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 th e routine use of the tibia for donor bone tissue is precluded by its e ssential weight-bearing function, in select cases it provides a useful alternative to standard donor bone sources. Cadaver dissection was pe rformed to confirm the endosteal and periosteal vascular anatomy of th e tibia. The presence of a consistent nutrient vessel was confirmed. S elective dye injection demonstrated a dual cortical blood supply based on both the endosteal nutrient vessel and multiple periosteal perfora tor vessels, Inclusion of both vascular supplies maximizes perfusion o f bone and periosteum, thus potentially optimizing bone healing and os seous union, Based on these findings, the vascularized tibial bone fla p 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 u nsuccessful. The patient presented with a chronic right femur nonunion with painful pseudoarthrosis; frozen knee joint; and an internally ro tated, 20.3-cm shortened, nonfunctional lower limb. Femur length proxi mal to the nonunion was less than 15 cm, A maximum amputation stump le ngth is recommended for optimal prosthetic function. A 15-cm pedicled tibial bone flap based on the posterior tibial endosteal and periostea l vascular supply was reversed and plated to the proximal femur to pro vide a stump of adequate length to optimize prosthetic fitting and fun ction, 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 i mmunosuppressive therapy. Transfer based on the posterior tibial pedic le, which includes the endosteal nutrient vessel as well as the perios teal supply via the tibialis posterior muscle, maximizes bone perfusio n. The pedicle is of sufficient length to be used for positioning the tibia in the thigh or for free transfer to distant sites.