Femur lengthening with a vascularized tibia bone flap.

A vascularized tibial bone flap based on a single nutrient vessel has been previously proposed for use in long-bone reconstruction. While the routine use of the tibia for donor bone tissue is precluded by its essential weight-bearing function, in select cases it provides a useful alternative to standard donor bone sources. Cadaver dissection was performed to confirm the endosteal and periosteal vascular anatomy of the tibia. The presence of a consistent nutrient vessel was confirmed. Selective dye injection demonstrated a dual cortical blood supply based on both the endosteal nutrient vessel and multiple periosteal perforator vessels. Inclusion of both vascular supplies maximizes perfusion of bone and periosteum, thus potentially optimizing bone healing and osseous union. Based on these findings, the vascularized tibial bone flap was applied to a clinical case. A 45-year-old male veteran sustained a right proximal femur fracture in a motor vehicle accident. Multiple attempts at fusion with open reduction, internal fixation, grafting, and nonvascularized fibular onlay strut with cerclage wires were all unsuccessful. The patient presented with a chronic right femur nonunion with painful pseudoarthrosis; frozen knee joint; and an internally rotated, 20.3-cm shortened, nonfunctional lower limb. Femur length proximal to the nonunion was less than 15 cm. A maximum amputation stump length is recommended for optimal prosthetic function. A 15-cm pedicled tibial bone flap based on the posterior tibial endosteal and periosteal vascular supply was reversed and plated to the proximal femur to provide a stump of adequate length to optimize prosthetic fitting and function. The tibia is essential for normal weight-bearing, but in select cases may be sacrificed for use in long-bone reconstruction. Expanded use of tibial vascularized allografts in long-bone reconstruction may be made possible following future development of effective and safe immunosuppressive therapy. Transfer based on the posterior tibial pedicle, which includes the endosteal nutrient vessel as well as the periosteal supply via the tibialis posterior muscle, maximizes bone perfusion. The pedicle is of sufficient length to be used for positioning the tibia in the thigh or for free transfer to distant sites.