Intervertebral implant

• US 6,547,823 B2
• Filed: 06/08/1999
• Issued: 04/15/2003
• Est. Priority Date: 01/22/1999
• Status: Expired due to Fees

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Osteotech Incorporated (Medtronic Plc)
• Inventors: Boyle, John W., Scarborough, Nelson L.
• Primary Examiner(s): Robert, Eduardo C.
• Application Number:
  US09/328,283
• Publication Number:
  US 20010016775A1
• Time in Patent Office: 1,407 Days
• Field of Search: 623/17.16, 623/17.11, 623/17.12, 623/17.15, 623/23.63, 623/901, 623/925, 623/17
• US Class Current: 623/17.16
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/30771 applied in original prostheses, e.g. holes or grooves
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• 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 2/4611 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 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 2002/2825 Femur
• 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 2002/30153 rectangular
• CPC Class Codes: A61F 2002/30158 trapezoidal
• CPC Class Codes: A61F 2002/30205 conical
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30225 Flat cylinders, i.e. discs
• CPC Class Codes: A61F 2002/3023 wedge-shaped cylinders
• CPC Class Codes: A61F 2002/30266 wedge-shaped parallelepipeds
• CPC Class Codes: A61F 2002/30772 Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30774 : internally-threaded
• CPC Class Codes: A61F 2002/30785 : parallel
• CPC Class Codes: A61F 2002/30789 : perpendicular with respect to each other
• CPC Class Codes: A61F 2002/3079 : Stepped or enlarged apertures, e.g. having discrete diameter changes
• CPC Class Codes: A61F 2002/30879 : Ribs
• CPC Class Codes: A61F 2002/30884 : Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity
• CPC Class Codes: A61F 2002/30892 : parallel
• CPC Class Codes: A61F 2002/30902 : laterally or radially
• CPC Class Codes: A61F 2002/30904 : serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/30971 : Laminates, i.e. layered products
• 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 2002/4649 : Bone graft or bone dowel harvest sites
• CPC Class Codes: A61F 2230/0019 : rectangular
• CPC Class Codes: A61F 2230/0026 : trapezoidal
• CPC Class Codes: A61F 2230/0067 : conical
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0082 : parallelepipedal
• CPC Class Codes: A61F 2240/001 : Designing or manufacturing processes
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00131 : Tantalum or Ta-based alloys
• CPC Class Codes: A61F 2310/00293 : containing a phosphorus-containing compound, e.g. apatite
• CPC Class Codes: A61F 2310/00359 : Bone or bony tissue
• CPC Class Codes: Y10S 623/901 : Method of manufacturing prosthetic device

Abstract

An intervertebral implant having a composite wedge/dowel configuration is provided. The intervertebral implant includes a central body portion and a pair of radially extending wings. The radially extending wings can be tapered from a first end of the implant to the second end of the implant along an axis parallel to the longitudinal axis of the central body portion. Alternately, the radially extending wings can be tapered along an axis transverse to the longitudinal axis of the cylindrical body portion or along any other axis between parallel and transverse to the longitudinal axis. A throughbore or plurality of throughbores extend from a top surface of the implant through the implant to a bottom surface of the implant. The implant may be formed from a cortical ring cut from the diaphysis of a long bone by milling the top and bottom surfaces of the cortical ring to form the substantially central body portion and the tapered radially extending wings. The cortical ring is milled such that the intramedullary canal of the cortical ring defines a throughbore in the central body portion of the implant. The sidewalls of the implant may be machined to form a substantially rectangular shape or the implant can be left to have a substantially circular configuration. Alternately, the implant may be formed of any biocompatible material having the requisite strength requirements via any known process, i.e., molding.

Claims

1. An intervertebral implant comprising:

a first central body portion having a longitudinal axis; and

at least one wing extending radially outwardly from the central body portion, the central body portion and the at least one wing being formed of bone and being of monolithic construction;

wherein the at least one radially extending wing has a height which decreases along the longitudinal axis of the central body portion from one end of the central body portion to the other end of the central body portion.

2. An intervertebral implant according to claim 1 wherein the intervertebral implant includes two radially extending wings, each of the radially extending wings having a shape substantially the same as the other radially extending wing.

3. An intervertebral implant according to claim 1, wherein the implant is manufactured from the diaphysis or the metaphysis of a long bone.

4. An intervertebral implant according to claim 3, further including a throughbore defined by the intramedullary canal of the long bone.

5. An intervertebral implant according to claim 1, wherein the implant is manufactured from a cortical ring cut from the diaphysis or metaphysis of a long bone.

6. An intervertebral implant according to claim 1, further including protrusions formed on the surface of the intervertebral implant.

7. An intervertebral implant according to claim 6, wherein the protrusions are formed on the at least one radially extending wing.

8. An intervertebral implant according to claim 1, wherein the implant is formed from a bone derived composite material.

9. An intervertebral implant according to claim 1, wherein the implant is formed from a bone derived layered material.

10. An intervertebral implant according to claim 1, further including at least one throughbore defined in the central body portion, the throughbore having an axis which is substantially perpendicular to the longitudinal axis of the central body portion.

11. An intervertebral implant according to claim 1, wherein the bone is partially demineralized.

12. An intervertebral implant according to claim 1, wherein the first central body portion is frustoconical.

13. An intervertebral implant comprising:

a first central body portion having a longitudinal axis; and

a pair of wings extending radially outwardly from the central body portion, one of the pair of wings extending from one side of the central body portion and the other of the pair of wings extending from an opposite side of the central body portion, wherein the central body portion and the pair of wings are formed of bone.

14. An intervertebral implant according to claim 13, wherein the implant is manufactured from the diaphysis or the metaphysis of a long bone.

15. An intervertebral implant according to claim 13, wherein the implant is manufactured from a cortical ring cut from the diaphysis or metaphysis of a long bone.

16. An intervertebral implant according to claim 13, further including at least one throughbore defined in the central body portion, the throughbore having an axis which is substantially perpendicular to the longitudinal axis of the substantially cylindrical body portion.

17. An intervertebral implant according to claim 13, wherein each of the radially extending wings includes a top and a bottom surface, the top and bottom surfaces being shaped to conform to a vertebral endplate'"'"'s shape.

18. An intervertebral implant according to claim 13, wherein the bone is partially demineralized.

19. An intervertebral implant according to claim 13, wherein the implant is surface demineralized.