A new technique for reconstructions of large metadiaphyseal bone defects

Surgical Principles Tumors involving the metadiaphyseal region around the knee are often treated by intraarticular resection (and reconstructed by prosthesis or osteoarticular allografts) even when the subchondral bone could be saved and an intercalary reconstruction applied. This is due to problems associated with the reconstruction of the subarticular diaphyseal bone defects by conventional methods. Intercalary allografts (as well as cortical autografts) have significant complication rates in terms of delayed union or graft fracture: these would be significantly increased in those patients in whom an adequate osteosynthesis for support is not feasible. The use of a vascularized fibula alone is contraindicated because it cannot provide sufficient stability for the epiphysis and is too weak to allow early weight bearing. The Ilizarov technique (bone transportation) is extremely time consuming and it may be at risk in patients under aggressive chemotherapy (pin tract infection, possible interference with callus formation). Furthermore, the thin subarticular segment requires an additional ring across the joint, causing knee stiffness. The authors describe a new surgical technique to manage this surgical problem. The basic idea consists to bridge the bone defect using a massive allograft as a peripheral shell supporting a centrally placed micro-vascular fibular autograft. This technique was introduced by the first author in 1988 and preliminary results first described by Capanna et al. in 1989 and in 1991 [1, 2].