Interbody fusion grafts and instrumentation

• US 7,637,953 B2
• Filed: 10/31/2003
• Issued: 12/29/2009
• Est. Priority Date: 10/28/1998
• Status: Expired due to Fees

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Josse, Loic, Liu, Mingyan, Boyd, Lawrence M., Branch, Charles L.
• Primary Examiner(s): Philogene; Pedro
• Application Number:
  US10/698,702
• Publication Number:
  US 20040093083A1
• Time in Patent Office: 2,251 Days
• Field of Search: 623 1711- 1716, 606/61, 606/246, 606/248
• US Class Current: 623/17.11
• CPC Class Codes: A61B 17/1604 Chisels; Rongeurs; Punches; Stamps
• CPC Class Codes: A61B 17/1659 Surgical rasps, files, planes, or scrapers
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61B 17/1739 specially adapted for particular parts of the body
• CPC Class Codes: A61B 17/1757 for the spine
• CPC Class Codes: A61B 17/1778 for the shoulder
• CPC Class Codes: A61B 17/88 Osteosynthesis instruments; Methods or means for implanting or extracting internal or external fixation devices A61B17/7074 takes precedence
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61B 2017/922 Devices for impaction, impact element
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• 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 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/4601 for introducing bone substitute, for implanting bone graft implants or for compacting them in the bone cavity
• 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 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• 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 2002/2839 Bone plugs or bone graft dowels
• CPC Class Codes: A61F 2002/30131 horseshoe- or crescent- or C-shaped or U-shaped
• CPC Class Codes: A61F 2002/30158 : trapezoidal
• CPC Class Codes: A61F 2002/30168 : L-shaped
• CPC Class Codes: A61F 2002/30192 : J-shaped
• CPC Class Codes: A61F 2002/3028 : polyhedral different from parallelepipedal and pyramidal
• CPC Class Codes: A61F 2002/30774 : internally-threaded
• CPC Class Codes: A61F 2002/3082 : Grooves
• CPC Class Codes: A61F 2002/30845 : with cutting edges
• CPC Class Codes: A61F 2002/30879 : Ribs
• CPC Class Codes: A61F 2002/30892 : parallel
• 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 2002/4627 : 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 2002/4628 : with linear motion along or rotating motion about an axis transverse to the instrument axis or to the implantation direction, e.g. clamping
• 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 2230/0013 : Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2230/0026 : trapezoidal
• CPC Class Codes: A61F 2230/0041 : J-shaped
• CPC Class Codes: A61F 2230/0043 : L-shaped
• CPC Class Codes: A61F 2230/0063 : Three-dimensional shapes
• CPC Class Codes: Y10S 606/909 : Bone
• CPC Class Codes: Y10S 606/914 : Toolkit for installing or removing spinal positioner or stabilizer

Abstract

This invention relates to implants formed from donor bone for use in lumbar interbody fusion procedures and instruments for performing such procedures. The implants are formed to include a concave surface formed from a portion of the medullary canal of a long bone. The concave surface defines a recess in the implant that serves as a depot for osteogenic material. Specific instruments for inserting the implants prepared according to this invention and for preparing the intervertebral space to receive the implants are also provided.

Claims

1. A spinal implant, comprising:

an elongate bone portion formed from a cross-sectional bone slice taken from a diaphysis of a long bone having an outer cortical bone wall surrounding an inner medullary canal, said elongate bone portion having a longitudinal axis and including;

a first end portion;

a second end portion arranged generally opposite said first end portion;

a first bone engaging surface;

a second bone engaging surface arranged generally opposite said first bone engaging surface;

a first sidewall extending between said first and second bone engaging surfaces and including a recessed area disposed between said first and second end portions, said recessed area defined by a partial portion of the medullary canal of the long bone and defining a concave outer surface extending along said longitudinal axis between said first and second end portions from said first bone engaging surface to said second bone engaging surface; and

a second sidewall arranged generally opposite said first sidewall relative to said longitudinal axis, said second sidewall extending between said first and second bone engaging surfaces and including a convex outer surface extending along said longitudinal axis between said first and second end portions from said first bone engaging surface to said second bone engaging surface; and

wherein said concave outer surface of said first sidewall extends generally parallel with and is positioned opposite said convex outer surface of said second sidewall to provide said elongate bone portion with an elongate crescent-shaped outer cross-section in a plane including said longitudinal axis.

