant of claim 110, in combination with an insertion device for inserting said implant into the spine, said insertion device being adapted to cooperatively engage said trailing end of said iomplant.

83. An artificial interbody spinal fusion implant for insertion across a disc space between two adjacent vertebral bodies of a human spine, said implant comprising:

opposed arcuate portions adapted for placement toward and at least in part within the adjacent vertebral bodies and having a distance therebetween defining an implant height greater than the normal height of the disc space to be fused, each of said opposed arcuate portions having at least one opening communicating with one another for permitting the growth of bone from vertebral body to adjacent vertebral body through said implant;

a thread portion formed on the exterior of each of said opposed arcuate portions for engaging the adjacent vertebral bodies to maintain said implant within the disc space; and

said implant comprising at least in part of a suitable implantation material other than bone.

84. The spinal fusion implant of claim 83, wherein said thread portion is an interrupted thread.

85. The spinal fusion implant of claim 83, wherein said thread portion on each of said arcuate portions form a single helix.

86. The spinal fusion implant of claim 83, wherein each of said opposed arcuate portions comprises an interior surface, said interior surfaces being spaced apart to define a hollow interior in communication with said at least one opening of each of said opposed arcuate portions.

87. The spinal fusion implant of claim 83, in combination with a fusion promoting substance within said hollow interior.

88. The spinal fusion implant of claim 86, said implant having a leading end for insertion into the spine and an opposite trailing end, at least one of said ends being open to allow access to said hollow interior.

89. The spinal fusion implant of claim 88, wherein said at least one end providing access to said hollow interior of said implant is adapted to be closed by a cap.

90. The spinal fusion implant of claim 89, wherein said implant having said at least one end providing access to said hollow interior is in combination with a cap adapted to close said hollow interior.

91. The spinal fusion implant of claim 83, further comprising a plurality of cells for retaining fusion promoting substance.

92. The spinal fusion implant of claim 83, wherein said opposed arcuate portions have a porous surface.

93. The spinal fusion implant of claim 83, wherein said implantation material is porous.

94. The spinal fusion implant of claim 83, wherein said implantation material comprises an ASTM material suitable for use as a spinal fusion implant.

95. The spinal fusion implant of claim 83, wherein said implantation material comprises titanium.

96. The spinal fusion implant of claim 83, wherein said implantation material comprises a fusion promoting substance other than bone.

97. The spinal fusion implant of claim 83, wherein said implantation material comprises a bone ingrowth material.

98. The spinal fusion implant of claim 83, wherein said implantation material intrinsically participates in the growth of bone from one of the adjacent vertebral bodies to the other of the adjacent vertebral bodies.

99. The spinal fusion implant of claim 83, wherein said implant is treated with a fusion promoting substance.

100. The spinal fusion implant of claim 83, wherein said opposed arcuate portions have a bone ingrowth surface.

101. The spinal fusion implant of claim 83, wherein said implantation material is stronger than bone.

102. The spinal fusion implant of claim 83, in combination with a source of osteogenesis.

103. The spinal fusion implant of claim 83, in combination with a bone growth promoting substance.

104. The spinal fusion implant of claim 103, in combination with bone.

105. The spinal fusion implant of claim 104, wherein said bone is compressively loaded in said implant.

106. The spinal fusion implant of claim 103, in combination with a material other than bone.

107. The spinal fusion implant of claim 103, in combination with hydroxyapatite.

108. The spinal fusion implant of claim 83, in combination with a guard and a bone removal device, said guard for providing protected access to prepare across the spinal disc and into the adjacent vertebral bodies the implantation space, said guard having a passage through which said bone removal device passes to form the implantation space through said guard.

109. The spinal fusion implant of claim 108, wherein said implant is configured to have a height greater than the height of the implantation space and to pass through said passage of said guard.

112. An artificial interbody spinal fusion implant for insertion across a disc space between two adjacent vertebral bodies of a human spine, said implant comprising:

opposed portions adapted for placement toward and the adjacent vertebral bodies and having a distance therebetween defining an implant height greater than the normal height of the restored disc space to be fused, said opposed portions each having at least one opening passing therethrough for permitting the growth of bone through said implant from vertebral body to adjacent vertebral body;

a thread made of a surgically implantable metal extending from each of said opposed portions for engaging the adjacent vertebral bodies to maintain said implant within the disc space and between the adjacent vertebral bodies; and

said implant comprising at least in part of a suitable implantation material other than bone.

113. The spinal fusion implant of claim 112, wherein each of said opposed portions comprises an interior surface, said interior surfaces being spaced apart to define a hollow interior in communication with said at least one opening of each of said opposed portions.

114. The spinal fusion implant of claim 113, in combination with a fusion promoting substance within said hollow interior.

115. The spinal fusion implant of claim 113, said implant having a leading end for insertion into the spine and an opposite trailing end, at least one of said ends being open to allow access to said hollow interior.

116. The spinal fusion implant of claim 115, wherein said at least one end providing access to said hollow interior of said implant is adapted to be closed by a cap.

117. The spinal fusion implant of claim 116, wherein said implant having said at least one end providing access to said hollow interior is in combination with a cap adapted to close said hollow interior.

118. The spinal fusion implant of claim 112, further comprising a plurality of cells for retaining fusion promoting substance.

119. The spinal fusion implant of claim 112, wherein said opposed portions have a porous surface.

120. The spinal fusion implant of claim 112, wherein said implantation material is porous.

121. The spinal fusion implant of claim 112, wherein said implantation material comprises an ASTM material suitable for use as a spinal fusion implant.

122. The spinal fusion implant of claim 112, wherein said implantation material comprises titanium.

123. The spinal fusion implant of claim 112, wherein said implantation material comprises a fusion promoting substance other than bone.

