Knee arthroplasty prosthesis
A knee arthroplasty prosthesis includes a femoral component having multiple pieces with engagement means provided for engaging various pieces of the femoral component to one another following their insertion in the incised area of the femur. A tibial component includes multiple pieces designed for assembly following positioning in the incision. The tibial component includes a Morse taper cavity on one piece of the tibial component and a Morse taper extension on another member of the component for receipt therein.
1. A femoral component for knee arthroplasty in a knee having a natural patella or a prosthetic patella comprising:
(a) a first piece having a patellar femoral flange portion including an articulating surface for engagement by said patella, said first piece extending from an anterior end toward a posterior end and having one or more engagement surfaces defining one side of a joint, said first piece including a central surface extending laterally and first and second side engagement surfaces extending from said central surface angularly away from each other in a direction toward said anterior end;
(b) a second piece defining first and second condylar portions and having an articulating surface, said second piece extending from said posterior end toward said anterior end and having one or more abutment surfaces cooperating with said engagement surfaces to define said joint;
(c) at least one laterally extending cross member located adjacent said abutment surfaces and connecting said first condylar portion to said second condylar portion, said cross member has (i) a medial surface spaced from said condylar portion articulating surface, (ii) an opposed bone engaging surface, and (iii) a leading surface facing said first piece and extending between said medial surface and said bone engaging surface and wherein said first piece includes a ledge extending anteriorly from said central surface, said ledge engaged to said medial surface of said cross member;
(d) a posterior cam located adjacent said posterior end and connecting said first condylar portion to said second condylar portion; and
(e) a fastener for securing said first piece and said second piece together such that said posterior cam is spaced apart and separate from said first piece.
2. The femoral component of claim 1 wherein said first piece comprises a first aperture and said second piece comprises a second aperture, said fastener fittable through said first aperture and said second aperture to secure said first piece to said second piece.
3. The femoral component of claim 1 wherein said first and second side engagement surfaces of said first piece define curved engagement surfaces following a contour for mating engagement with said abutment surfaces of said second piece.
4. The femoral component of claim 1 wherein said abutment surfaces and said engagement surfaces define a recessed joint.