Bone cutting device and method for use thereof

• US 7,399,303 B2
• Filed: 08/20/2002
• Issued: 07/15/2008
• Est. Priority Date: 06/10/1993
• Status: Expired due to Fees

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Michelson, Gary Karlin
• Primary Examiner(s): Brown; Michael A.
• Application Number:
  US10/223,916
• Publication Number:
  US 20020198532A1
• Time in Patent Office: 2,156 Days
• Field of Search: 606/61, 606/62, 606 88- 96, 606/60, 606 79- 80
• 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 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.

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 includes opposed upper and lower surfaces configured to urge 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 includes opposed upper and lower surfaces configured to align 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 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.

8. The bone-cutting 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.

9. 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.

10. 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-cutting device into contact with the adjacent vertebral bodies.

11. 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.

12. The bone-cutting device of claim 11, wherein said spinal insert is a dowel.

13. The bone-cutting device of claim 11, wherein said spinal insert is an interbody spinal implant.

14. The bone-cutting device of claim 13, wherein said interbody spinal implant is an interbody spinal fusion implant.

15. The bone-cutting device of claim 13, wherein said interbody spinal implant comprises at least in part bone.

16. The bone-cutting device of claim 11, wherein said spinal insert is a bone graft.

17. The bone-cutting device of claim 11, wherein said spinal insert comprises at least in part bone.

18. The bone-cutting device of claim 11, in combination with a fusion-promoting material.

19. The bone-cutting device of claim 18, wherein said fusion-promoting material is bone.

20. The bone-cutting device of claim 18, in combination with a press for compressing said fusion-promoting material into said spinal insert.

21. The bone-cutting device of claim 11, in combination with an implant driver configured to insert said spinal insert into the implantation space formed by said bone-cutting device.

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

23. 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.

24. 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 forward projecting portion further into the spine so as to cut into each of the vertebral bodies adjacent the disc space with the cutting portion to form the implantation space for receiving a spinal insert while the forward projecting portion is being advanced; and

removing the bone-cutting device from the implantation space.

25. The method of claim 24, 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.

26. The method of claim 25, wherein the spinal insert is one of a dowel, a bone graft, an interbody spinal implant, and a spinal fusion implant.

27. The method of claim 25, 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.

28. The method of claim 27, wherein the fusion-promoting material is bone.

29. The method of claim 25, wherein the spinal insert contains a hollow, further comprising the step of loading fusion-promoting material into the hollow of the spinal insert.

30. The method of claim 29, wherein the fusion-promoting material is bone.

31. The method of claim 24, 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.

32. The method of claim 25, wherein the inserting step includes the step of restoring the height of the disc space between the adjacent vertebral bodies.