The lateral arm flap is a thin, innervated, fasciocutaneous flap with a constant vascular anatomy. Although brief reports of the anatomy and clinical use of the flap were available in 1982,1,2,3 the first comprehensive study was published by Katsaros et al. in 1984.4 The vascular anatomy of this flap is based on the posterior radial collateral artery (PRCA), a branch of the profunda brachii artery. Another branch of this artery, the anterior radial collateral artery, is variable and of small caliber, and does not contribute to the flap's vascular supply. The lower lateral cutaneous nerve of the arm, arising from the radial nerve and piercing the triceps muscle belly, innervates this flap.5 The posterior cutaneous nerve of the forearm also arises from the radial nerve and courses through the flap, continuing distally to supply the lateral border of the forearm.5

Technical Considerations

The lateral arm flap is suitable for coverage of soft tissue defects of the dorsal and volar surfaces of the hand, forearm, foot, anterior tibial surfaces, and face. Because the undersurface of the flap is fascial, it is an excellent choice for covering tendons or for situations in which tendon reconstruction is anticipated. The flap is relatively thin and often free of hair. For this reason, it may also be used for reconstructing intraoral defects. Its color and thinness also make it useful for facial reconstruction. If a very thin flap is required, as in reconstruction of a gliding surface, the fascia and its vascular pedicle may be harvested without the overlying skin and fat. In this way, a large fascial flap is available with primary closure of the donor defect. Because the flap is innervated by the lower lateral cutaneous nerve, it may be used for sensory cutaneous reconstruction. In many cases, a second team may simultaneously harvest the flap, thus greatly reducing the operative time.

The major landmarks to be identified during flap harvest are the insertion of the deltoid muscle upon the humerus and the lateral epicondyle of the humerus. The flap lies midway between these two structures. Dissection may be accomplished with the patient supine or in a lateral decubitus position. The shoulder may be adducted or abducted. A narrow sterile tourniquet placed as high as possible about the arm provides a bloodless field.

next page...