REVISION TOTAL HIP-ARTHROPLASTY IN THE DEFICIENT FEMUR WITH A PROXIMAL LOAD-BEARING PROSTHESIS

The proximal femur is frequently structurally deficient in revision hi p arthroplasty, and makes obtaining prosthesis stability more difficul t. Between 1984 and 1990, 174 patients were treated with revision tota l hip arthroplasty, performed by a standardized surgical technique, us ing cortical onlay strut allografts to restore the structural integrit y of the femur, and a calcar replacement proximally porous-coated femo ral prosthesis, composed of titanium alloy. The grafts united 98% of t he time, and showed evidence of revascularization, and in some cases, complete incorporation. To date, six have been revised for femoral fai lure. Successful reconstruction of the deficient femur after failed to tal hip arthroplasty is dependent on several factors: the revision pro sthesis must be stable, the deficient femoral bone stock must be augme nted, and load must be transferred to the proximal femur so that the f uture proximal femoral resorption is minimized. The host femur and all ograft will respond physiologically to load bearing, and the graft inc reases bone quantity and quality. The prosthesis must be supported pri marily on host bone; the graft may enhance prosthetic support, but can never be used for primary prosthetic support when using uncemented re vision prostheses.