Thigh Length as the Most Consistent Anthropometric Parameter in Predicting the Size of Hamstring Tendon Autografts in Patients Undergoing Anterior Cruciate Ligament Reconstruction: A Cross-Sectional Study

Background Individual variability in the length and thickness of hamstring tendon autografts is a serious drawback in using these tendons for anterior cruciate ligament reconstruction (ACLR). In this study, we aimed to determine the correlation between the anthropometric parameters and the size of hamstring tendon autografts. Methods In a cross-sectional study, 52 male ACLR candidates were included. The length of semitendinosus and gracilis tendons and the diameter of single, doubled, and quadrupled tendons were measured. A graft sizing block device with an incremental size change of 0.5 mm (range 4.5-12) was used to measure the tendon graft diameter. The evaluated anthropometric parameters included age, gender, height, weight, BMI, thigh length and diameter, calf length, thigh-to-calf ratio, wrist diameter, and ankle diameter. A Pearson's or Spearman's correlation coefficient test was used for evaluating the correlation of anthropometric factors with graft characteristics. Results The mean age of the patients was 27.1 ± 6.4 years. The semitendinosus length was significantly correlated with the patient's height (r = 0.373, P = 0.007), thigh length (r = 0.364, P = 0.009), and calf length (r = 0.340, P = 0.015). The gracilis length was significantly correlated with thigh length (r = 0.278, P = 0.049). The mean quadruple diameter was 8.56 ± 1.15 mm (range 6.5-11). The quadruple diameter was significantly correlated with the thigh length (r = 0.283, P = 0.044). No other significant correlation was found between the tendons’ size and evaluated anthropometric parameters. Conclusion Thigh length was correlated with the semitendinosus length, gracilis length, and quadruple diameter. Therefore, it could be regarded as the most consistent and promising anthropometric factor in the prediction of hamstring autograft size.