Does harvesting of the semitendinosus tendon really spare the gracilis in pediatric anterior cruciate ligament reconstruction?

PURPOSE: The use of isolated semitendinosus tendon for Anterior Cruciate Ligament Reconstruction bears several advantages and is popular worldwide. It assumes that the gracilis tendon is spared. The aim of the study was to measure the surface area of the gracilis tendon in children who had undergone arthroscopic reconstruction of the anterior cruciate ligament using a semitendinosus tendon graft. Our hypothesis was that the gracilis tendon may be unintentionally and iatrogenically sectioned due to the anatomical proximity and the small size of the patients. METHODS: Fifty patients who had undergone a magnetic resonance imaging preoperatively and postoperatively at 1 year from the surgery and who had been operated between January 2017 and March 2019 were included in this prospective series. The surface area of the gracilis tendon was measured on fat-saturated T2-weighted axial views at the widest point of the medial epicondyle of the femur. Age, sex, body weight, and height were documented. RESULTS: One hundred magnetic resonance imaging of 50 knees were reviewed, from 34 boys (68%) and 16 girls (32%). The mean age was 14.5 years (10–18). The gracilis was visualized in all cases at 1 year postoperatively. The average tendinous surface area of the gracilis before the surgical procedure was 7.13 mm(2) versus 8.73 mm(2) at 1 year, representing an increase of 1.6 mm(2) (p = 0.0003). CONCLUSIONS: This study demonstrated that harvesting of the semitendinosus for the purpose of Anterior Cruciate Ligament Reconstruction was a safe technique that preserves the gracilis. LEVEL OF EVIDENCE: III.