Bone cutting device and method for use thereof

• US 20040034358A1
• Filed: 08/09/2003
• Published: 02/19/2004
• Est. Priority Date: 06/10/1993
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Sofamor Danek Holdings, Inc
• Inventors: Michelson, Gary Karlin
• Granted Patent: US 7,326,214 B2
• Time in Patent Office: Days
• US Class Current: 606/79
• 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 2017/0256 for the spine
• CPC Class Codes: Y10S 623/908 Bone
• CPC Class Codes: Y10T 407/1964 Arcuate cutting edge

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.

Claims

1. A bone-cutting device adapted for use in forming an implantation space in between and at least in part into two adjacent vertebral bodies where adjacent a disc space formed by the removal of disc material from a disc between the adjacent vertebral bodies of a human spine, said bone-cutting device comprising:

a shaft having a distal end and a proximal end;

a forward projecting portion proximate said distal end of said shaft being configured to fit into the disc space, said forward projecting portion being adapted to contact each of the adjacent vertebral bodies from within the disc space; and

a cutting portion proximate said distal end of said shaft and proximate said forward projecting portion, said cutting portion having at least two opposed sharpened cutting surfaces adapted to cut bone from each of the adjacent vertebral bodies when said cutting portion is advanced into the spine behind said projecting portion.

2. The bone-cutting device of claim 1, wherein said forward projecting portion adapted to contact each of the adjacent vertebral bodies from within the disc space urges apart the adjacent vertebral bodies.

3. The bone-cutting device of claim 1, wherein said forward projecting portion adapted to contact each of the adjacent vertebral bodies from within the disc space aligns the adjacent vertebral bodies.

4. The bone-cutting device of claim 1, wherein said cutting surfaces are adapted to simultaneously cut bone from each of the adjacent vertebral bodies.

5. The bone-cutting device of claim 1, wherein said forward projecting portion has a reduced cross sectional dimension at its most distal aspect to facilitate introduction of said bone-cutting device into the disc space.

6. The bone-cutting device of claim 1, wherein said forward projecting portion has at least one of a bullet-shaped leading end, a tapered leading end, and a blunt-faced leading end.

7. The bone-cutting device of claim 1, wherein said forward projecting portion is adapted to be self-centering along a mid-longitudinal axis of said device.

8. The bone-cutting device of claim 1, wherein said forward projecting portion is one of an alignment member, a distractor, a centering post, a maximum thickness of resected bone limiter, and a means for controlling maximum thickness of bone to be resected.

9. The bone-cutting device of claim 1, wherein said shaft has a longitudinal axis and said cutting portion has a maximum dimension measured from an outer aspect of one of said cutting surfaces to an outer aspect of the opposed one of said cutting surfaces that is greater than a maximum dimension measured between where said forward projecting portion contacts each of the adjacent vertebral bodies along a plane perpendicular to the longitudinal axis of said shaft.

10. The bone-cufting device of claim 1, wherein said shaft has an enlarged portion between said cutting portion and said proximal end to limit the depth of penetration of said cutting portion into the spine.

11. The bone-cutting device of claim 10, wherein said enlarged portion comprises a collar.

12. The bone-cutting device of claim 11, wherein said collar is fixedly attached to said shaft.

13. The bone-cutting device of claim 11, wherein said collar is adjustably engaged to said shaft.

14. The bone-cutting device of claim 11, wherein said collar is lockably adjustable to said shaft.

15. The bone-cutting device of claim 1, further comprising a power unit operatively connected to said shaft for providing power to said bone-cutting device.

16. The bone-cutting device of claim 1, in combination with a guard member having an opening for providing protected access to the disc space and the adjacent vertebral bodies and for guiding said bone-cufting device into contact with the adjacent vertebral bodies.

17. The bone-cutting device of claim 1, in combination with a spinal insert adapted for insertion at least in part into the implantation space formed by said bone-cutting device.

18. The bone-cutting device of claim 17, wherein said spinal insert is a dowel.

19. The bone-cutting device of claim 17, wherein said spinal insert is an interbody spinal implant.

20. The bone-cutting device of claim 19, wherein said interbody spinal implant is an interbody spinal fusion implant.

21. The bone-cutting device of claim 19, wherein said interbody spinal implant comprises at least in part bone.

22. The bone-cutting device of claim 17, wherein said spinal insert is a bone graft.

23. The bone-cutting device of claim 17, wherein said spinal insert comprises at least in part bone.

24. The bone-cutting device of claim 17, in combination with a fusion-promoting material.

25. The bone-cutting device of claim 24, wherein said fusion-promoting material is bone.

26. The bone-cutting device of claim 24, in combination with a press for compressing said fusion-promoting material into said spinal insert.

