Patent EA-001334-B1 (EA)
Title: Fusion implant device and method of use
Inventor: SCARBOROUGH NELSON
IPC: A61F2/44
Filed: 1997-09-17
Abstract: 1. An intervertebral prosthesis comprising an implant member which is a bone graft implant member dimensioned for insertion within an intervertebral space defined between adjacent vertebrae, said implant member defining a longitudinal axis and having at least first and second longitudinal sections with respective first and second cross-sectional dimensions, said first cross-sectional dimension being greater than said second crosssection dimension to define a retaining surface of said implant member wherein upon insertion of said implant member between the vertebrae said retaining surface facilitates securement therewithin by corresponding engagement with surfaces of the adjacent vertebrae. 2. The intervertebral prosthesis according to claim 1 wherein said implant member is generally circular in cross-section. 3. The intervertebral prosthesis according to claim 2 wherein said second longitudinal section defines a diameter ranging from about 50% to about 95% the diameter defined by said first longitudinal section. 4. The intervertebral prosthesis according to claim 1 wherein said implant member is generally wedge-shaped. 5. The intervertebral prosthesis according to claim I wherein the implant member defines a single stepped region. 6. The intervertebral prosthesis according to claim I wherein said implant member includes multiple stepped regions. 7. The intervertebral prosthesis according to claim I wherein said implant member is a bone graft implant. 8. The intervertebral prosthesis according to claim 1 wherein said implant member comprises cancellous bone or cortical bone. 9. The intervertebral prosthesis according to claim 1 wherein said implant member defines an interior hollow cavity for accommodating bone growth inducing material. 10. The intervertebral prosthesis according to claim 9 including bone growth inducing material disposed in said interior hollow cavity, said bone growth inducing material including bone growth factors, glycerol, demineralized bone matrix (dbm), bone marrow, bone morphogenic protein (BMP-4). 11. The intervertebral prosthesis according to claim 9 wherein said implant member includes at least one opening extending through an outer surface in communication with bone growth inducing matcrial disposed within said hollow cavity. 12. An intervertebral prosthesis comprising an implant member of biocompatible material and being dimensioned for positioning between adjacent vertebrae, said implant member including first and second generally cylindrical sections, first cylindrical section defining a diameter greater than a diameter defined by the second cylindrical section, the juncture of said first and second cylindrical sections defining a retaining ledge such that upon insertion of said implant member between the adjacent vertebrae in a manner to prevent movement relative to the vertebrae thereby facilitating retainment therein. 13. The intervertebral prosthesis according to claim 12 wherein said first and second cylindrical sections are concentrically arranged about a longitudinal axis of said implant member. 14. The intervertebral prosthesis according to claim 12 wherein said implant member has a non-threaded exterior surface. 15. The intervertebral prosthesis according to claim 12 wherein said implant member includes a plurality of annular grooves formed on an exterior surface portion thereof. 16. The intervertebral prosthesis according to claim 13 wherein said implant member defines anterior and posterior ends, said first cylindrical section disposed adjacent said anterior end. 17. The intervertebral prosthesis according to claim 12 wherein said implant member comprises cortical bone. 18. The intervertebral prosthesis according to claim 12 wherein said implant member comprises cancellous bone. 19. A vertebral interbody fusion device comprising a bone graft implant member dimensioned to span an intervertebral space between adjacent vertebrae, said implant member having a non-threaded outer surface and first and second longitudinal sections, with respective first and second cross-sectional dimensions, the juncture of said first and second longitudinal section defining a retaining surface, said retaining surface facilitating retention of said implant member within said intervertebral space through cooperative engagement with corresponding surfaces of the adjacent vertebrae.