Free Flap Reconstruction for Gastrocnemius Muscle Necrosis to Avoid Above-Knee Amputation

Below-knee amputation is functionally superior to above-knee amputation, and preservation of the knee joint is essential for optimal mobility. In below-knee amputation, muscular coverage of the tibial stump and proper shaping for prosthesis fitting are key factors in functional recovery. If primary muscle coverage is not feasible, free flap reconstruction may be required to achieve these goals.

A 23-year-old man presented with gait disturbance due to complete peroneal nerve palsy, tibial nerve palsy, and disuse atrophy of the gastrocnemius muscle following a traffic accident at the age of 19 years. MRI suggested necrosis of the gastrocnemius muscle, which made primary coverage of the tibial stump unfeasible. To avoid the poor functional prognosis associated with above-knee amputation and to preserve the knee joint, we preoperatively planned and successfully performed a below-knee amputation with free latissimus dorsi musculocutaneous flap reconstruction. The patient achieved independent ambulation and was able to run with a prosthesis 10 months postoperatively. Three years after surgery, he remains free of complications and reports good functional outcomes.

This case highlights that below-knee amputation with free flap reconstruction should be considered in functionally independent patients for the preservation of activities of daily living (ADL) and maintaining long-term QOL.