A Case of Nonisland Pedicled Foot Fillet Flap for Below-Knee Amputation Stump Wound: Treatment Option for Compartment Syndrome after Fibular Free Flap Surgery
A 66-yr-old man, who had developed compartment syndrome after a fibular osseous free flap transfer from the left leg to the mandible on April 24, 2013, was referred to our department on postoperative day 26. The donor site, which had been closed primarily, was opened on postoperative day 7. Evaluation showed a 20-cm fibular defect, a residual 8-cm proximal fibular segment, an intact tibia, and extensive necrosis in all compartments of the leg. The foot was well vascularized through the posterior tibial vessels but was insensate. Treatment included several debridements with irrigation in the operation room for 3 weeks. A suction pressure wound therapy system was applied on the wound and changed every 3 days.\nAfter the wound improved, 3 treatment options were considered including above-knee amputation, below-knee amputation, or flap reconstruction without amputation. Considering the patient's age, his general condition, and the wound condition, we selected a below-knee amputation to preserve knee joint function. A foot fillet flap was considered to reduce donor site morbidity, but dissection of the posterior tibial vessels was not possible because of inflammation, scar formation, and adhesion to surrounding tissue. Therefore, a nonisland pedicled flap including skin and soft tissue in the pedicle was planned.\nAt 47 days after the initial fibular free flap transfer, below-knee amputation and coverage of the stump were performed under general anesthesia with loupe magnification, a pneumatic thigh tourniquet without limb exsanguinations. After devitalized tissue in the wound was debrided completely, the tibia was cut 13.5 cm distal to the tibial tuberosity. The dorsum of the foot was incised from the distal margin of the wound near the lateral ankle to the wound at the dorsum of the foot (). The toes were amputated through the metatarsophalangeal joints. The remaining skin and soft tissue, including the vascular pedicle, were elevated at the subperiosteal level. The distal tibial and fibular segments and all tarsal and metatarsal bones were removed. Dense fibrous tissue at the plantar surface of the foot, large tendons, and volar plates of the metatarsophalangeal joints were excised. The intrinsic muscles of the foot were preserved, and the posterior tibial neurovascular bundle was not debulked (). The flap was rotated 180° and folded, and the posterior plantar part of the flap was placed at the weight bearing aspect of the distal tibia. The anterior plantar part of the flap was placed in the soft tissue defect at the posterior calf, and the calf part of the flap was placed at the soft tissue defect of the anterior calf below the patella. After insertion of suction drainage tubes, the flap was sutured to the wound and remaining flap margins (). Complete survival of the flap was achieved and the knee joint was mobilized early.\nAt 84 days after below-knee amputation and flap coverage, a debulking procedure was performed to reduce the excess volume of the healed flap. The posterior tibial neurovascular pedicle was inevitably transected and immediate neurorrhaphy of the posterior tibial nerve was performed. At 2 months after the debulking procedure, the patient noted tingling sensation at the flap. Follow-up at 7 months after below-knee amputation and nonisland pedicled foot fillet flap showed that the flap was well healed with improving sensation to the skin flap and the patient was satisfied with the result ().