Calcar resorption beneath a well-fitting flanged femoral prosthesis.

Forty-three of 51 Link SP hip prostheses inserted 4 years previous to this study were clinically and radiographically reviewed. All demonstrated bone resorption in excess of 2 mm under the collar, but this resorption was not progressive. No prosthesis had loosened. The collar of a prosthesis, even when securely cemented into the femur with a carefully matched neck cut, was decoupled from its functional position in all the reviewed cases at 4 years. Its only remaining function was to prevent subsidence within the cement mantle, should it ever become necessary to provide stability.