Meniscal injures are commonly associated with anterior cruciate ligament (ACL) tears. A ramp lesion is an injury of the posterior horn medial meniscus and posterior medial capsule.
Educational Goals / Teaching Points
After viewing this exhibit the learner will be familiar with anatomy of the posterior horn medial meniscus and its capsular attachment. The viewer will understand the common appearance of ramp lesions. The classification of these ramp lesions will be discussed.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
At the posteromedial knee the joint capsule is firmly adherent to the medial meniscus. The capsule posteromedially is composed of meniscocapsular and meniscotibial attachments. As a result of the firm attachment the capsular attachment and the posterior horn medial meniscus stabilize the knee against anterior tibial translation and posteromedial rotation. Diagnosis and treatment of ramp lesions is critical to maintain biomechanical stability of the knee. Several meniscal ramp lesion classification systems have been proposed. These classification systems are based on involvement of the capsular structures, meniscal involvement and the degree of injury.
Meniscal ramp lesions are often subtle on magnetic resonance imaging. Since meniscal tears occur in up to 79% of patients with ACL rupture the posteromedial capsular junction with the medial meniscus should be scrutinized for injury. Failure to diagnose and treat a ramp lesion can predispose the patient to biomechanical instability.