Imaging Diagnosis of Injury to the Anterolateral Ligament in Patients With Anterior Cruciate Ligaments: Association of Anterolateral Ligament Injury With Other Types of Knee Pathology and Grade of Pivot-Shift Examination: A Systematic Review

Purpose: The purpose of this study is to systematically review the literature to evaluate the reliability, or the ability of a repeated measurement to yield consistent results, and validity of ultrasound (US) and magnetic resonance imaging (MRI) at evaluating anatomy and pathology of the anterolateral ligament of the knee (ALL) in the setting of anterior cruciate ligament (ACL) injuries. Furthermore, the incidence and association of ALL injury with the pivot-shift examination, and other structural injuries, will be reviewed for additional clinical relevance. Methods: Adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 2 reviewers independently searched the Medline, Embase, Cochrane, EBSCOhost, OVID, and Web of Science databases for all studies related to imaging of the ALL. All eligible articles and their references were screened by both reviewers. Studies discussing diagnostic imaging of the ALL with regard to identification of injury to the structure in patients with suspected ACL injury were included. No restrictions regarding date of publication, type of publication, or language in the included article were applied. The exclusion criteria included commentaries, case reports, and studies that did not attempt to identify the ALL as a discrete structure. Quality assessment and data extraction was performed for each included study before final analysis was performed. Results: A total of 13 articles were included for final analysis. In the included studies, at least 1 portion of the ALL could be visualized on MRI in 76% to 100% of knees, and injury to the ALL was identified in 10.8% to 62.5% of patients. Inter-and intraobserver reliabilities ranged from moderate to almost perfect. There was a consensus among studies that ALL injuries were significantly associated with injuries to the lateral collateral ligament, popliteus tendon, iliotibial band, and bony contusions to the lateral tibia and femur. Most of the included studies found a significant association of injuries to the ALL and a high-grade pivot-shift examination. Only 2 studies used US to evaluate for injury to the ALL, and both studies had almost perfect interobserver reliability. Only 1 study confirmed initial diagnoses at the time of the ACL reconstruction surgery. Conclusions: In patients with ACL injuries, concomitant ALL injuries can be identified on MRI or US with high levels of inter-and intraobserver reliability, and are often associated with a high-grade pivot-shift examination, lateral collateral ligament injury, and lateral femoral condyle and tibial plateau bone bruises.