27. The bone-cutting device of claim 17, in combination with an implant driver configured to insert said spinal insert into the implantation space formed by said bone-cutting device.

28. The bone-cutting device of claim 1, in combination with a distractor adapted to urge apart the adjacent vertebral bodies.

29. The bone-cutting device of claim 28, wherein said distractor is an interbody distractor.

30. The bone-cutting device of claim 28, in combination with at least a second distractor, said at least said second distractor being differently sized relative to said distractor to form a set of distractors of graduated sizes.

31. The bone-cutting device of claim 1, in combination with an instrument for removing from the spine the bone cut by said bone-cutting device.

137. The bone removal device of claim 1, wherein said cutting end has a plurality of cutting surfaces.

138. The bone removal device of claim 1, wherein said bone removal device comprises an end mill.

139. The bone removal device of claim 1, wherein said bone removal device comprises a drill.

32. A bone-cutting device adapted for use in forming an implantation space in between and at least in part into two adjacent vertebral bodies where adjacent a disc space formed by the removal of disc material from a disc between the adjacent vertebral bodies of a human spine, said bone-cutting device comprising:

a shaft having a longitudinal axis, a distal end, and a proximal end;

a cutting portion proximate said distal end of said shaft having a height transverse to the longitudinal axis of said shaft and at least two opposed forward facing sharpened cutting surfaces adapted to cut through bone of each of the adjacent vertebral bodies; and

a forward projecting portion extending distally beyond said cutting portion, said forward projecting portion being adapted to contact each of the adjacent vertebral bodies from within the restored disc space, said forward projecting portion having a maximum height transverse to the longitudinal axis of said shaft and a maximum length, the maximum length of said forward projecting portion being greater than one half of the maximum height of said forward projecting portion, the maximum height of said forward projecting portion being less than the height of said cutting portion.

33. The bone-cutting device of claim 32, wherein said forward projecting portion adapted to contact each of the adjacent vertebral bodies from within the disc space urges apart the adjacent vertebral bodies.

34. The bone-cutting device of claim 32, wherein said forward projecting portion adapted to contact each of the adjacent vertebral bodies from within the disc space aligns the adjacent vertebral bodies.

35. The bone-cutting device of claim 32, wherein said maximum length of said forward projecting portion is sufficient for the intended purpose of restoring the height of the disc space.

36. The bone-cutting device of claim 32, wherein said cutting surfaces are adapted to simultaneously cut bone from each of the adjacent vertebral bodies.

37. The bone-cutting device of claim 32, wherein said forward projecting portion has a reduced cross sectional dimension at its most distal aspect to facilitate introduction of said bone-cutting device into the disc space.

38. The bone-cutting device of claim 32, wherein said forward projecting portion has at least one of a bullet-shaped leading end, a tapered leading end, and a blunt-faced leading end.

39. The bone-cutting device of claim 32, wherein said forward projecting portion is one of an alignment member, a distractor, a centering post, a maximum thickness of resected bone limiter, and a means for controlling maximum thickness of bone to be resected.

40. The bone-cutting device of claim 32, wherein said shaft has an enlarged portion between said cutting portion and said proximal end to limit the depth of penetration of said cutting portion into the spine.

41. The bone-cutting device of claim 32, further comprising a power unit operatively connected to said shaft for providing power to said bone-cutting device.

42. The bone-cutting device of claim 32, in combination with a guard member having an opening for providing protected access to the disc space and the adjacent vertebral bodies and for guiding said bone-cutting device into contact with the adjacent vertebral bodies.

43. The bone-cufting device of claim 32, in combination with a spinal insert adapted for insertion at least in part into the implantation space formed by said bone-cutting device.

44. The bone-cutting device of claim 43, wherein said spinal insert is a dowel.

45. The bone-cutting device of claim 43, wherein said spinal insert is an interbody spinal implant.

46. The bone-cutting device of claim 45, wherein said interbody spinal implant is an interbody spinal fusion implant.

47. The bone-cutting device of claim 45, wherein said interbody spinal implant comprises at least in part bone.

48. The bone-cutting device of claim 43, wherein said spinal insert is a bone graft.

49. The bone-cutting device of claim 43, wherein said spinal insert comprises at least in part bone.

50. The bone-cutting device of claim 43, in combination with a fusion-promoting material.

51. The bone-cutting device of claim 50, wherein said fusion-promoting material is bone.

52. The bone-cutting device of claim 50, in combination with a press for compressing said fusion-promoting material into said spinal insert.

