Patient Height may Predict the Length of the Anterior Cruciate Ligament: A Magnetic Resonance Imaging Study

PURPOSE: The purpose of this study was to measure the length and width of anterior cruciate ligament (ACL) tibial footprint using magnetic resonance imaging (MRI) and to evaluate correlation between patients’ weight and height with the tibial footprint size. METHODS: In total, 207 eligible patients underwent MRI scanning from June 2018 to June 2020. One hundred seventeen knees from patients aged 18 to 40 years old with intact ACL were included in this study. Data of weight, height, body mass index (BMI) from physical examination and tibial footprint length and width from MRI were obtained. Relationship of ACL tibial footprint length <14 mm and association between ACL tibial footprint sizes of MRI with height, weight, and BMI were analyzed. RESULTS: The ACL tibial footprint length and width were, respectively, 11.9 ± 1.8 mm and 10 ± 1.5 mm. Proportion of ACL footprint <14 mm in length was 89.7%. Patient height ≥170 cm was the best predictor of ACL tibial footprint length <14 mm (P = .025). There was a statistically significant relationship between the height of the patients and the length of the ACL tibial footprint. The length of the ACL tibial footprint could be predicted by the formula: length = −7.362 + 11.48 × (height in meters). CONCLUSION: The height of the patients may predict the length of the ACL tibial footprint. Although patient’s age, sex, and BMI correlate poorly with ACL tibial footprint width, there was no correlation between patient’s weight and ACL tibial footprint size. CLINICAL RELEVANCE: Before ACL reconstruction surgery, an estimation of ACL tibial footprint size might aid in the graft harvesting preparation.