Free musculofasciocutaneous medial plantar flap for reconstruction of thenar defects.

Functional reconstruction of thenar skin defects complicated by muscle loss is possible by transfer of a medial plantar flap with the underlying abductor hallucis muscle. Three patients with severe flexion-adduction contractures of the thumb due to gunshot injuries were reconstructed by using this musculofasciocutaneous flap. At surgery, after release of the skin contractures, all dysfunctional fibrotic muscles were excised. A medial plantar flap and the abductor hallucis muscle were dissected together; the motor branch of the abductor hallucis was preserved by intraneural dissection and sutured to the thenar motor branch of the median nerve. The muscle ends were sutured across the defects of the thenar muscles. All flaps survived without any loss at follow-up of 6-9 months. The flaps adapted to the thenar region completely by providing sufficient thenar bulk and a good skin colour match with palmar skin. Electromyography of the transferred muscle showed an interference pattern with an amplitude of about 200 mV in two cases and 100 mV in one case. Clinically, these findings were supported by voluntary opposition of the thumbs with good strength.