In revision total hip replacement surgery, treatment of the expanded femoral medullary canal is a challenging problem. Large volumes of cement, or massive custom components frequently fail and result in even larger defects and thinning of the remaining cortices.
In this article, seventeen patients with intramedullary structural grafts were followed for an average of 50 months with a range of 8 months to 8 years, three months. There were 16 allografts and one iliac crest autograft. Nine cancellous metaphyseal grafts were shaped as a truncated cone and were impacted within the host metaphysis. The femoral component was then cemented within the graft. I now prefer to use an allograft proximal tibia and to protect the host femur with circlage cables. The ZTT metaphyseal unit of the Joint Medical Stem (Stamford, CT) is cemented to the graft and the fluted stem is used in the host femur without cement.
Seven smaller allograft femurs were impacted within the expanded diaphyseal canal of the host femur and new femoral components were cemented within these grafts. I now prefer to machine the outer diameter of a smaller femur to just fit within the host medullary canal but leave an abrupt shelf at the host graft junction. The distal allograft is pressfit within the host but the butt joint resists further subsidence. The host femur is protected by a circlage cable. All nine metaphyseal grafts united. Five of the smaller allograft femurs united, but two did not and both subsided. The two grafts that did not unite were technical failures as a butt joint was not used and fixation was achieved only by a pressfit.