Apparatus and method for preparing a site for an interbody fusion implant

• US 5,700,264 A
• Filed: 07/01/1996
• Issued: 12/23/1997
• Est. Priority Date: 07/01/1996
• Status: Expired due to Fees

• Current Assignee: James F. Zucherman, Ken Y. Hsu
• Original Assignee: James F. Zucherman, Ken Y. Hsu
• Inventors: Zucherman, James F., Hsu, Ken Y.
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): Woo, Julian W.
• Application Number:
  US08/673,127
• Time in Patent Office: 540 Days
• Field of Search: 606/79, 606/82, 606/61, 606/170, 606/172, 606/179, 606/180, 606/183, 606/184, 606/159, 128/755, 604/22, 408/36, 408/204, 408/703
• US Class Current: 606/79
• CPC Class Codes: A61B 17/1637 Hollow drills or saws producing a curved cut, e.g. cylindrical A61B10/025, A61B17/1695 take precedence
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61B 17/1757 for the spine
• CPC Class Codes: A61F 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442

Abstract

An instrument set 20 and method for preparing a site between adjacent bones for insertion of an implant includes an alignment probe 22 with a head end 24 and a cutter 34 which fits over the alignment probe 22. The alignment probe 22 can be appropriately positioned using imaging techniques and then given a quarter turn in order to anchor the head end 24 in the bones at the appropriate depth and with the appropriate alignment. The cutter 34 is then inserted over the alignment probe 22 in order to sever bone and tissue. After this is accomplished, the head end 24 is given another quarter turn freeing itself from the bone, and then the alignment probe 22 and the cutter 34 are removed with the tissue and bone captured therebetween.

Claims

1. An instrument set for forming a bore between adjacent spaced bones comprising:

an alignment probe with a head end mounted on a post;

said head end including a first arm and a second arm;

said first arm having first and second lateral sides, and said second arm having third and fourth lateral sides;

wherein said first lateral side of said first arm is on the same side of the head end as said third lateral side of said second arm, and said second lateral side of said first arm is on the same side of the head end as said fourth lateral side of said second arm;

wherein said first lateral side is sharpened and said fourth lateral side is sharpened;

a cutter which fits over said post and which has a distal cutting edge;

said cutting edge describes a width; and

said width is less than the combined length of said first arm and said second arm such that said first arm and said second arm provide a stop for said cutter.

2. The instrument set of claim 1 wherein:

said cutter is cylindrical and said distal cutting edge is circular.

3. The instrument set of claim 1 including:

a spacer with a tip which is adapted to distract adjacent bones.

4. The instrument set of claim 1 wherein:

the adjacent spaced bones are first and second bones and the first and fourth lateral sides of the alignment probe are adapted for cutting into the first and second bones respectively order to position the alignment probe between the first and second bones.

5. An instrument set for forming a bore between adjacent spaced bones comprising:

an alignment probe with a head end mounted on a post;

said head end including a first arm and a second arm;

said first arm having first and second lateral sides, and said second arm having third and fourth lateral sides;

wherein said first lateral side of said first arm is on the same side of the head end as said third lateral side of said second arm, and said second lateral side of said first arm is on the same side of the head end as said fourth lateral side of said second arm;

wherein said first lateral side is sharpened and said fourth lateral side is sharpened;

a cutter which fits over said post and which has a distal cutting edge; and

a sharpened edge projects forwardly from said first arm and said second arm.

6. An alignment probe for establishing a desired alignment between spaced bones comprising:

a head end mounted on a post;

said head end including a first arm and a second arm;

said first arm having first and second lateral sides, and said second arm having third and fourth lateral sides;

wherein said first lateral side of said first arm is on the same side of said head end as said third lateral side of said second arm, and said second lateral side of said first arm is on the same side of said head end as said fourth lateral side of said second arm;

wherein said first lateral side is sharpened and said fourth lateral side is sharpened; and

a sharpened edge projects forwardly from said first arm and said second arm.

7. The alignment probe of claim 6 wherein:

said alignment probe is substantially T-shaped.

8. The alignment probe of claim 6 wherein:

said first arm and said second arm are directed oppositely from each other.

9. The alignment probe of claim 6 wherein:

said first arm and said second arm together describe a length of between about thirteen millimeters and about twenty-one millimeters.

10. The alignment probe of claim 6 wherein:

said first arm and said second arm together describe a length of one of thirteen millimeters, seventeen millimeters, and twenty-one millimeters.

