Peroneal nerve compression by lateral gastrocnemius flap.

Lateral gastrocnemius muscle flaps are reliable flaps routinely used to cover defects in the lower thigh, the knee, and the upper third of the tibia. Peroneal neuropathy following lateral gastrocnemius flap has been described previously and mostly attributed to intraoperative nerve injury. However, compression of the nerve by the flap itself has not been reported. A 56-year-old female developed right common peroneal nerve palsy 10 months after a lateral gastrocnemius flap rotation for knee prosthesis coverage. Surgical exploration found a common peroneal nerve neuroma under a compressive band formed by the lateral fascial edge of the rotated gastrocnemius muscle. The motor nerve of the flap was not denervated. When stimulated, muscle contracted and compressed the common peroneal nerve underneath. Excision of the lateral fascia and selective motor denervation were performed. Postoperatively, the patient's symptoms improved. To prevent compressive common peroneal neuropathy from lateral gastrocnemius rotational flaps, we recommend fascial excision from the lateral aspect of the muscle and selective motor denervation.