53. The bone-cutting device of claim 43, in combination with an implant driver configured to insert said spinal insert into the implantation space formed by said bone-cutting device.

54. The bone-cutting device of claim 32, in combination with a distractor adapted to urge apart the adjacent vertebral bodies.

55. The bone-cutting device of claim 32, in combination with an instrument for removing from the spine the bone cut by said bone-cutting device.

56. A bone-cutting device adapted for use in forming an implantation space in between and at least in part into two adjacent vertebral bodies where adjacent a disc space formed by the removal of disc material from a disc between the adjacent vertebral bodies of a human spine, said bone-cutting device comprising:

a shaft having a longitudinal axis, a distal end, and a proximal end;

a cutting portion on said shaft having a height transverse to the longitudinal axis of said shaft and at least two opposed forward facing sharpened cutting surfaces adapted to cut bone from each of the adjacent vertebral bodies; and

a forward projecting portion on said cutting portion, said forward projecting portion being adapted to urge apart the adjacent vertebral bodies, said forward projecting portion having a height transverse to the longitudinal axis of said shaft, the height of said forward projecting portion being approximately the height of a restored disc space between the adjacent vertebral bodies and being less than the height of said cutting portion.

57. The bone-cutting device of claim 56, wherein said forward projecting portion adapted to contact each of the adjacent vertebral bodies from within the disc space urges apart the adjacent vertebral bodies.

58. The bone-cutting device of claim 56, wherein said forward projecting portion adapted to contact each of the adjacent vertebral bodies from within the disc space aligns the adjacent vertebral bodies.

59. The bone-cutting device of claim 56, wherein said cutting surfaces are adapted to simultaneously cut bone from each of the adjacent vertebral bodies.

60. The bone-cutting device of claim 56, wherein said forward projecting portion has a reduced cross sectional dimension at its most distal aspect to facilitate introduction of said bone-cutting device into the disc space.

61. The bone-cutting device of claim 56, wherein said forward projecting portion has at least one of a bullet-shaped leading end, a tapered leading end, and a blunt-faced leading end.

62. The bone-cutting device of claim 56, wherein said forward projecting portion is one of an alignment member, a distractor, a centering post, a maximum thickness of resected bone limiter, and a means for controlling maximum thickness of bone to be resected.

63. The bone-cutting device of claim 56, wherein said shaft has an enlarged portion between said cutting portion and said proximal end to limit the depth of penetration of said cutting portion into the spine.

64. The bone-cutting device of claim 56, further comprising a power unit operatively connected to said shaft for providing power to said bone-cutting device.

65. The bone-cutting device of claim 56, in combination with a guard member having an opening for providing protected access to the disc space and the adjacent vertebral bodies and for guiding said bone-cutting device into contact with the adjacent vertebral bodies.

66. The bone-cutting device of claim 56, in combination with a spinal insert adapted for insertion at least in part into the implantation space formed by said bone-cutting device.

67. The bone-cutting device of claim 66, wherein said spinal insert is a dowel.

68. The bone-cutting device of claim 66, wherein said spinal insert is an interbody spinal implant.

69. The bone-cutting device of claim 68, wherein said interbody spinal implant is an interbody spinal fusion implant.

70. The bone-cutting device of claim 68, wherein said interbody spinal implant comprises at least in part bone.

71. The bone-cutting device of claim 66, wherein said spinal insert is a bone graft.

72. The bone-cutting device of claim 66, wherein said spinal insert comprises at least in part bone.

73. The bone-cutting device of claim 66, in combination with a fusion-promoting material.

74. The bone-cutting device of claim 73, wherein said fusion-promoting material is bone.

75. The bone-cutting device of claim 73, in combination with a press for compressing said fusion-promoting material into said spinal insert.

76. The bone-cutting device of claim 66, in combination with an implant driver configured to insert said spinal insert into the implantation space formed by said bone-cutting device.

77. The bone-cutting device of claim 56, in combination with a distractor adapted to urge apart the adjacent vertebral bodies.

78. The bone-cutting device of claim 56, in combination with an instrument for removing from the spine the bone cut by said bone-cutting device.

79. A bone-cutting device adapted for use in forming an implantation space in between and at least in part into two adjacent vertebral bodies where adjacent a disc space formed by the removal of disc material from a disc between the adjacent vertebral bodies of a human spine, said bone-cutting device comprising:

a shaft having a distal end and a proximal end; and

a working end attached to said distal end of said shaft, said working end comprising a forward projecting portion being configured to fit into the disc space, said forward projecting portion being adapted to contact each of the adjacent vertebral bodies from within the disc space, said working end further comprising a cutting portion proximate said forward projecting portion, said cutting portion having at least two opposed sharpened cutting surfaces adapted to cut bone from each of the adjacent vertebral bodies when said cutting portion is advanced into the spine behind said forward projecting portion.

