Traumatic Complete Loss of Knee Extensor Mechanism and Its Reconstruction With a Fresh-frozen Patellar Allograft With Patellar and Quadriceps Tendon.

We report on an 18-year-old female who sustained complete loss of her knee extensor mechanism (patella, quadriceps and patellar tendon) due to a motorbike injury with severe soft tissue loss of the ventral aspect of the knee and subsequent infection. After infection control and successful latissimus dorsi free flap surgery, reconstruction of the knee extensor mechanism was performed using a fresh frozen extensor mechanism allograft with patella, quadriceps- and patellar tendon and integrated tibia tuberosity fragment. After a follow-up of 18 months, there was infection free integration of the allograft with a range of motion 0-0-90° (extension/flexion) and pain free gait.