OBJECTIVETo explore the blood supply of the reverse arterial arch at the superior border of the hallucal abductor island flap and provide an anatomical basis for repairing fore foot skin defect using this flap.

METHODSThe constitution, course, distribution, and external diameter of the arterial arch at the superior border of the hallucal abductor, and the concomitant veins and nerves were observed on 12 sides of formaldehyde-fixed and 12 fresh adult foot specimens perfused with red latex. The surgical approach using the arterial arch at the superior border of the hallucal abductor for repairing fore foot skin defect were designed.

RESULTSThe arterial arch at the superior border of the hallucal abductor, constituted by the branch of the medial tarsal artery or the branch of the anterior medial malleolus artery anastomosed with the superficial branch of the medial basal hallucal artery or the branch of the superficial branch of the medial plantar artery or the all the four branches, functioned as the axis of the medial tarsal, the medialis pedis and the medial plantar. The external diameters of the anterior medial malleolus artery, the medial tarsal artery, the branch of the superficial branch of the medial plantar artery, and the distal arterial arch at the superior border of the hallucal abductor were 1.02∓0.03 mm, 0.73∓0.04 mm, 0.56∓0.02 mm, and 0.53∓0.14 mm, respectively. Most of the arteries (91.67%) had one concomitant vein with the external diameters of 1.01∓0.03 mm, 0.81∓0.04 mm, 0.57∓0.01 mm, and 0.61∓0.02, respectively, and only a small fraction of them (8.33%) had two concomitant veins.

CONCLUSIONSThe fore foot skin defect can be repaired using this flap supplied by the branch of the anterior medial malleolus artery and the medial tarsal artery, the superficial branch of the medial plantar artery, or all the three. The pivot point formed by the neck of the first metatarsal or metatarsophalangeal joint allows for long vessel pedicles and larger flap areas to increase the flexibility of surgery.