Prevalence of anterolateral ligament injuries and lateral meniscus tear on MR imaging in patients with both-bundle tear vs. selective bundle incomplete tear of the anterior cruciate ligament

Objectives We investigated the prevalence of anterolateral ligament (ALL) injury and lateral meniscus (LM) tear in cases with both-bundle tear and selective bundle incomplete tear of the anterior cruciate ligament (ACL). Methods A total of 174 cases of magnetic resonance (MR) images that had an ACL tear and underwent arthroscopic ACL reconstruction were retrospectively reviewed. ACL injury was classified into both bundle, anteromedial bundle, and posterolateral bundle (PL) on arthroscopic finding. The ALL was divided into three portions: femoral, meniscal, and tibial. ALL injury was scored into three groups: grade 0 is intact; grade 1 is stranding and edema surrounds the expected location of the ALL; grade 2 is clear discontinuity of the ALL consistent with rupture. Traumatic LM tear was also assessed on MR images. Results The total prevalence of ALL injury was 36.2% (reader 1) and 42.0% (reader 2). ALL injury was statistically related to the selective bundle tear ( p = 0.002 and 0.004, readers 1 and 2). PL bundle tear was significantly correlated with the ALL injury ( p value