Open intervertebral spacer

• US 7,273,498 B2
• Filed: 01/13/2004
• Issued: 09/25/2007
• Est. Priority Date: 06/03/1997
• Status: Expired due to Term

• Current Assignee: RTI Surgical Incorporated
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Bianchi, John R., Estes, Bradley T., Boyd, Larry, Carter, Kevin C., Pafford, John A.
• Primary Examiner(s): GHERBI, SUZETTE JAIME J
• Application Number:
  US10/756,971
• Publication Number:
  US 20040148029A1
• Time in Patent Office: 1,351 Days
• Field of Search: 623 1711- 1716
• US Class Current: 623/17.16
• CPC Class Codes: A61B 17/1604 Chisels; Rongeurs; Punches; Stamps
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61B 17/8875 Screwdrivers, spanners or wrenches
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/30724 Spacers for centering an implant in a bone cavity, e.g. in a cement-receiving cavity
• 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 2/446 having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones
• CPC Class Codes: A61F 2/4601 for introducing bone substitute, for implanting bone graft implants or for compacting them in the bone cavity
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2/4644 Preparation of bone graft, bone plugs or bone dowels, e.g. grinding or milling bone material bone material A61F2/28; disintegrating or milling devices B02C
• CPC Class Codes: A61F 2/468 Testing instruments for artificial joints for testing non-implantable prostheses A61F2/76
• 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 2002/30057 made from both cortical and cancellous adjacent parts
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30131 horseshoe- or crescent- or C-shaped or U-shaped
• CPC Class Codes: A61F 2002/30143 hexagonal
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30594 : slotted, e.g. radial or meridian slot ending in a polar aperture, non-polar slots, horizontal or arcuate slots
• CPC Class Codes: A61F 2002/30616 : Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30617 : Visible markings for adjusting, locating or measuring
• CPC Class Codes: A61F 2002/30772 : Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30795 : Blind bores, e.g. of circular cross-section
• CPC Class Codes: A61F 2002/30797 : internally-threaded
• CPC Class Codes: A61F 2002/3082 : Grooves
• CPC Class Codes: A61F 2002/30871 : Trapezoidal threads
• 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 2002/4635 : using minimally invasive surgery
• CPC Class Codes: A61F 2002/4649 : Bone graft or bone dowel harvest sites
• CPC Class Codes: A61F 2210/0004 : bioabsorbable
• CPC Class Codes: A61F 2230/0013 : Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2230/0017 : Angular shapes
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2250/0097 : Visible markings, e.g. indicia
• CPC Class Codes: A61F 2310/00011 : Metals or alloys
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures
• CPC Class Codes: Y10S 623/908 : Bone

Abstract

Open chambered spacers, implanting tools and methods are provided. The spacers 500′ include a body 505′ having a wall 506′ which defines a chamber 530′ and an opening 531′ in communication with the chamber 530′. In one embodiment the wall 506′ includes a pair of arms 520′, 521′ facing one another and forming a mouth 525′ to the chamber 530′. Preferably, one of the arms 520′ is truncated relative to the other, forming a channel 526. In one aspect the body 505′ is a bone dowel comprising an off-center plug from the diaphysis of a long bone. The tools 800 include spacer engaging means for engaging a spacer and occlusion means for blocking an opening defined in the spacer. In some embodiments, the occlusion means 820 includes a plate 821 extendable from the housing 805. In one specific embodiment the plate 821 defines a groove 822 which is disposed around a fastener 830 attached to the housing 805 so that the plate 821 is slideable relative to the housing 805.

Claims

1. A method for fusing two adjacent vertebrae, comprising the steps of:

providing a spacer formed of cortical bone, the spacer including a body having a wall, said wall having an outer surface including a concave portion defining a chamber, an opening in communication with said chamber, and a channel defined in said wall in communication with said chamber and said outer surface;

preparing the vertebrae and the intervertebral space between the vertebrae to receive the spacer; and

placing the spacer into the intervertebral space.

2. The method of claim 1 wherein said outer surface includes a curved portion and a flattened portion.

3. The method of claim 1 wherein said body further comprises an outer surface that defines a curved portion and a flattened portion.

4. A method for fusing two adjacent vertebrae, said method comprising:

preparing a space between the two adjacent vertebrae to receive a graft;

providing a graft composed of cortical bone and comprising an elongated body having an outer surface and a longitudinal axis along a length of said body, said outer surface including a chamber having a substantially concave surface and extending along a second axis substantially perpendicular to said longitudinal axis, said graft defining a channel extending between said chamber and said outer surface in a direction transverse to said second axis; and

implanting the graft in the space between the two adjacent vertebrae.

5. The method of claim 4 wherein said preparing comprises performing a discectomy on a patient in need thereof.

6. The method of claim 4 wherein the outer surface of the body defines threaded bone engaging portions.

8. The method of claim 4 wherein said graft is a bone dowel obtained from the diaphysis of a long bone having a medullary canal, said chamber including a portion of the canal.

