Fusion implant device and method of use

• US 6,045,580 A
• Filed: 10/09/1998
• Issued: 04/04/2000
• Est. Priority Date: 09/06/1996
• Status: Expired due to Fees

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Osteotech Incorporated (Medtronic Plc)
• Inventors: Morris, John W., Scarborough, Nelson
• Primary Examiner(s): Isabella, David J.
• Application Number:
  US09/169,209
• Time in Patent Office: 543 Days
• Field of Search: 623/16, 623/17, 623/18, 606/61
• US Class Current: 623/17.11
• 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 2017/0256 for the spine
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• 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 2/446 having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones
• CPC Class Codes: A61F 2/4644 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 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/30233 Stepped cylinders, i.e. having discrete diameter changes
• CPC Class Codes: A61F 2002/30266 wedge-shaped parallelepipeds
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30785 parallel
• CPC Class Codes: A61F 2002/30787 inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30828 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 2230/0069 cylindrical
• CPC Class Codes: A61F 2230/0082 parallelepipedal
• CPC Class Codes: A61F 2310/00017 Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures
• CPC Class Codes: Y10S 606/907 : Composed of particular material or coated
• CPC Class Codes: Y10S 606/909 : Bone
• CPC Class Codes: Y10S 606/91 : Polymer
• CPC Class Codes: Y10S 606/913 : Monolithic

Abstract

An intervertebral prosthesis includes a bone graft implant member dimensioned for insertion within an intervertebral space defined between adjacent vertebrae and having at least first and second longitudinal sections with respective first and second cross-sectional dimensions. The first cross-sectional dimension of the first implant section is greater than the second cross-section dimension of the second implant section to define a stepped region having a retaining surface. Consequently, upon insertion of the implant member within a generally correspondingly dimensioned receiving bed formed within the adjacent vertebrae, the retaining surface facilitates securement therewithin by corresponding engagement with surfaces of the receiving bed. a method for fusion of adjacent vertebrae utilizing the prosthesis is also disclosed.

Claims

1. An intervertebral prosthesis comprising an implant member having a first end and a second end and being dimensioned for insertion within a receiving bed formed in opposed faces of adjacent vertebrae, said implant member defining a longitudinal axis and having a first longitudinal section having a first planar surface and a second longitudinal section having a second planar surface, the implant member having a wedge-shaped configuration and a height which increases from the first end to the second end along the longitudinal axis, the first planar surface defining a first anile with respect to the longitudinal axis and the second planar surface defining a second angle with respect to the longitudinal axis, the second angle being greater than the first angle.

2. An intervertebral prosthesis according to claim 1, further including a retaining surface formed on the implant member, the retaining surface including at least one stepped region.

3. An intervertebral prosthesis according to claim 2, wherein the at least one stepped region includes two stepped regions.

4. An intervertebral prosthesis according to claim 2, wherein the at least one stepped region is formed by removing a portion of the second longitudinal section.

5. An intervertebral prosthesis according to claim 1, wherein the implant member is formed from bone.

6. An intervertebral prosthesis according to claim 5, wherein the bone comprises at least one of cancellous and cortical bone.

7. An intervertebral prosthesis according to claim 1, wherein the implant member comprises a biocompatible material selected from the group consisting of titanium, titanium alloys, surgical steel, polymeric material and ceramic material.

13. An intervertebral prosthesis according to claim 1, wherein the first end of the implant member defines the greatest height of the implant member.

8. An intervertebral implant for insertion within a receiving bed located between adjacent vertebrae, the implant comprising a body having a longitudinal axis and including a front wall, a rear wall, a pair of sidewalls, a top surface and a bottom surface, the pair of sidewalls decreasing in height from the front wall to the rear wall such that the implant has a wedge-shaped configuration, and at least one cutout formed at the intersection of the front wall and at least one of the sidewalls and extending between the top and bottom surfaces, the cutout defining a stepped portion having one wall which is substantially parallel to the sidewalls and a second wall which is substantially parallel to the front and rear walls.

9. An intervertebral implant according to claim 8, wherein the at least one cutout includes first and second cutouts.

10. An intervertebral implant according to claim 8, wherein the implant is formed from bone.

11. An intervertebral implant according to claim 10, wherein the bone is selected from the group consisting of cancellous bone and cortical bone.

12. An intervertebral implant according to claim 8, wherein the implant comprises a biocompatible material selected from the group consisting of titanium, titanium alloys, surgical grade steel, polymeric material and ceramic material.