56-year-old female presents with right knee pain, swelling, and a "knee pop"; evaluate for ligament tear. MENISCI: There is full-thickness avulsion of the posterior horn of the medial meniscus from its root associated with mild medial extrusion of the body of the medial meniscus. Intrasubstance increased signal within the posterior horn and body of the medial meniscus suggests mucoid degeneration. Within the body of the medial meniscus, this signal extends to the tibial articular surface perhaps representing degenerative fraying/tearing. The lateral meniscus appears normal for age.ARTICULAR CARTILAGE AND BONE: There is moderate degeneration of the articular cartilage of the patellofemoral joint, particularly along the lateral facet of the patella. There is perhaps a small focus of partial thickness degeneration of the articular cartilage along the weightbearing surface of the medial femoral condyle. The articular cartilage of the lateral compartment appears intact.LIGAMENTS: The cruciate and lateral ligaments are intact.EXTENSOR MECHANISM: The extensor mechanism is intact.ADDITIONAL
1. Avulsion of the root of the posterior horn of the medial meniscus.2. Moderate-sized joint effusion and a Baker's cyst with edema along the medial head of the gastrocnemius which may reflect leakage or rupture of the Baker's cyst.3. Cartilage degeneration, most pronounced at the patellofemoral joint.