[Tissue flap repair strategy for severe defects of skin and soft tissue around the knee joints]

To explore selection and method of tissue flaps for the repair of severe defects of skin and soft tissue around the knee joints.

Fifty-four patients with wounds around the knee joints, all accompanied by exposure or necrosis of tendon or bone and exposure of prosthesis, were hospitalized in our burn center from June 2008 to December 2014. Five of them were with knee joint injury. After thorough debridement or tumor resection, the wound area ranged from 5 cm × 5 cm to 46 cm × 22 cm. Three patients were repaired with free latissimus dorsi myocutaneous flaps, 7 were repaired with modified sartorius myocutaneous flaps, 8 were repaired with gastrocnemius myocutaneous flaps, one was repaired with gastrocnemius muscle flap, two were repaired with posterior leg flaps combined with gastrocnemius muscle flaps, one was repaired with femoral biceps muscle flap combined with gastrocnemius muscle flap, 13 were repaired with reverse anterolateral thigh island flaps, two were repaired with reverse anterolateral thigh island flap combined with gastrocnemius myocutaneous flaps, two were repaired with superior lateral genicular flaps, 4 were repaired with reverse posterior thigh island flaps, 11 were repaired with saphenous artery flaps. Patellar ligament was reconstructed in 4 patients. The tissue flap size ranged from 5 cm × 5 cm to 38 cm × 19 cm. Some donor sites were sutured directly, and the others were closed by split-thickness skin grafting obtained from ipsilateral or contralateral legs.

Among 59 tissue flaps of 54 patients, 55 tissue flaps of 50 patients survived, while necrosis of the distal part was observed in 4 tissue flaps, including one saphenous artery flap, two reverse anterolateral thigh island flaps, and one free latissimus dorsi myocutaneous flap. Among them, 3 flaps with necrosis at the distal part healed after debridement followed by skin grafting, one myocutaneous flap healed by transplanting gastrocnemius myocutaneous flap. During the follow-up period of 6 to 36 months, the tissue flaps were in good appearance and texture, and knee joint function was good in most cases. In 4 patients the knee joint function was satisfactory after patellar ligament reconstruction, while stiffness was observed in 4 out of 5 patients with knee joint injury.

Free latissimus dorsi myocutaneous flaps are preferred to repair extensive defects around the knee joints. Reverse anterolateral thigh island flaps followed by saphenous artery flaps are preferred to repair wounds around the anterior knee. Wounds of the lateral knee are mainly repaired with reverse anterolateral thigh island flaps, and for small wounds the use of the superior lateral genicular flaps may be considered. Wounds of the medial knee can be repaired with modified sartorius myocutaneous flaps or saphenous artery flaps. Wounds of the posterior knee can be repaired with reverse posterior thigh island flaps or superior lateral genicular flaps. Wounds with severe infection or large space can be repaired with gastrocnemius myocutaneous flaps or muscle flaps or modified sartorius myocutaneous flaps. Anterolateral thigh flaps and gastrocnemius myocutaneous flaps are preferred in cases with indication of patellar ligament reconstruction.