Reconstruction of the Knee Extensor Mechanism Using a Semitendinosus Tendon Graft and a Free Vascularized Latissimus Dorsi Musculocutaneous Flap for Complete Extensor Mechanism Loss With an Extensive Soft Tissue Defect: A Case Report

A 58-year-old male sustained an injury that resulted in complete loss of the knee extensor mechanism, with an extensive soft tissue defect on the anterior aspect of the knee. Reconstruction of the knee extensor mechanism using an autologous semitendinosus tendon graft and coverage of the soft tissue defect using a free vascularized latissimus dorsi musculocutaneous flap were performed. The patient returned to his previous work six months after surgery without difficulty, except for a slight feeling of exhaustion when going up and down stairs. Recovery of hamstring muscle strength was sufficient, whereas quadriceps muscle strength remained less than 30% compared with the contralateral side even two years after surgery.