[Clinical effects of retrograde anterolateral thigh flaps in repairing anterior knee joint wounds under the concept of precise flap surgery].

Objective: To introduce the methods of retrograde anterolateral thigh flaps in repairing anterior knee joint wounds under the concept of precise flap surgery and to explore the clinical effects. Methods: A retrospective observational study was conducted. From August 2014 to March 2022, 7 patients with anterior knee joint wounds were treated with retrograde anterolateral thigh flap under the guidance of the concept of precise flap surgery in the 920^th Hospital of Joint Logistic Support Force of PLA. Among them, 6 were males and 1 was female, aged 36 to 66 years. The sizes of wounds were 7 cm×5 cm to 15 cm×11 cm after debridement. All the patients were performed with computed tomography angiography (CTA), the donor and recipient sites were evaluated according to the precise flap surgery method, and the optimal pedicle, perforator, and pivot of flaps were chosen. The flap sizes were 10 cm×6 cm to 20 cm×9 cm, and all the donor sites of flaps were sutured directly. The consistency of the intraoperative exploration with preoperative CTA was observed. The flap survival and occurrence of complications were observed after surgery. The color, appearance, texture, and occurrence of complications were followed up. At the last follow-up, the blood supply of flaps was evaluated using the blood circulation evaluation indicators of Chinese Medical Association Hand Surgery Branch's trial criteria for digital replantation function evaluation, and the function of knee joint was evaluated using knee joint scoring system of hospital for special surgery. Results: The flap condition of the intraoperative exploration was completely consistent with that of preoperative CTA. The flaps survived completely after surgery in 6 patients, while necrosis at the edge of the flap occurred in 1 patient, which healed after dressing change. All the flaps were hyperperfused after surgery, and the color of the flaps gradually became normal after 1 week. Follow-up of 7 to 44 months showed that the color, appearance, and texture were well in all the patients, while local osteomyelitis at the proximal tibia occurred in 1 patient. At the last follow-up, all the 7 patients had excellent blood circulation; the function score of knee joint was 69 to 91, which was evaluated as excellent in 3 cases, good in 3 cases, and fair in 1 case. Conclusions: The retrograde anterolateral thigh flap has large variations, and the application of precise flap surgery method can accurately understand the variations before surgery, guide the design and cutting of the flaps, thus achieving precise repair of anterior knee joint wounds, with good repair outcome.