9. The method of claim 4 wherein said body comprises upper and lower flattened portions.

10. The method of claim 4 wherein the outer surface comprises vertebrae engaging surfaces.

11. The method of claim 4 wherein the vertebrae engaging surfaces comprise ribs, grooves or threads.

12. The method of claim 4 further comprising an osteogenic material packed within said cavity.

13. The method of claim 12 wherein the osteogenic material is packed within the cavity prior to implantation of the graft.

14. The method of claim 12 wherein the osteogenic material is packed within the cavity after implantation of the graft.

15. The method of claim 4 comprising placing osteogenic material in the space around the graft.

16. The method of claim 4 comprising threadingly implanting the graft in to the space.

17. The method of claim 16 wherein the graft includes a tool engagement end having an alignment mark and wherein said threadingly implanting comprises orientating the alignment mark to facilitate placement of the graft in the space as desired.

18. The method of claim 16 comprising implanting a second graft into the space.

19. The method of claim 18 wherein the second graft includes a tool engagement having an alignment mark and wherein said implanting a second graft comprises orientating the alignment mark of the second graft to facilitate placement of the second graft in the space as desired.

20. The method of claim 4 wherein said implanting comprises impacting the graft into the space.

21. The method of claim 4 comprising implanting a second graft into the space.

22. The method of claim 4, wherein the graft includes a tool engagement end and said implanting comprises attaching an insertion tool having a shaft to the engagement end of the graft.

23. The method of claim 22 wherein the shaft is threaded and said attaching comprising threadedly engaging the shaft with the graft.

24. The method of claim 4 wherein the graft includes a tool engagement end and said implanting comprises attaching an insertion tool to the engagement end of the graft, said insertion tool comprising an occlusion member configured to overlay at least a portion of the chamber.

25. The method of claim 24 comprising packing the chamber with an osteogenic material and extending the occlusion member to overlay at least a portion of the chamber.

26. The method of claim 4 wherein the graft includes a channel extending from the tool engagement end to the chamber, and said occlusion member is configured to be slidable received within the channel.

27. The method of claim 22 wherein the insertion tool includes an extendable shaft to engage with the engagement end of the graft.

28. The method of claim 4 wherein the graft includes a tool engagement end and said implanting comprises attaching an insertion tool having a pair of prongs configured to engage the outer surface of the graft.

29. The method of claim 28 wherein the insertion tool includes an extendable shaft to engage with the engagement end of the graft.

7. A method for fusing two adjacent vertebrae, said method comprising:

preparing a space between the two adjacent vertebrae to receive a graft;

providing a graft composed of cortical bone and comprising an elongated body having an outer surface and a longitudinal axis alone a length of said body, said outer surface including a chamber having a substantially concave surface and extending along a second axis substantially perpendicular to said longitudinal axis, wherein the body includes a C-shaped wall defining the chamber; and

implanting the graft in the space between the two adjacent vertebrae.

30. A method for fusing two adjacent vertebrae, said method comprising:

preparing a disc space between the two adjacent vertebrae to receive a spacer

providing a spacer comprising a C-shaped body formed of cortical bone, said body comprising a cavity having a concave surface; and

implanting the spacer in the space between the two adjacent vertebrae.

31. The method of claim 30 comprising inserting an osteogenic material into the cavity.

32. The method of claim 31 wherein the osteogenic material is inserted into the cavity prior to implantation of the spacer into the disc space.

33. The method of claim 31 wherein the osteogenic material is inserted into the cavity after to implantation of the spacer into the disc space.

34. The method of claim 30 comprising threadingly implanting the spacer in to the disc space.

35. The method of claim 34 wherein the spacer comprises vertebrae engaging surfaces including on of ribs, grooves and threads.

36. The method of claim 30 comprising impacting the spacer into the disc space.

37. The method of claim 36 wherein the spacer is provided as a dowel having a substantially round cross sectional area when viewed adjacent a first end.

38. The method of claim 36 wherein the spacer is provided with flattened upper and lower surfaces.

39. The method of claim 30 wherein the spacer comprises vertebrae engaging surfaces including on of ribs, grooves and threads.

40. The method of claim 30 wherein the spacer includes a tool engagement end having an alignment mark and wherein said implanting comprises orientating the alignment mark to facilitate placement of the spacer in the disc space as desired.

41. The method of claim 30 comprising implanting a second spacer into the disc space.

42. The method of claim 41 wherein the second spacer includes a tool engagement end having an alignment mark and wherein said implanting a second spacer comprises orientating the alignment mark of the second spacer to facilitate placement of the spacer in the disc space as desired.

43. The method of claim 42 wherein said orientating the alignment mark of the second spacer comprising orientating the second spacer relative to the first spacer so that the cavity of the first spacer and the cavity of the second spacer oppose each other in the disc space.

44. The method of claim 30 wherein the spacer includes a tool engagement end and said implanting comprises attaching an insertion tool having an extendable shaft to the engagement end of the spacer.

45. The method of claim 30 wherein the spacer includes a tool engagement end and said implanting comprises attaching an insertion tool to the engagement end of the spacer, said insertion tool comprising an occlusion member configured to extend to overlay at least a portion of the chamber.

46. The method of claim 30 wherein the spacer includes a tool engagement end and said implanting comprises attaching an insertion tool having a pair of prongs configured to engage the C-shaped body.