Investigating the Magnetic Resonance Imaging Cross-sectional Area That Best Correlates with Intraoperative Hamstring Autograft Size

Background: Hamstring tendon autografts are widely used for anterior cruciate ligament (ACL) reconstruction, but preoperative prediction of graft diameter remains a clinical challenge. Magnetic resonance imaging (MRI)-based cross-sectional area (CSA) measurements are increasingly being used to estimate graft adequacy. Objective: To determine which MRI-based CSA measurement level most accurately correlates with intraoperative hamstring autograft diameter in ACL reconstruction. Methodology: A prospective observational study was conducted on 41 patients aged 20–45 years undergoing ACL reconstruction. MRI CSA of the semitendinosus and gracilis tendons was measured at two anatomical levels: anteroposterior (AP) and joint line. Correlation with intraoperative graft size was assessed using Pearson and Spearman coefficients. MRI data were analyzed using Horos, and statistical analysis was performed in JASP software. Results: The mean CSA at the AP level (19.63 mm²) was higher than at the joint line (16.55 mm²). The AP CSA showed the strongest correlation with intraoperative graft diameter ( r = 0.858, P < 0.001), followed by joint line CSA ( r = 0.625). The average intraoperative graft diameter was 8.48 mm. Conclusion: MRI-based CSA measurement at the AP level has proven to be a reliable, noninvasive predictor of intraoperative hamstring graft diameter, aiding in surgical planning and graft sufficiency prediction.