The Importance of the Intercondylar Notch in Anterior Cruciate Ligament Tears

Background: The factors associated with anterior cruciate ligament (ACL) tears are not completely clear. Some studies have shown that patients with a narrow intercondylar notch have a predisposition for ACL tears. Purpose: To determine the relationship between the alpha angle and intercondylar notch width measurements and ACL tears. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 530 patients (308 with ACL rupture, 222 with healthy ACLs) were included in this study. The alpha angle and intercondylar width were measured from magnetic resonance images (MRIs). Binary logistic regression analysis was performed to determine the influence of the variables on ACL status (normal or torn). Odds ratios (ORs) and their respective 95% CIs were also calculated. Results: No significant differences in patient age and the affected knee were found between patients with normal or torn ACLs. The mean alpha angle was higher in patients with a torn ACL than in those with an intact one (57.5 degrees +/- 5.5 degrees vs 56.2 degrees +/- 4.5 degrees ; P=.009). Intercondylarwidth was significantly lower in patients with a torn ACL than in those with an intact one (18.2 +/- 3.1 vs 19.5 +/- 3.6mm; P <.001). A highly significant difference between men and women was found for mean intercondylar notch width (19.3 +/- 3.3 vs 17.4 +/- 3.1 mm; P <.001). In a logistic regressionmodel, sex, intercondylar width, and alpha angle were statistically significant when adjusted for age. Conclusion: Study results suggest that the ACL tears are associated with a narrow intercondylar notch and a high alpha angle, and that tears occur more frequently in men than in women. Clinical Relevance: The model proposed in this study could be used by the physician in the medical office as a tool to identify the risk factors that may predispose a patient for a potential ACL tear.