2. A system including a pair of the spinal implants of claim 1 wherein said pair of spinal implants includes a first implant and a second implant, said first and second implants positioned adjacent one another with said concave outer surface of said first implant facing said concave outer surface of said second implant with said concave outer surfaces defining a chamber therebetween.

3. The system of claim 2 further comprising an osteogenic material disposed within said chamber defined between said concave outer surfaces of said first and second implants.

4. The system of claim 2 wherein said first and second implants are positioned such that said longitudinal axis of said first implant lies at an angle oblique angle relative to said longitudinal axis of said second implant.

5. The implant of claim 1 wherein said elongate bone portion has a generally rectangular cross-section in a plane including the longitudinal axis.

6. The implant of claim 1 wherein each of said first and second bone engaging surfaces is substantially planar.

7. The implant of claim 6 wherein each of said first and second bone engaging surfaces includes ridges or teeth.

8. The implant of claim 6 wherein each of said first and second bone engaging surfaces is crescent-shaped.

9. The implant of claim 1 wherein said first and second bone engaging surfaces are separated by a first height adjacent said first end portion and by a second height adjacent said second end portion, wherein said first height is greater than the second height.

10. The implant of claim 1 further comprising a first endwall extending between said first and second bone engaging surfaces, wherein said first endwall includes one or more engagement features adapted to engage an implant holder.

11. The implant of claim 10 wherein said engagement features comprise a recess or a projection configured to engage the implant holder.

12. The implant of claim 10 wherein said engagement features comprise an opening extending through said first endwall to said concave outer surface of said first sidewall.

13. The implant of claim 12 wherein said opening is threaded.

14. The implant of claim 1 wherein one of said first and second end portions comprises an insertion end, said insertion end being shaped to facilitate insertion into a vertebral cavity.

15. The implant of claim 14 wherein said insertion end is tapered to facilitate insertion into the vertebral cavity.

16. The implant of claim 15 wherein said insertion end includes:

a first tapered surface extending from said first bone engaging surface; and

a second tapered surface extending from said second bone engaging surface; and

wherein said first and second tapered surfaces are inwardly tapered toward one another along said insertion end.

17. The implant of claim 16 wherein said insertion end includes a third tapered surface extending from said convex outer surface of said second sidewall.

18. The implant of claim 17 wherein said insertion end includes a fourth tapered surface extending from said concave outer surface of said first sidewall;

and

wherein said third and fourth tapered surfaces taper toward one another along said insertion end.

19. The implant of claim 15 wherein said insertion end includes:

a first tapered surface extending from said convex outer surface of said second sidewall; and

a second tapered surface extending from said concave outer surface of said first sidewall; and

wherein said first and second tapered surfaces are inwardly tapered toward one another along said insertion end.

20. The implant of claim 15 wherein said insertion end is bounded on at least three sides by tapered surfaces.

21. The implant of claim 14 wherein said insertion end is bullet-shaped to facilitate insertion into the vertebral cavity.

22. A method of forming a spinal implant, comprising:

providing a long bone having a diaphysis;

removing a cross-sectional bone slice from the diaphysis of the long bone, the cross-sectional bone slice including an outer cortical bone wall surrounding an inner medullary canal having a length;

cutting the bone slice along the length of the medullary canal and dividing the bone slice into a plurality of bone slice segments, with each of the bone slice segments including a partial portion of the outer cortical bone wall and a partial portion of the medullary canal; and

forming the spinal implant of claim 1 from one of the plurality of bone slice segments, with the recessed area of the first sidewall defined by the partial portion of the medullary canal.

23. The method of claim 22 further comprising forming the spinal implant from each of the plurality of bone slice segments obtained from a single bone slice.

24. The method of claim 22 wherein the cutting of the bone slice along the length of the medullary canal comprises dividing the bone slice into three bone slice segments, with each of the three bone slice segments including a partial portion of the outer cortical bone wall and a partial portion of the inner medullary canal.

