Free Chain-Linked Fillet Flaps From a Contralateral Chopart Amputation for Reconstruction of an Extensive Lower Extremity Defect: A Case Report and Literature Review

Free fillet flap reconstruction transfers composite tissue from an unsalvageable limb to repair a separate defect. We report a case of free fillet flaps based on the posterior tibial artery (PTA) and anterior tibial artery (ATA). A 41-year-old man was crushed under a truck; his right leg suffered an open tibia and fibula fracture (Gustilo IIIB) with extensive soft tissue loss, while his left foot was amputated at the tarsal level. He initially underwent Chopart-level amputation of the left limb, which was subsequently revised to a below-knee amputation. Two free fillet flaps were harvested from the amputated limb: one based on the PTA (15 × 13 cm) and the other based on the ATA (20 × 8 cm). Two chain-linked fillet flaps via flow-through anastomosis were used to cover the soft tissue defect exposing the right tibia. Postoperatively, partial necrosis occurred in the ATA-based fillet flap, which healed after reoperation. The patient regained mobility with a prosthesis. Free chain-linked fillet flaps harvested from a limited amputation segment are a feasible and useful option for reconstructing complex soft tissue defects without additional donor site morbidity.