Anatomic basis of local muscle flaps in the distal third of the leg.

Soft-tissue defects of the distal third of the tibia are considered to be the realm of free-tissue transfer. We have found clinically that several local muscles can be used reliably in this area. The purposes of this study were: (1) to evaluate the potential use of the local muscles for soft-tissue coverage in the lower third of the leg and (2) to obtain numerical data that could be used preoperatively in the selection of potential local muscle flaps. All potential muscles, excluding the gastrocnemius, plantaris, and popliteus, from 10 fresh frozen legs were examined and the following details recorded: (1) the distance above the medial malleolus that the muscle bellies ended (musculotendinous junction), (2) the distance between the medial malleolus and the distal end of the transposed flaps (reach), (3) the area of tibia that could be covered, and (4) the vascular supply to these muscles. The soleus, extensor digitorum longus and peroneus tertius, extensor hallucis longus, peroneus brevis, and flexor digitorum longus were found to be the most anatomically suited muscles for local transposition to selected lower-third defects. We have worked with these muscles clinically and have found them to be useful and reliable when chosen appropriately.