80. The bone-cutting device of claim 79, wherein said forward projecting portion adapted to contact each of the adjacent vertebral bodies from within the disc space urges apart the adjacent vertebral bodies.

81. The bone-cutting device of claim 79, wherein said forward projecting portion adapted to contact each of the adjacent vertebral bodies from within the disc space aligns the adjacent vertebral bodies.

82. The bone-cutting device of claim 79, wherein said cutting surfaces are adapted to simultaneously cut bone from each of the adjacent vertebral bodies.

83. The bone-cutting device of claim 79, wherein said forward projecting portion has a reduced cross sectional dimension at its most distal aspect to facilitate introduction of said bone-cutting device into the disc space.

84. The bone-cutting device of claim 79, wherein said forward projecting portion has at least one of a bullet-shaped leading end, a tapered leading end, and a blunt-faced leading end.

85. The bone-cutting device of claim 79, wherein said forward projecting portion is adapted to be self-centering along a mid-longitudinal axis of said device.

86. The bone-cutting device of claim 79, wherein said forward projecting portion is one of an alignment member, a distractor, a centering post, a maximum thickness of resected bone limiter, and a means for controlling maximum thickness of bone to be resected.

87. The bone-cutting device of claim 79, wherein said shaft has a longitudinal axis and said cutting portion has a maximum dimension measured from an outer aspect of one of said cutting surfaces to an outer aspect of the opposed one of said cutting surfaces that is greater than a maximum dimension measured between where said forward projecting portion contacts each of the adjacent vertebral bodies along a plane perpendicular to the longitudinal axis of said shaft.

88. The bone-cutting device of claim 79, wherein said shaft has an enlarged portion between said cutting portion and said proximal end to limit the depth of penetration of said cutting portion into the spine.

89. The bone-cutting device of claim 88, wherein said enlarged portion comprises a collar.

90. The bone-cutting device of claim 89, wherein said collar is fixedly attached to said shaft.

91. The bone-cutting device of claim 89, wherein said collar is adjustably engaged to said shaft.

92. The bone-cutting device of claim 89, wherein said collar is lockably adjustable to said shaft.

93. The bone-cutting device of claim 79, further comprising a power unit operatively connected to said shaft for providing power to said bone-cutting device.

94. The bone-cutting device of claim 79, in combination with a guard member having an opening for providing protected access to the disc space and the adjacent vertebral bodies and for guiding said bone-cutting device into contact with the adjacent vertebral bodies.

95. The bone-cutting device of claim 79, in combination with a spinal insert adapted for insertion at least in part into the implantation space formed by said bone-cutting device.

96. The bone-cutting device of claim 95, wherein said spinal insert is a dowel.

97. The bone-cutting device of claim 95, wherein said spinal insert is an interbody spinal implant.

98. The bone-cutting device of claim 97, wherein said interbody spinal implant is an interbody spinal fusion implant.

99. The bone-cutting device of claim 97, wherein said interbody spinal implant comprises at least in part bone.

100. The bone-cutting device of claim 97, wherein said spinal insert is a bone graft.

101. The bone-cutting device of claim 97, wherein said spinal insert comprises at least in part bone.

102. The bone-cutting device of claim 97, in combination with a fusion-promoting material.

103. The bone-cutting device of claim 102, wherein said fusion-promoting material is bone.

104. The bone-cutting device of claim 102, in combination with a press for compressing said fusion-promoting material into said spinal insert.

105. The bone-cutting device of claim 95, in combination with an implant driver configured to insert said spinal insert into the implantation space formed by said bone-cutting device.

106. The bone-cutting device of claim 79, in combination with a distractor adapted to urge apart the adjacent vertebral bodies.

107. The bone-cutting device of claim 106, wherein said distractor is an interbody distractor.

108. The bone-cutting device of claim 106, in combination with at least a second distractor, said at least said second distractor being differently sized relative to said distractor to form a set of distractors of graduated sizes.

109. The bone-cutting device of claim 79, in combination with an instrument for removing from the spine the bone cut by said bone-cutting device.

