50-year-old female with right knee cyst versus mass seen on plain film. MENISCI: The lateral meniscus appears intact. There is intrasubstance degeneration of the posterior horn of the medial meniscus. There is a full-thickness radial tear of the posterior horn of the medial meniscus, near its root (image 12; series 10). There is degenerative tearing of the posterior horn and body of the medial meniscus. The anterior horn appears intact.ARTICULAR CARTILAGE AND BONE: There is full-thickness articular cartilage degeneration along the lateral compartment with underlying degenerative subchondral signal abnormality. There is relative sparing of the lateral compartment articular cartilage. There is full-thickness articular cartilage degeneration affecting the patellofemoral joint with large areas of the lateral facet of patella and femoral trochlea completely devoid of articular cartilage with underlying subchondral cyst formation. There are also areas completely devoid of articular cartilage along the medial facet of the patella. There are tricompartmental osteophytes.LIGAMENTS: There is thickening of the anterior cruciate ligament suggestive of prior injury or sprain. The PCL appears intact the MCL appears intact. The LCL appears intact. EXTENSOR MECHANISM: The extensor mechanism appears intact. Note is made of patella alta. The Insall Salvati ratio measures 1.6, which can be seen in patient's with patellofemoral instability.ADDITIONAL
1. Moderate joint effusion extending posteromedially into a Baker's cyst with findings indicating a synovitis. 2.2 cm lobulated focus of fluid signal intensity along the medial femoral condyle corresponding to the findings seen on recent radiographs, likely represents a lobulated component of the aforementioned Baker's cyst.2. Severe osteoarthritis of the right knee most pronounced along the patellofemoral joint and other findings as described above.3. Radial tear of the posterior horn of the medial meniscus with additional complex degenerative tearing as described above.