Association of lateral femoral condyle index, notch width index, and risk of anterior cruciate ligament injury – A retrospective study

Objectives: The bony morphology of the distal femur and proximal tibia plays a crucial role in knee biomechanics and has been linked to an increased risk of anterior cruciate ligament (ACL) rupture. This study evaluates the influence of lateral femoral condyle index (LFCI) and intercondylar notch dimensions using the notch width index (NWI) on primary ACL injury. Materials and Methods: A retrospective comparative study including 164 patients was conducted. 82 patients with primary ACL rupture were compared with 82 control patients who underwent magnetic resonance imaging (MRI) for isolated meniscal pathology or anterior knee pain. LFCI and NWI were measured on MRI. Statistical analysis, including receiver operating characteristic (ROC) curve analysis, was performed to determine the predictive value of these indices. Results: The mean LFCI was significantly lower in the ACL group (0.70) compared with controls (0.75) ( p = 0.004). ROC analysis demonstrated an area under the curve of 0.75 with a cut-off value of 0.745 (81% sensitivity and 65% specificity). NWI showed no significant difference. Conclusion: Reduced LFCI appears to be associated with increased risk of ACL rupture, while NWI was not an independent predictor. As a retrospective observational study, our findings highlight the potential role of MRI-based morphological assessments in identifying high-risk individuals, though further prospective research with randomization is needed to validate these results.