11. A method for forming a bore between first and second bones comprising the steps of:

selecting an alignment probe which alignment probe comprises;

a head end mounted on a post;

said head end including a first arm and a second arm;

said first arm having first and second lateral sides, end said second arm having third and fourth lateral sides;

wherein said first lateral side of said first arm is on the same side of said head end as said third lateral side of said second arm, and said second lateral side of said first arm is on the same side of said head end as said fourth lateral side of said second arm;

wherein said first lateral side is sharpened and said fourth lateral side is sharpened;

positioning the alignment probe with the first arm and the second arm between the two bones;

twisting the alignment probe until the sharpened first lateral side of the first arm is secured in the first bone and the sharpened fourth lateral side of the second arm is secured in the second bone in order to align the alignment probe relative to the first and second bones;

placing a cutter over the post, which cutter has a distal cutting edge;

operating the cutter in order to cut into the first bone and the second bone in order to define a bore; and

removing the alignment probe and the cutter with the cut bone.

12. The method of claim 11 including the steps of:

performing the operating step until the cutter comes into contact with the arms of the alignment probe.

13. The method of claim 11 including the step of:

placing a spacer over the post of the alignment probe prior to placing the cutter over the alignment probe in order to appropriate position the cutter relative to the alignment probe.

14. The method of claim 11 including the step of:

said positioning step includes aligning the post of the alignment probe relative to the first bone and the second bone prior to twisting the alignment probe.

15. The method of claim 11 including the step of:

using an imaging instrument during the positioning step to align the post of the alignment probe relative to the first bone and the second bone prior to twisting the alignment probe.

16. The method of claim 11 wherein the first and second bones are first and second vertebrae with disk space located therebetween and wherein:

said positioning step include positioning said first arm and said second arm of said alignment tool in the disk space between the first and second vertebrae.

17. The method of claim 16 including the step of:

removing disk material from between first and second vertebrae prior to positioning the first arm and the second arm of the alignment tool in the disk space.

18. The method of claim 11 wherein said first bone is a first vertebra and said second bone is a second vertebra and a disk is located between said first vertebra and said second vertebra, and wherein said selecting step includes:

selecting an alignment probe with a sharpened edge projecting forwardly from said first arm and said second arm; and

using the sharpened edge to cut the disk in order to position the alignment tool between the first vertebra and the second vertebra.

19. The method of claim 11 including the steps of:

placing a spacer with a tip over the alignment probe prior to placing the cutter over the alignment probe; and

positioning the tip between the bones in order to distract the bones.

20. The method of claim 11 wherein:

the cutter has a width and said width is less than the combined length of the first arm and said second arm such that said first arm and said second arm provide a stop for the cutter, wherein the method includes;

performing the operating step until the cutter comes into contact with the arms of the adjacent probe.

22. The method of claim 11 including the step of:

placing a spacer with a tip over the alignment probe in order to distract the first and second bones prior to twisting the alignment probe.

35. The method of claim 11 including the steps of:

placing a spacer with a tip over the alignment probe prior to placing the cutter over the alignment probe; and

positioning the tip between the bones in order to distract the bones prior to the step of operating the cutter.

21. An alignment probe instrument set for providing alignment relative to a first vertebra and a second vertebra so that a bore can be created in order to introduce an implant into the disk space between the first vertebra and the second vertebra such that the implant spans the disk space and projects into and engages the first vertebra and the second vertebra, said instrument set comprising:

an alignment probe having;

a. head end mounted on a post;

b. said head end including an elongate member which is transverse to said post;

c. said elongate member including a first arm and a second arm;

d. said first arm having a first sharpened side and said second arm having a second sharpened side;

a spacer with a central bore which fits over said post;

a cutter with a distant cutting edge; and

wherein said cutter fits over said spacer and is guided by said spacer and said alignment probe to a location relative to said first vertebra and said second vertebra.

34. The instrument set of claim 21 wherein:

said spacer has a tip which is adapted to distract the first and second vertebrae.

23. An alignment probe for providing alignment relative to a first vertebra and a second vertebra so that a bore can be created in order to introduce an implant into the disk space between the first vertebra and the second vertebra such that the implant spans the disk space and projects into and engages the first vertebra and the second vertebra, said alignment probe comprising:

a head end mounted on a post;

said head end including an elongate member which is transverse to said post;

said elongate member including a first arm and a second arm;

said first arm having first and second lateral sides, and said second arm having third and fourth lateral sides;

said first lateral side of said first arm is on the same side of said head end as is the third lateral side of said second arm, and said second lateral side of said first arm is on the same side of the head end as the fourth lateral side of said second arm;

wherein said first lateral side is sharpened and said fourth lateral side is sharpened; and

said head end is Z-shaped.

24. The alignment probe of claim 23 wherein:

said head end has a length of about 13 millimeters to about 21 millimeters.

