TYPE A INTERCONDYLAR FOSSA CONFIGURATION SIGNIFICANTLY INCREASES ACL RUPTURE RISK: A MORPHOMETRIC MRI STUDY.

Abstract

Background: Anterior cruciate ligament (ACL) rupture is a prevalent and debilitating injury, particularly among active individuals. Morphological characteristics of the femoral intercondylar fossa have been hypothesized to influence susceptibility to ACL injury, with specific shapes such as the Type A (narrow, steep-sided) notch potentially predisposing the ligament to mechanical impingement and rupture.

Purpose: To evaluate the association between intercondylar fossa morphology and the presence of ACL rupture using MRI-based morphometric assessment.

Methods: This retrospective cross-sectional study included 80 participants (40 with confirmed ACL rupture and 40 controls with intact ACL) who underwent knee MRI at the University Clinical Center of Kosovo. Intercondylar fossa shape was classified into three types-A, U, and W-based on standardized coronal and axial MRI views analyzed using Mimics software. Statistical analysis was conducted using SPSS, including chi-square testing, logistic regression, and ROC curve analysis.

Results: Type A fossa morphology was significantly more prevalent among ACL-ruptured patients (p<.001). Binary logistic regression revealed that individuals with a Type A fossa had an 8.76-fold increased risk of ACL rupture (OR=8.76; p<.001). ROC curve analysis demonstrated acceptable discriminative ability (AUC=0.738), with 82.5% sensitivity and 65% specificity for predicting ACL rupture based on fossa shape.

Conclusion: The morphology of the intercondylar fossa, particularly Type A configuration, is significantly associated with increased ACL rupture risk. These findings underscore the potential utility of morphological MRI assessments in screening high-risk individuals and guiding preventative strategies.