Purpose. To assess anterolateral complex (ALC) injuries in patients with acute anterior cruciate ligament (ACL) rupture on magnetic resonance imaging (MRI).
Methods.Patients with acute ACL rupture who underwent ACL surgery between 2015 and 2017 and had an MRI within 6 weeks of the initial trauma were included. Two radiologists assessed MR images retrospectively for the status of the ALC, including the iliotibial band (ITB), Kaplan fibers, and anterolateral ligament (ALL), as follows: Grade 0: normal, Grade 1: periligamentous edema, Grade 2: partial, and Grade 3: complete tear. The findings were analysed using a Friedman test and weighted-kappa (κ) values .Results. Sixty-nine MRI scans were reviewed. Fifty-one % of 69 patients had associated injury of the ITB (Grade 1, n=31; Grade 2, n=4), 33% had associated injury of the Kaplan fibers (Grade 1, n=21; Grade 2, n=2), and 57% had associated injury of the ALL (Grade 1, n=12; Grade 2, n=22; Grade 3, n=5). There was a significant difference in the frequency and grading between ITB, Kaplan fiber and ALL injuries (P ≤ .032). Inter-reader agreement for assessing the ALC on MRI was almost perfect ( κ ≥ 0.922).
Conclusion.Based on MRI analysis, ALL injuries were found with varying degrees of severity and intensity with noted injuries to associated surrounding fibers in patients with acute ACL rupture.