25. The alignment probe of claim 23 wherein:

said head end has a length selected from one of about 13 millimeters, 17 millimeters, and about 21 millimeters.

26. An alignment probe for providing alignment relative to a first vertebra and a second vertebra so that a bore can be created in order to introduce an implant into the disk space between the first vertebra and the second vertebra such that the implant spans the disk space and projects into and engages the first vertebra and the second vertebra, said alignment probe comprising:

a head end mounted on a post;

said head end including an elongate member which is transverse to said post;

said elongate member including a first arm and a second arm;

said first arm having first and second lateral sides, and said second arm having third and fourth lateral sides;

said first lateral side of said first arm is on the same side of said head end as is the third lateral side of said second arm, and said second lateral side of said first arm is on the same side of the head end as the fourth lateral side of said second arm;

wherein said first lateral side is sharpened and said fourth lateral side is sharpened; and

said head end is S-shaped.

27. An alignment probe for providing alignment relative to a first vertebra and a second vertebra so that a bore can be created in order to introduce an implant into the disk space between the first vertebra and the second vertebra such that the implant spans the disk space and projects into and engages the first vertebra and the second vertebra, said alignment probe comprising:

a head end mounted on a post;

said head end including an elongate member which is transverse to said post;

said elongate member including a first arm and a second arm;

said first arm having first and second lateral sides, and said second arm having third and fourth lateral sides;

said first lateral side of said first arm is on the same side of said head end as is the third lateral side of said second arm, and said second lateral side of said first arm is on the same side of the head end as the fourth lateral side of said second arm;

wherein said first lateral side is sharpened and said fourth lateral side is sharpened; and

,

a sharpened edge projecting forwardly from said first arm and said second arm.

28. The alignment probe of claim 27 wherein:

said first lateral side of said first arm is in line with the third lateral side of said second arm, and said second lateral side of said first arm is in line with the fourth lateral side of said second arm.

29. An instrument set for forming a bore between adjacent spaced bones comprising:

an alignment probe with a head end mounted on a post;

said head end including a first arm and a second arm;

said first arm having first and second lateral sides, and said second arm having third and fourth lateral sides;

wherein said first lateral side of said first arm is on the same side of the head end as said third lateral side of said second arm, and said second lateral side of said first arm is on the same side of the head end as said fourth lateral side of said second arm;

wherein said first lateral side is sharpened and said fourth lateral side is sharpened;

a cutter which fits over said post and which has a distal cutting edge;

a spacer with a central bore which fits over said post; and

wherein said cutter fits over said spacer and is guided by said spacer and said alignment probe to a location relative to the adjacent spaced bones.

30. The instrument set of claim 29 wherein:

said spacer has a tip which is adapted to distract the adjacent bones.

31. An alignment probe for establishing a desired alignment between spaced bones comprising:

a head end mounted on a post;

said head end adapted to be positioned between the bones;

said head end having means for penetrating the bones so that said head end can be anchored between the spaced bones; and

said head end includes stop flanges which are adapted to prevent a cutter from penetrating the bone to a depth that is past said stop flanges.

32. An alignment probe for establishing a desired alignment between spaced bones comprising:

a head end mounted on a post with a longitudinal axis;

said head end adapted to be movable past the outwardly facing exterior surfaces of the bones and such that the head end can be positioned between the bones;

said head and having an anchor device that can penetrate both of the bones substantially simultaneously when the post is twisted along the longitudinal axis so that said head end can be anchored between the spaced bones; and

said head end includes at least one stop which is adapted to prevent a cutter from penetrating the bone to a length that is past said stop.

33. The alignment probe of claim 32 wherein the bones are spaced apart first vertebra and second vertebra with a disk space located therebetween and wherein:

said head end is sized so that it can fit into the disk space between the first vertebra and the second vertebra prior to being twisted in order to be anchored in the first vertebra and the second vertebra.

36. An instrument set for forming a bore between adjacent spaced first and second bones comprising:

an alignment probe with a head end mounted on a post;

said head end having first and second arms;

said first arm having a sharpened first side which is adapted for cutting into the first bone and the second arm having sharpened second side which is adapted for cutting into the second bone as the sharpened first side cuts into the first bone;

wherein the action of the sharpened first side and sharpened second side in cutting into the first and second bones respectively securely positions the probe between the first and second bones and established an alignment between said first and second bones;

a cutter with a distal cutting edge that is guided by the post of the alignment probe to a position adjacent to the first and second bones after the alignment probe is secured to and aligned between the first and second bones; and

said first and second arms including stop flanges which prevent said cutter from penetrating the first and second bones to a depth which is past said stop flanges.