Mechanisms of anterior cruciate ligament injury

The anterior cruciate ligament (ACL) may be injured by various mechanisms. Each mechanism is know to produce specific combinations of ligamentous and meniscal abnormalities. This paper reports that this project was undertaken to evaluate the ability of MR imaging to characterize fully these different patterns of ACL injury. Two hundred fifty knee MR examinations in patients with suspected ACL injury were reviewed retrospectively. The presence of ACL injury and associated ligamentous, capsular, meniscal, and bone marrow abnormalities were correlated with the clinical history and mechanism of injury. Surgical or arthroscopic follow-up was available in all patients. As expected, ACL injuries were found to have a broad spectrum of associated abnormalities identified by MR imaging. Several mechanism-specific patterns of ligamentous and meniscal injury were observed; however, patterns of bone marrow edema and injury proved to be the most useful in predicting the mechanism of injury