Objective:To investigate the clinical effect of turbocharged large free anterolateral thigh flaps (ALTF) by anastomosis with a superior perforator of the flap in reconstruction of large soft tissue defects of limbs.Methods:From June 2017 to June 2021, 6 patients with large soft tissue defects of limbs with exposed joints and tendons were treated in the Department of Hand and Foot Surgery of the Affiliated Hospital of Qingdao University with turbocharged large free ALTFs. The pressurised blood supply of ALTF was achieved by anastomosing a superior perforating branch carried in the flap. Such large and turbocharged ALTFs were used to repair large soft tissue defects with exposed joints and tendons in limbs. Of the 6 patients, there were 4 males and 2 females, and aged 32-60(46.0±8.1) years old. Cause of injury: 5 by traffic accident and 1 by machine crush. Four patients had soft tissue defects in lower limbs: 2 with open tibia and fibula fractures, 1 had patellar defect and fibula fracture, and 1 associated with fibula fracture. The other 2 patients had soft tissue defect in upper limbs with bone and tendon exposed but without fracture. The sizes of wound were 25.0 cm×12.0 cm-35.0 cm×19.0 cm. In the primary surgery, Vacuum sealing drainage (VSD) was applied. In the second stage, free ALTFs were used to cover the wound. The area of flap incision was increased by anastomosing the superior perforators and as the consequence, the size of flaps was achieved to 26.0 cm×13.0 cm-36.0 cm×15.0 cm. Donor site of 6 cases were reduced by direct suture, and the remaining wound was covered by free skin graft. Postoperative follow-ups were conducted at outpatient clinic reviews at 1, 2, 3 and 6 months after surgery, and followed by telephone or WeChat interviews. The results of the operation were evaluated according to the appearance, texture and sensory recovery of the flap.Results:All 6 flaps survived and the patients completed the postoperative follow-up that lasted for 6-24 (16.7±5.0) months. No necrosis of flap occurred after surgery. The appearance and texture of the flaps were satisfactory without wear and tear. Sensation recover was evaluated by the standered of British Medical Research Council (BMRC), 4 patients recovered to S 3 and 2 patients to S 2. The Mayo score of the elbow joint was good in 2 patient with upper extremity injuries. Of the other 4 patients with lower limb injuries, the knee function evalued by Hospital for Special Surgery(HSS) score were excellent in 3 patients and good in 1 patient, and the American Orthopedic Foot and Ankle Societ(AOFAS) ankle-hind foot function score was excellent in 2 patients and good in 2 patients. There was no infection or function loss at all donor sites. Conclusion:The perforator of an ALTF is relatively constant, and the flap can partially restore sensation. The superior perforator is reliable and the incision area of the flap can be enlarged by anastomosing the superior perforator vessels. It is a better way to reconstruct a large soft tissue defects in limbs.