Gracilis Functional Free Muscle Transfer for Reconstruction of Entire Extensor Mechanism of Knee

Abstract

Loss of the entire extensor mechanism of the knee presents a major reconstructive challenge. We encountered a patient who was missing the patellar tendon, patella, and quadriceps tendon following a remote trauma. A prior attempt at allograft reconstruction failed due to infection and dehiscence at the allograft-muscle connection. To avoid an allograft, we reconstructed the entire knee extensor mechanism with an ipsilateral functional free gracilis transfer, maintaining the enthesis at the tibia, rerouting the muscle across the anterior knee, and attaching the origin to the fascia lata. We vascularized the muscle with the descending branch of the lateral circumflex femoral vessels and innervated the muscle with a motor branch of the femoral nerve. The transfer was successful, with the patient able to ambulate without a brace by 6 months and to perform squats by 9 months. Complications commonly seen with allograft were obviated, and functional recovery was excellent.