POSTERIOR INTEROSSEOUS FREE-FLAP - VARIOUS TYPES

The posterior interosseous artery is located in the intermuscular sept um between the extensor carpi ulnaris and extensor digiti minimi muscl es. The posterior interosseous artery is anatomically united through t wo main anastomoses: one proximal (at the level of the distal border o f the supinator muscle) and one distal (at the most distal part of the interosseous space). In the distal part, the posterior interosseous a rtery joins the anterior interosseous artery to form the distal anasto mosis between them. The posterior interosseous flap can be widely used as a reverse flow island flap because it is perfused by anastomoses b etween the anterior and the posterior interosseous arteries at the lev el of the wrist. The flap is not reliable whenever ther is injury to t he distal forearm or the wrist. To circumvent this limitation and to i ncrease the versatility of this flap, we hav refined its use as a dire ct flow free flap. The three types of free flaps used were (1) fascioc utaneous, (2) fasciocutaneous-fascia, and (3) fascia only. Described a re 23 posterior interosseous free flaps: 13 fasciocutaneous flaps, 6 f asciocutaneous-fascial flaps, and 4 fascial flaps. There were 13 senso ry flaps using the posterior antebrachial cutaneous nerve. The length and external diameter of the pedicle were measured in 35 cases. The le ngth of the pedicle was on average 3.5 cm (range, 3.0 to 4.0 cm) and t he external diameter of the artery averaged 2.2 mm (range, 2.0 to 2.5 mm). The hand was the recipient in 21 patients, and the foot in 2. All 23 flaps covered the defect successfully.