Clinical and knee anatomic risk factors for anterior cruciate ligament injury

BACKGROUND: We investigate the correlation between clinical or knee anatomic factors with noncontact anterior cruciate ligament (ACL) injuries and identify potential risk factors for ACL injuries. METHODS: A retrospective study was conducted, 108 patients who received magnetic resonance imaging (MRI) of the knees and identified with noncontact ACL injuries between January 2020 and July 2021 were included in this study. Furthermore, each noncontact ACL-injured patient with no meniscus tears was matched with 2 controls with radiologi-cally normal knees at the same period according to gender and age. MRI studies were analyzed by 2 independent, blinded observers measuring the medial posterior tibial slope (MTS), lateral posterior tibial slope (LTS), notch width and notch width 2/3. The associations between different clinical or knee anatomic factors and ACL injuries were analyzed. RESULTS: Based on the analysis, the MTS (OR=0.853, P=0.013), LTS (OR=0.658, P<0.001), notch width (OR=.48, P=0.014) and Body Mass Index (BMI) (OR=0.881, P=0.012) were the independent risk factors correlated with non -contact ACL tears. These factors had comparable accuracy on predicting noncontact ACL tears (the AUC of those factors were 0.625, 0.793, 0.596 and 0.594, respectively). The cutoff values of those factors were 1.57 degrees, 11.84 degrees, 27.95mm and 23.45 kg/m2, respectively. CONCLUSIONS: In summary, we identified MTS>1.57 degrees, LTS>11.84 degrees, notch width< 27.95mm and BMI >23.45 kg/m2 as independent risk factors for noncontact ACL tears.