OBJECTIVETo report an anatomical basis for the posterior tibial artery intermuscular septum branches island flaps and its clinical value.

METHODSThe origin,course, number, caliber and distribution of the posterior tibial artery intermuscular septum branches were studied in 10 adult cadavers(20 legs). 10 cases of homonymy and opposite side ankle and adjacent soft tissue defects with posterior tibial artery intermuscular septum branches island flaps, aged 20-50 years. Free skin transplantation on the donor sites.

RESULTSThe posterior tibial artery gives off 2-7 intermuscular septum branches. Its external diameter was about 0.4-1.8 mm,and the length was about 0.3-4.5 cm. The area of flaps was 7 cm x 6 cm - 20 cm x 8 cm in the group. All the flaps were survived except 1 with partial necrosis in the distant part(3 cm x 1 cm) of the flap. 7 cases were followed up two months to three years. The color, texture and appearance of the flaps were good.

CONCLUSIONSThe kind of flap has reliable blood supply, the scope of repairing was wide; avoidance of sacrificing the major artery; the flap was easy to be dissected. It was one of the ideal flaps to repair the ankle and adjacent soft tissue defects.