Meniscal root tears occur frequently in multi-ligament knee injury and can be predicted by associated MRI injury patterns

Purpose The frequency of meniscal root tears in association with multi-ligament knee injury has not been established but adds to the complexity of surgical reconstruction and may have long-term consequences. Therefore, identifying root tears, on preoperative imaging, is important. The aim of this study was to identify the frequency of meniscal root tears, on preoperative magnetic resonance imaging, following multi-ligament injury and distinguish associated injury patterns that may aid detection. Methods Cases were identified from a prospectively collected institutional database. The magnetic resonance imaging of 188 multi-ligament injuries [median age 31 years (range 16–64)] was retrospectively reviewed by three musculoskeletal radiologists with the presence of meniscal injuries recorded alongside the ligament injury pattern and intra-articular fractures. Assessment of injury pattern was solely made on this imaging. Results 38 meniscal root injuries were identified in 37 knees (overall frequency = 20.2%; medial = 10.6%; lateral = 9.6%). The frequency of meniscal root tears was not increased in higher grade injuries (21.5% vs. 17.0%, n.s.). Valgus injury patterns were associated with lateral root tears ( p