Diagnostic Musculoskeletal Ultrasound in the Evaluation of the Knee Lateral Collateral Ligament

The lateral collateral ligament in the knee provides static restraint against varus-directed stress. Lateral collateral ligament injuries are much less common than those of the anterior cruciate or medial collateral ligament. When they do occur, they are more often associated with posterolateral corner injuries or meniscal injuries. A high index of suspicion is required when examining for lateral knee ligaments. An accurate diagnosis of partial tears or ruptures of the lateral collateral ligament is essential for appropriate treatment planning and optimizing patient outcomes. Diagnostic musculoskeletal ultrasound (MSKUS) offers a portable, real-time, and cost-effective alternative that is gaining traction in rehabilitation and sports medicine settings. MSKUS has emerged as a valuable, non-invasive imaging modality for evaluating ligament injuries, including sprains, partial tears, and ruptures. MSKUS is excellent at detecting changes in ligament composition and continuity. This article will review the utility of MSKUS in evaluating lateral collateral ligament injuries, including anatomy, common injury mechanisms, sonographic techniques, and clinical implications for rehabilitation professionals. Diagnosis of acute ligament injury by physical examination is often challenging and is frequently misdiagnosed. By integrating MSKUS into clinical practice, providers can improve diagnostic accuracy, enhance diagnostic confidence, monitor healing progression, and guide rehabilitation strategies to achieve optimal patient outcomes for patients with knee ligament injuries.