[Anterior interosseous flap].

An anatomical study which was carried out on 44 upper limbs of fresh cadavers has enabled us to describe a new flap based on the superior perforating branch of the anterior interosseous artery: "the anterior interosseous flap". The anterior interosseous artery participates in the vascularization of the dorsal aspect of the distal two-third of the forearm by providing two perforating branches, "the superior and the inferior perforating branches". The superior perforating branch of the anterior interosseous artery, pedicle of the flap, perforates the interosseous membrane 10 +/- 2 cm above the radio-carpal joint and runs in the septum between the extensor pollicis longus and brevis muscles accompanied by two venae comitantes. The calibre of the artery at its origin varies from 0.9 to 1.5 mm. During its course, the artery gives 5 to 7 septocutaneous branches to reach the overlying skin in the posterior aspect of the distal two-thirds of the forearm. It also gives 3 to 5 osseous branches spreading over the dorsal aspect of the distal third of the radius and several muscle branches to the abductor pollicis longus, extensor pollicis longus and brevis, extensor indicis and extensor digitorum muscles. The inferior perforating branch of the anterior interosseous artery generally perforates the interosseous membrane 4 to 5 cm above the radio-carpal joint. After giving a medial branch which anastomoses with the posterior interosseous artery (in 42 out of 44 cases) the inferior perforating branch of the anterior interosseous artery always runs distally to join the dorsal vascular network of the wrist which is rich enough to produce a retrograde arterial blood flow. This flap can be used as an island flap (with a retrograde or a direct blood flow) or a free flap. The surgical procedure of the retrograde island flap consists in raising the cutaneous or compound flap based on the superior perforating branch, division of the interosseous membrane and ligature of the anterior interosseous trunk proximally. The flap is vascularized by a retrograde blood flow through the dorsal (or volar or both) vascular network of the wrist. Theoretically, the most distal point of rotation of the flap is located at the level of the luno-capitate joint and the pedicle is long enough to allow the most distal point of the flap to reach the DIP joint of the finger.(ABSTRACT TRUNCATED AT 400 WORDS)