Retrospective analysis of incidence of peroneal artery hypoplasia in 101 free fibula transfers and new classification of popliteal branch anomalies.

It is generally recognised by surgeons that there are anatomical variations of the popliteal artery and its branches, and knowledge of these has important clinical implications for fibula flap harvest. The aim of this study was to report our experience on 101 fibula free flaps, highlighting a new type of anatomical variation of the peroneal artery in a patient undergoing osteocutaneous fibula free flap for tibial reconstruction. During flap harvest, the peroneal vascular pedicle was shown to be hypoplastic and aberrant to its origin, branching between the proximal and medium third of the leg from the posterior tibialis artery with a diameter of 1mm. A modification of Kim's classification with the addition of a further "type IIID" group is suggested, to include peroneal artery hypoplasia or aplasia. This is an uncommon case of a rare infrapopliteal branching pattern that was undetected clinically and sonographically, exposing both the surgeon and patient to high risk of flap failure and/or leg ischaemic complication. Surgeons conducting free fibula transfer surgery should be aware of such a possibility as well as other variations, and could consider performing routine angiographic study on the donor limb, or they may be skilful enough to apply instant tricks to enable them to conduct the procedure safely.