Anterolateral Ligament Tear in Acute Anterior Cruciate Ligament Rupture: Diagnostic Accuracy of MRI

Abstract
Background: The anterolateral ligament is a special ligamentous structure traversing the knee joint along its anterolateral part, originating from the lateral femoral epi-condyle, with an oblique course through the joint capsule to be inserted at the anterolateral tibial surface just posterior to Gerdy's tubercle. Evaluation of anterolateral ligament has been done by MRI. The rate of its visualization is by MRI is varying from 50 to 100%. There is a significant increase in the incidence of association between the anterolateral ligament and ACL lesions as detected by MRI.
Aim of Study: The present study was aimed to give a comprehensive evaluatation for the ability of MRI to diagnose anterolateral ligaments injuries in patients with acute tears of the anterior cruciate ligaments.
Material and Methods: A retrospective study on ninety six patients underwent ACL reconstruction was done. The MRI knee studies of those patients were done within two months after the initial injury and the anterolateral ligament pattern was evaluated; either non-detectable, normal or path-ological. Two expert musculoskeletal radiologists evaluated the images.
Results: The present study revealed that 20 (21%) cases of the 96 ACL injured cases, Anterolateral Ligament (ALL) could not be detected (21 %), while 76 (79%) could be detected with MRIs. Twenty cases of the visualized ALLs were seen intact (26%), on the other hand, 56 knees (74%) showed imaging abnormalities. The site of injury of the ALL was involving mainly the distal segment (tibial part) in 34 cases (61%), the proximal segment (femoral part) was less common in 14 cases (25%) and both parts were injured in 8 cases (14%).
Conclusion: Anterolateral Ligament (ALL) are commonly associated with acutely ruptured Anterior Cruciate Ligament (ACL). Therefore, MRI findings together with clinical corre-lations are still essential factors in the surgical decision reconstruction of ALL avoiding unsatisfactory results post ACL reconstruction alone.