Abstract: Objective To evaluate the clinical efficacy of long vascular pedicle peroneal artery perforator flap in repairing soft tissue defects of the lower knee joint. Methods Clinical data of 15 patients with lower knee joint wounds repaired by long vascular pedicle peroneal artery perforator flaps from January 2021 to December 2023 were retrospectively analyzed， including 10 males and 5 females， aged 18-67 years old. The flap harvest area ranged from 18 cm² to 40 cm². The donor area was directly sutured in 10 cases， and skin grafting was performed in 5 cases. The duration of the surgery， intraoperative bleeding， healing time， survival of flaps and skin grafts， postoperative complications， etc.， were recorded. The final followup evaluation was conducted using the British Medical Research Council （BMRC） sensory function assessment criteria and the Lower Extremity Functional Scale （LEFS）. Results All patients received an average follow-up of （20.6±6.6） months postoperatively. In 10 cases， the vascular pedicle of the flap was a full segment perforator， and in 5 cases， it was a full segment perforator plus part of the peroneal artery trunk. The pedicle length averaged（ 7.8±3.8） cm. All 15 cases of skin flap and 4 cases of donor area skin graft survived in the first stage， and 1 case of local necrosis of donor area skin graft was cured after dressing change. At the last follow-up， all flaps were soft in texture and had good blood circulation. The BMRC sensory assessment showed S2 level in 3 cases， S3 level in 10 cases， and S4 level in 2 cases， with an average two-point discrimination of（ 12.1±4.5） mm. There were no complications such as scar hyperplasia or contracture in the surgical area， and the walking function of the affected limb was normal， with an average LEFS score of （72.8±4.7） points. Conclusion The repair of skin and soft tissue defects in the lower part of the knee joint using a long vascular pedicle peroneal artery perforator flap is not only relatively simple and easy to perform， but also results in good recovery of lower limb function， with no deformities in the local appearance and high patient satisfaction， demonstrating good clinical efficacy.

Key words: Long vascular pedicle, &emsp, Peroneal artery flap, &emsp, Wound repair, &emsp, Knee joint