Objective:To investigate the feasibility and clinical efficacy of anterolateral thigh chimeric perforator flap in repair of large area soft tissue defects around the knee joint.Methods:From January, 2015 to October, 2019, 9 patients with large area soft tissue defects around the knee joint were treated. All patients had different degrees of defect in knee joint capsule and joint opening. Before operation, the width of the flap was determined by "skin lifting and kneading test", and the location of perforators in anterolateral femoral region was confirmed and marked with the assistance of HHD detector. According to the size and shape of the wound surface, single leaf or lobulated perforator flap was designed based on the principle that the donor site should be closed directly. The minimum size of the flap was 14.0 cm×5.0 cm, there was 1 case of lobulated flap with the largest area, respectively was 17.0 cm×9.0 cm and 18.0 cm×8.5 cm. The chimeric tissue flap(muscle flap or fascia lata flap) was taken according to the location and severity of joint opening. The grafted tissue flap was used to fill the articular cavity, the flap was used to repair the wound of knee joint, the blood supply of the flap was reconstructed, and a drainage catheter was placed in the cavity of knee joint. The recovery follow-up conducted in outpatient department.Results:All flaps survived without vascular incident. The recipient site of flap in 1 patient was not thoroughly washed and drained, and there was more exudation. After dressing change and drainage, the rest recipient areas of the flap were healed in stage I. All patients entered 3 to 36(average 12) months of follow-up. The appearance and function of recipient area recovery were satisfactorily. Only a linear scar remained in donor site.Conclusion:Anterolateral thigh chemeric perforator flap is ideal for repairing large soft tissue defects around the knee joint.