High prevalence of anterolateral ligament abnormalities in magnetic resonance images of anterior cruciate ligament-injured knees.

The purpose of this study was to identify the newly described anterolateral ligament of the human knee on magnetic resonance imaging and to describe its eventual radiological abnormalities in anterior cruciate ligament-injured subjects. A retrospective cohort study on a series of consecutive subjects undergoing anterior cruciate ligament reconstructive surgery was performed. The MR images of 206 included knees were studied and the status of the anterolateral ligament status was judged to be either "non-visualized", "normal" or "abnormal". Of all the visualized anterolateral ligaments, 44 (21.3%) were considered uninjured, while 162 (78.8%) knees demonstrated radiological ALL abnormalities. The majority of ALL abnormalities were situated in the distal part of the ligament (77.8%). In conclusion, the anterolateral ligament can be identified on classic knee magnetic resonance images. Although anterior cruciate ligament injured subjects often demonstrated associated anterolateral ligament lesions, further research is needed in order to establish the clinical relevance of these highly frequent radiological abnormalities.