Method and apparatus for replacing a spinal disc
An apparatus for replacing a spinal disc which has a rail extending from the outer surface to connect the apparatus to the first vertebra. The rail extends a first distance from the outer surface adjacent a first end. The rail extends a second distance from the outer surface adjacent a second end. The second distance is greater than the first distance. In another aspect of the apparatus, the first rail extends generally transverse to the first and second ends. The second rail extends generally transverse to the first rail.
1. An apparatus for replacing a spinal disc in a spinal column, said apparatus comprising:
a first end;
a second opposite end;
first and second lateral sides extending between said first and second ends;
an outer surface engageable with a first vertebra of the spinal column;
first and second rails extending from said outer surface, said first rail having a length extending generally transverse to said first and second ends, said second rail having a length extending generally transverse to said first rail, said first rail including a plurality of projections extending from said outer surface;
a resilient core having a first surface and a second surface;
a first retaining device connected to said first surface of said resilient core, said first retaining device having said outer surface engageable with the first vertebra of the spinal column and an inner surface facing said first surface of said resilient core, said first retaining device including a first mounting member and a first retaining member, said first retaining member having an inner surface affixed to said first surface of said core, said first mounting member including an inner surface facing said core and spaced from said first surface of said core, said first mounting member including said first and second rails; and
a second retaining device connected to said second surface of said resilient core, said second retaining device having an outer surface engageable with a second vertebra of the spinal column and an inner surface facing said second surface of said resilient core.
2. An apparatus as set forth in claim 1 wherein said first and second rails have lengths extending generally perpendicular to each other.
3. An apparatus as set forth in claim 1 wherein said first rail includes a recess for providing bony ingrowth.
4. An apparatus as defined in claim 1 wherein said first retaining member has an opening extending through said inner and outer surfaces of said first retaining member, said first mounting member being located in said opening.
5. An apparatus as defined in claim 4 wherein said opening extends axially through said first retaining member.
6. An apparatus as defined in claim 4 wherein said first mounting member is connected to said first retaining member.
7. An apparatus as defined in claim 6 wherein said first mounting member is prevented from moving relative to said first retaining member.