Vascularized Bone Allotransplantation: Current State and Implications for Future Reconstructive Surgery

Segmental bone defects resulting from traumatic loss, osteomyelitis, and osteolysis after arthroplasty and limb-sparing tumor surgery are encountered commonly in orthopedic practice. Allograft bone, matched to fit the defect and secured with internal fixation, is used frequently for the reconstruction of these difficult problems. Late stress fracture, infection, and non-unions are frequent complications when nonviable bone is used. Living autogenous bone, whose circulation in maintained by microvascular repair, can adapt to stress and heals much more readily. Living autografts have limited reconstructive potential, however, because of the size, shape, and strength of available donor sites. A living allograft transplant would combine the best characteristics of allograft and living autograft reconstruction. Current research is focused on overcoming the potentially serious problems associated with immunosuppressive treatments. The use of surgical angiogenesis combined with short-term immunosuppression may maintain viability of a vascularized bone allograft without need for long-term immunosuppression or induction of tolerance.