110. A method for forming an implantation space at least in part within the external perimeter and in between and at least in part into two adjacent vertebral bodies where adjacent a disc space formed by the removal of disc material from a disc between the adjacent vertebral bodies of a human spine, said method comprising the steps of:

providing a bone-cutting device having a shaft having a distal end and opposite proximal end, the bone-cutting device having a forward projecting portion proximate the distal end of the shaft, the forward projecting portion being adapted to contact two adjacent vertebral bodies, the bone-cutting device having a cutting portion proximate the forward projecting portion, the cutting portion being adapted to remove bone, the cutting portion including at least two cutting surfaces having a dimension therebetween that is greater than a maximum height of the forward projecting portion when the bone-cutting device is in use;

inserting into the disc space between the adjacent vertebral bodies the forward projecting portion of the bone-cutting device to contact each of the adjacent vertebral bodies from within the disc space;

advancing the bone-cutting device further into the spine so as to cut into each of the vertebral bodies adjacent the disc space to form the implantation space for receiving a spinal insert; and

removing the bone-cutting device from the implantation space.

111. The method of claim 110, further comprising the step of inserting at least one spinal insert into the implantation space, the spinal insert having a height greater than the maximum height of the forward projecting portion.

112. The method of claim 111, wherein the spinal insert is one of a dowel, a bone graft, an interbody spinal implant, and a spinal fusion implant.

113. The method of claim 111, further comprising the step of combining the spinal insert with a fusion-promoting material to promote bone growth from adjacent vertebral body to adjacent vertebral body.

114. The method of claim 113, wherein the fusion-promoting material is bone.

115. The method of claim 111, wherein the spinal insert contains a hollow, further comprising the step of loading fusion-promoting material into the hollow of the spinal insert.

116. The method of claim 115, wherein the fusion-promoting material is bone.

117. The method of claim 110, wherein the inserting step includes the step of inserting into the disc space between the adjacent vertebral bodies the forward projecting portion of the bone-cutting device to urge apart the adjacent vertebral bodies from within the disc space.

118. The method of claim 111, wherein the inserting step includes the step of restoring the height of the disc space between the adjacent vertebral bodies.

119. An apparatus for use in spinal surgery for positioning two adjacent vertebral bodies in selected relationship to each other, said apparatus comprising:

a body having cutting flutes along an outer surface of said body; and

a disc space penetrating extension extending from said body for insertion into the disc space in between the two adjacent vertebral bodies and for bearing against adjacent endplates of the two adjacent vertebral bodies, said disc penetrating extension having a first portion for bearing against one of the adjacent endplates and a second portion for bearing against the other of the adjacent endplates.

120. The apparatus of claim 119, further comprising means for limiting the penetration of said disc penetrating extension into the disc space.

121. The apparatus of claim 119, wherein said limiting means comprises a shoulder on said body at the juncture of said disc penetrating extension and said body for preventing said body from entering the disc space.

122. The apparatus of claim 120, wherein said limiting means comprises a head associated with said disc penetrating extension, said head being dimensioned to prevent entry into the disc space.

123. The apparatus of claims 122, wherein said head has a low profile so as to minimize protrusion of said head from the two adjacent vertebral bodies.

124. The apparatus of claim 119, wherein said disc penetrating extension has surface irregularities.

125. The apparatus of claim 124, wherein said surface irregularities include ratchetings.

126. The apparatus of claim 124, wherein said surface irregularities include knurling.

127. The apparatus of claim 119, wherein said body has a mating member for mating with an extraction device for extracting said disc penetrating extension from the disc space.

128. The apparatus of claim 119, wherein said disc penetrating extension has a tapered front end to facilitate insertion of said disc penetrating extension into the disc space.

129. The apparatus of claim 119, in combination with a trephine configured for passage over said spinal distractor.

130. The apparatus of claim 119, in combination with a guard member having an opening for providing protected access to the disc space and the adjacent vertebral bodies and for guiding said device into contact with the adjacent vertebral bodies.

131. A bone removal device for use in performing spinal surgery for forming an opening in the spine, said bone removal device comprising a shaft having a longitudinal axis and terminating in a cutting end for removing bone, said cutting end having end surfaces perpendicular to the longitudinal axis and having a center which does not extend further than the rest of said cutting end, said shaft having a proximal end opposite said cutting end, said end surfaces of said cutting end and said shaft having cutting flutes over at least a portion of a length of said shaft.

132. The bone removal device of claim 131, wherein said cutting flutes are configured to guide debris generated during operation of said bone removal device toward said proximal end of said shaft.

133. The bone removal device of claim 131, wherein said center is indented.

134. The bone removal device of claim 131, wherein said proximal end of said shaft is configured for removable engagement to a driving mechanism.

135. The bone removal device of claim 131, further comprising means for limiting penetration of said cutting end into the spine.

136. The bone removal device of claim 131, wherein said limiting means is lockably adjustable.