Revision total hip arthroplasty in the deficient femur with a proximal load-bearing prosthesis

The proximal femur is frequently structurally deficient in revision hip arthroplasty, and makes obtaining prosthesis stability more difficult. Between 1984 and 1990, 174 patients were treated with revision total hip arthroplasty, performed by a standardized surgical technique, using cortical onlay strut allografts to restore the structural integrity of the femur, and a calcar replacement proximally porous-coated femoral prosthesis, composed of titanium alloy. The grafts united 98% of the time, and showed evidence of revascularization, and in some cases, complete incorporation. To date, six have been revised for femoral failure. Successful reconstruction of the deficient femur after failed total hip arthroplasty is dependent on several factors: the revision prosthesis must be stable, the deficient femoral bone stock must be augmented, and load must be transferred to the proximal femur so that the future proximal femoral resorption is minimized. The host femur and allograft will respond physiologically to load bearing, and the graft increases bone quantity and quality. The prosthesis must be supported primarily on host bone; the graft may enhance prosthetic support, but can never be used for primary prosthetic support when using uncemented revision prostheses.