Evaluation of the anterolateral ligament of the knee by magnetic resonance imaging in patients with chronic anterior cruciate ligament rupture

Abstract Objective The purpose of this study was to evaluate the visibility of the anterolateral ligament (ALL) by magnetic resonance imaging (MRI) in patients with chronic anterior cruciate ligament (ACL) rupture. Materials and methods This retrospective case – control study compared 1.5 - T MRI scans for 50 patients with a chronic ACL rupture with those of a control group of 50 patients with an intact ACL. The ALL was evaluated in three portions: femoral, meniscal, and tibial. The status of each portion was classified as visualized or non-visualized. Two radiologists separately reviewed all the MRI scans to evaluate interobserver reliability. Results At least one portion of the ALL was visualized in 100% of the control group and 72% of the chronic ACL rupture group. All three portions of the ALL were identified in 72% of the control group but only 10% of the chronic ACL rupture group. In both groups, the most commonly visualized portion was the meniscal portion and the least visualized was the tibial portion. In 18% of the chronic ACL rupture group, no portion of the ALL was visualized. Conclusions The visibility of the ALL of the knee was significantly lower in patients with a chronic ACL rupture than in those with an intact one.