Abstract: Objective　To discuss the clinical effects of the true anastomosis connections between  the sural neuro-vascular flap and outcomes of the flap for reconstructing the soft tissue defect in the forefoot. Methods　Five amputated lower limbs were obtained from 5 patients with recurrent malignant bone tumor in the middle and/or upper femur. After being acquired, these specimens were irrigated and then perfused with a barium sulfate/red latex mixture immediately. The integuments of these limbs were stripped and radiographed. Anatomic observation focused on the true anastomosis connections within the arterial chain around the sural nerve, among the peroneal perforators and between these perforators and the arterial chain. Fifty-two sural neuro-vascular  flaps were used to perform the soft tissue defects in the forefoot.　Results　The arterial chain surrounding the sural nerve was linked by true anastomoses from the intermalleolar line to popliteal crease. The distal 2 to 3 peroneal perforators were connected by true anastomoses of their longitudinal branches. Forty-two flaps survived. Partial necrosis occurred in 10 (19.2%) flaps, the remnant defects were successfully performed by secondary suture (n=1), skin grafting (n=8) and local flap transposition (n=1).　Conclusions　The true anastomosis connections within the arterial chain around the sural nerve, among the distal 2 to 3 peroneal perforators and between these perforators and the arterial chain, are the vascular anatomical basis of the sural neuro-vascular flap which survives with greater length. This flap is a better option for reconstruction of the soft tissue defect in the forefoot.

Key words: Surgical flap, 　Sural nerve;　 Forefoot;　 True anastomoses