Topographical anatomy of the anconeus muscle for use as a free flap.

A small triangular anconeus muscle in the depth of the elbow is a continuation of the triceps brachii muscle and takes part in extension of the forearm. It is utilized clinically by certain surgeons as a muscle pedicle flap to cover defects around the elbow. However, there has been no report of an anconeus muscle free flap. This study provides the detailed anatomy of the anconeus muscle to encourage a safer utilization of it as a free flap. Thirty-four cadaveric upper extremities were treated by injections of colored latex, lead oxide, and methylene blue into the axillary artery. The average size of the muscle was 73.11 +/- 10.32 mm x 27.39 +/- 3.29 mm and the total area was 2002.48 +/- 33.95 mm2. The muscle received its blood supply from three sources: recurrent posterior interosseous artery, medial collateral artery, and posterior branch of the radial collateral artery. The recurrent posterior interosseous artery was constantly present. Its average outer diameter was 1.11 +/- 0.32 mm and its average length was 29.05 +/- 9.29 mm. The anconeus muscle free flap is large enough to cover a defect of 25.65 cm2 in either the hand or forearm, and the recurrent posterior interosseous artery and venae comitantes are suitable for microvascular anastomosis.