Use of circular external fixation to maintain foot position during free tissue transfer to the foot and ankle

Abstract

Limb salvage techniques of traumatized extremities using free-tissue transfer and microsurgical techniques have become standard reconstructive methods. To our knowledge there is no published data on the incidence or likelihood of equinus following free tissue transfer about the ankle, although in our experience we have perceived an unacceptable incidence of equinus following free tissue transfers about the ankle and therefore initiated prophylactic ring fixation across the ankle. Fourteen patients were placed in circular external fixation spanning the ankle at the time of free tissue transfer for a mean of 12 weeks (Median 7 weeks, Range 6-28 weeks). The results were evaluated using the degree of active ankle dorsiflexion and return to independent ambulation. Six patients had excellent results with active ankle dorsiflexion beyond neutral, and four patients had good results with neutral ankle alignment that did not require further intervention. All patients saved their limb and returned to independent ambulation. When performing free tissue transfer about the ankle, temporary spanning with a circular fixator is effective in preventing equinus deformity and provides a stable mechanical construct protecting the flap.