Preoperative Magnetic Resonance Imaging Cross-Sectional Area for the Measurement of Hamstring Autograft Diameter for Reconstruction of the Adolescent Anterior Cruciate Ligament

PurposeWe conducted this study to determine if preoperative magnetic resonance imaging (MRI) cross-sectional area measurements would correlate with intraoperative graft size in hamstring anterior cruciate ligament (ACL) reconstructions.MethodsWe retrospectively reviewed ACL reconstructions performed by a single surgeon using a quadruple-looped hamstring allograft. Preoperative MRI axial images were used to determine the combined cross-sectional area of the semitendinosis and gracilis tendons. These cross-sectional areas were correlated to the intraoperative graft size.ResultsWe found a strong correlation between the MRI cross-sectional areas and graft size. If the combined cross-sectional areas were ≥18mm2, there was an 88% probability of obtaining a graft of sufficient size at the time of surgery.ConclusionsWe conclude that our technique is a reliable option to assist the surgeon with preoperative determination of graft size. This is valuable to the orthopaedist to more accurately discuss graft options with the patient and improve preoperative preparation with respect to graft choice. Level of Evidence: Level II, development of diagnostic criteria on the basis of consecutive patients with universally applied gold standard.