124. The spinal fusion implant of claim 112, wherein said implantation material comprises a bone ingrowth material.

125. The spinal fusion implant of claim 112, wherein said implantation material intrinsically participates in the growth of bone from one of the adjacent vertebral bodies to the other of the adjacent vertebral bodies.

126. The spinal fusion implant of claim 112, wherein said implant is treated with a fusion promoting substance.

127. The spinal fusion implant of claim 112, wherein said opposed portions have a bone ingrowth surface.

128. The spinal fusion implant of claim 112, wherein said implantation material is stronger than bone.

129. The spinal fusion implant of claim 112, in combination with a source of osteogenesis.

130. The spinal fusion implant of claim 112, in combination with a bone growth promoting substance.

131. The spinal fusion implant of claim 116, in combination with bone.

132. The spinal fusion implant of claim 117, wherein said bone is compressively loaded in said implant.

133. The spinal fusion implant of claim 130, in combination with a material other than bone.

134. The spinal fusion implant of claim 130, in combination with hydroxyapatite.

135. The spinal fusion implant of claim 112, in combination with a guard and a bone removal device, said guard for providing protected access to prepare across the spinal disc and into the adjacent vertebral bodies the implantation space, said guard having a passage through which said bone removal device passes to form the implantation space through said guard.

136. The spinal fusion implant of claim 135, wherein said implant is configured to have a height greater than the height of the implantation space and to pass through said passage of said guard.

137. The spinal fusion implant of claim 112, wherein said implant has a leading end for insertion into the spine and an opposite trailing end, said trailing end being adapted to cooperatively engage an insertion device for inserting said implant into the spine.

138. The spinal fusion implant of claim 137, in combination with a insertion device for inserting said implant into said spine, said insertion device being adapted to cooperatively engage said trailing end of said implant.

139. An artificial interbody spinal fusion implant for insertion across a disc space between two adjacent vertebral bodies of a human spine, said implant comprising:

opposed arcuate portions adapted for placement toward and at least in part within the adjacent vertebral bodies and having a distance therebetween defining an implant height greater than the normal height of the disc space to be fused, each of said opposed arcuate portions having at least one opening communicating with one another for permitting the growth of bone from vertebral body to adjacent vertebral body through said implant;

a series of surface projections formed on the exterior of each of said opposed arcuate portions for penetrably engaging the adjacent vertebral bodies to maintain said implant within the disc space; and

said implant comprising at least in part of a suitable implantation material other than bone.

140. The spinal fusion implant of claim 139, wherein each of said series of surface projections comprises a ridge.

141. The spinal fusion implant of claim 139, wherein each of said opposed arcuate portions comprises an interior surface, said interior surfaces being spaced apart to define a hollow interior in communication with said at least one opening of each of said opposed arcuate portions.

142. The spinal fusion implant of claim 141, in combination with a fusion promoting substances within said hollow interior.

143. The spinal fusion implant of claim 141, said implant having a leading end for insertion into the spine and an opposite trailing end, at least one of said ends being open to allow access to said hollow interior.

144. The spinal fusion implant of claim 143, wherein said at least one end providing access to said hollow interior of said implant is adapted to be closed by a cap.

145. The spinal fusion implant of claim 144, wherein said implant having said at least one end providing access to said hollow interior is in combination with a cap adapted to close said hollow interior.

146. The spinal fusion implant of claim 139, further comprising a plurality of cells for retaining fusion promoting substance.

147. The spinal fusion implant of claim 139, wherein said opposed arcuate portions have a porous surface.

148. The spinal fusion implant of claim 139, wherein said implantation material is porous.

149. The spinal fusion implant of claim 139, wherein said implantation material comprises an ASTM material suitable for use as a spinal fusion implant.

150. The spinal fusion implant of claim 139, wherein said implantation material comprises titanium.

151. The spinal fusion implant of claim 139, wherein said implantation material comprises a fusion promoting substance other than bone.

152. The spinal fusion implant of claim 139, wherein said implantation material comprises bone ingrowth material.

153. The spinal fusion implant of claim 139, wherein said implantation material intrinsically participates in the growth of bone from one of the adjacent vertebral bodies to the other of the adjacent vertebral bodies.

154. The spinal fusion implant of claim 139, wherein said implant is treated with a fusion promoting substance.

155. The spinal fusion implant of claim 139, wherein said opposed arcuate portions have a bone ingrowth surface.

156. The spinal fusion implant of claim 139, wherein said implant material is stronger than bone.

157. The spinal fusion implant of claim 139, in combination with a source of osteogenesis.

158. The spinal fusion implant of claim 139, in combination with a bone growth promoting substance.

159. The spinal fusion implant of claim 158, in combination with bone.

160. The spinal fusion implant of claim 139, wherein said bone is compressively loaded in said implant.

161. The spinal fusion implant of claim 158, in combination with a material other than bone.

162. The spinal fusion implant of claim 158, in combination with hydroxyapatite.

163. The spinal fusion implant of claim 139, in combination with a guard and a bone removal device, said guard for providing protected access to prepare across the spinal disc and into the adjacent vertebral bodies the implantation space, said guard having a passage through which said bone removal device passes to form the implantation space through said guard.

164. The spinal fusion implant of claim 163, wherein said implant is configured to have a height greater than the height of the implantation space and to pass through said passage of said guard.

165. The spinal fusion implant of claim 139, wherein said implant has a leading end for insertion into the spine and an oppoiste trailing end, said trailing end being adapted to cooperatively engage an insertion device for inserting siad implant into the spine.

166. The spinal fusion implant of claim 165, in combination with an insertion device for inserting said implant into the spine, said insertion device being adapted to cooperatively engge said trailing end of said implant.