The role of the intercondylar notch’s morphology in anterior cruciate ligament injury

Background The relationship between anterior cruciate ligament (ACL) injury and the morphology of the intercondylar notch remains unclear. The purpose of this study was to determine which morphometric characteristics of the intercondylar notch contribute to the ACL injury using MRI images. Methods A retrospective study was conducted in which 107 knee joint magnetic resonance images (MRI) of healthy, active males were compared. The patients were distributed between 55 ACL-injured patients and 52 matched control subjects. A descriptive and analytical study studied the effects of the following variables on the risk of ACL injury: notch width index; notch shape index notch; notch angle, notch height index on the axial and the coronal planes (axial NWI, coronal NWI, axial NSI, coronal NSI, axial NA, coronal NA, axial NHI and coronal NHI respectively), the Blumensaat alpha angle and the shape of the notch as described by Hirtler. A receiver operating characteristic (ROC) analysis was conducted for the significative parameters to determine their cut-off values. Results The coronal NWI (p = 0.048, cut-off = 0.25), the axial NSI (p = 0.004, cut-off = 0.43) and the axial NA (p = 0.048, cut-off = 47°) were significant risk factors for ACL injury, the other studied parameters were not associated with increased risk of ACL injury. Conclusions The coronal NWI, the axial NSI and the axial notch angle are independent anatomical risk factors for ACL injury and express a narrow intercondylar notch in young active males.