25. The method of claim 24 further comprising forming the spinal implant from each of the three bone slice segments obtained from a single bone slice.

26. The method of claim 22 further comprising forming a cylindrical bone dowel from one of the bone slice segments;

and

forming the spinal implant from one of the remaining bone slice segments.

27. A method of forming a spinal implant, comprising:

providing a long bone having a diaphysis;

removing a cross-sectional bone slice from the diaphysis of the long bone, the cross-sectional bone slice including an outer cortical bone wall surrounding an inner medullary canal having a length;

cutting the bone slice along the length of the medullary canal and dividing the bone slice into a plurality of bone slice segments, with each of the bone slice segments including a partial portion of the outer cortical bone wall and a partial portion of the medullary canal; and

forming an elongate bone portion from one of the plurality of bone slice segments, the elongate bone portion having a longitudinal axis and including;

a first end portion;

a second end portion arranged generally opposite the first end portion;

a first bone engaging surface;

a second bone engaging surface arranged generally opposite the first bone engaging surface; and

a first sidewall extending between the first and second bone engaging surfaces and including a recessed area disposed between the first and second end portions, the recessed area defined by the partial portion of the medullary canal and defining a concave outer surface extending along the longitudinal axis between the first and second end portions from the first bone engaging surface to the second bone engaging surface.

28. The method of claim 27 further comprising forming the elongate bone portion from each of the plurality of bone slice segments obtained from a single bone slice.

29. The method of claim 27 wherein the cuffing of the bone slice along the length of the medullary canal comprises dividing the bone slice into three bone slice segments, with each of the three bone slice segments including a partial portion of the outer cortical bone wall and a partial portion of the inner medullary canal.

30. The method of claim 29 further comprising forming the elongate bone portion from each of the three bone slice segments obtained from a single bone slice.

31. The method of claim 27 further comprising forming a cylindrical bone dowel from one of the bone slice segments;

and

forming the elongate bone portion from one of the remaining bone slice segments.

32. The method of claim 27 wherein the elongate bone portion has a generally rectangular cross-section in a plane including the longitudinal axis.

33. The method of claim 27 wherein each of the first and second bone engaging surfaces is substantially planar.

34. The method of claim 33 further comprising providing each of the first and second bone engaging surfaces with a plurality of ridges or teeth.

35. The method of claim 27 wherein the elongate bone portion further includes a second sidewall arranged generally opposite the first sidewall relative to the longitudinal axis, the second sidewall extending between the first and second bone engaging surfaces and including a convex outer surface extending along the longitudinal axis between the first and second end portions from the first bone engaging surface to the second bone engaging surface;

and

wherein the concave outer surface of the first sidewall extends generally parallel with and is positioned opposite the convex outer surface of the second sidewall to provide the elongate bone portion with an elongate crescent-shaped outer cross-section in a plane including the longitudinal axis.

36. The method of claim 27 wherein the elongate bone portion further includes a second sidewall arranged generally opposite the first sidewall relative to the longitudinal axis, the second sidewall extending between the first and second bone engaging surfaces and including a substantially planar outer surface extending along the longitudinal axis between the first and second end portions from the first bone engaging surface to the second bone engaging surface;

and

wherein the concave outer surface defined by the first sidewall is positioned opposite the substantially planar outer surface of the second sidewall relative to the longitudinal axis.

37. The implant of claim 36 wherein the first sidewall includes:

a first substantially planar outer surface adjacent the first end portion and a second substantially planar outer surface adjacent the second end portion, each of the first and second substantially planar outer surfaces extending between the first and second bone engaging surfaces; and

wherein the concave outer surface extends axially between the first and second substantially planar outer surfaces.

38. The method of claim 27 wherein the first and second bone engaging surfaces are separated by a first height adjacent the first end portion and by a second height adjacent the second end portion, wherein the first height is greater than the second height.

39. The method of claim 27 wherein the elongate bone portion further includes a first endwall extending between the first and second bone engaging surfaces, wherein the first endwall includes one or more engagement features adapted to engage an implant holder.