FREQUENCY OF ANTERIOR CRUCIATE LIGAMENT INJURY ON MAGNETIC RESONANCE IMAGING AND ITS ASSOCIATION WITH KNEE MORPHOMETRICS

Abstract

Background: Anterior cruciate ligament (ACL) injuries are common, especially in young, physically active individuals, and often result in long-term functional impairment. Objective: To determine the frequency of ACL injuries identified on MRI and to assess their association with morphometric parameters of the knee, including intercondylar notch width, posterior tibial slope, and ACL thickness. Methods: This cross-sectional analytical study was conducted at Najran University KSA from 1 Jan 2025 to 30 march 2025. A total of 93 patients were included in the study using non-probability consecutive sampling. All MRI examinations were performed using a 1.5 Tesla scanner employing standard knee imaging protocols. Imaging sequences included T1-weighted, T2-weighted, proton density (PD), and short tau inversion recovery (STIR) sequences in axial, sagittal, and coronal planes. ACL integrity was evaluated based on fiber continuity, signal intensity, and orientation, and categorized as intact, partially torn, or completely torn.  Results: ACL injuries were found in 47 out of 93 patients (50.5%), with complete tears observed in 68.1% of those cases. Patients with ACL injury had significantly narrower intercondylar notch widths (13.2 ± 1.6 mm vs. 15.1 ± 1.4 mm, p < 0.001), steeper posterior tibial slopes (13.9° ± 2.3° vs. 10.8° ± 2.0°, p < 0.001), and thinner ACLs (3.4 ± 0.6 mm vs. 4.8 ± 0.7 mm, p < 0.001) compared to those without injury. Although a higher proportion of females had ACL injuries, this was not statistically significant (p = 0.19).  Conclusion: It is concluded that ACL injuries are significantly associated with specific knee morphometric parameters. MRI-based assessment of intercondylar notch width, posterior tibial slope, and ACL thickness may help identify individuals at increased risk.