ObjectiveTo investigate clinical application of the free peroneal artery perforator flap in soft tissue defect of foot and ankle.MethodsThe clinical data of 18 patients with soft tissue defects of foot and ankle who were repaired with free peroneal artery perforator flaps between March 2019 and March 2020 were retrospectively analyzed. Among them, there were 11 males and 7 females; the age ranged from 21 to 58 years, with an average age of 45 years. The defect was located in the ankle in 2 cases, in the hindfoot in 4 cases, in the midfoot in 5 cases, and in the forefoot in 7 cases. The causes of injury included 11 cases of traffic accident, 4 cases of machine injuries, 3 cases of infection and necrosis after internal fixation. The time from injury to flap repair was 12-48 days, with an average of 24 days. The range of wound was 3 cm×3 cm to 15 cm×8 cm, and the range of skin flap was 4 cm×3 cm to 16 cm×9 cm. The flap harvesting time, operation time, intraoperative blood loss, and complications were recorded; the flap survival and patient satisfaction were observed during follow-up; and the American Orthopaedic Foot and Ankle Society (AOFAS) foot function score was used to evaluate the foot function.ResultsThe flap harvesting time was 15-33 minutes (mean, 22 minutes); the operation time was 120-160 minutes (mean, 150 minutes); the intraoperative blood loss was 90-180 mL (mean, 120 mL). There were 3 cases of vascular crisis after operation, including 2 cases of arterial crisis, which survived after vascular exploration and vein graft repair; 1 case of venous crisis, partial necrosis of the skin flap, and skin grafting to cover the wound after repeated debridement. The remaining 15 skin flaps survived completely. All patients were followed up 6 months. The skin flaps were in good shape without obvious bloat. According to the AOFAS foot function score, 5 cases were excellent, 10 cases were good, and 3 cases were fair. The excellent and good rate was 83.3%.ConclusionThe free peroneal artery perforator flap is easy to harvest, the shape and size of the flap are easy to design, and it does not damage the main blood vessels of the limb. The appearance and function of the limbs are satisfactory after operation. It can be widely used in the repair of soft tissue defects of the foot and ankle.