50-year-old female with knee pain and calcifications of the MCL. MENISCI: Intrasubstance signal within the lateral and medial posterior horns and body of the menisci suggests mucoid degeneration, but we see no meniscal tear.ARTICULAR CARTILAGE AND BONE: There is severe degeneration of the articular cartilage of the patella and much of the lateral facet is devoid of articular cartilage. There is also focal degeneration of the cartilage of the femoral trochlea inferiorly with underlying subchondral cysts. There are full-thickness and near full-thickness cartilage defects along the lateral femoral condyle anteriorly. Small additional subchondral cysts are noted anteriorly and posteriorly along the femur.LIGAMENTS: There is heterogeneous signal intensity adjacent to the superior fibers of the MCL consistent with edema and mineralization as seen on recent radiographs. There is signal abnormality within the fibers of the proximal ligament, suggestive of sprain/partial tear. The proximal fibers of the medial patellofemoral ligament are not well-visualized and may be torn.EXTENSOR MECHANISM: The quadriceps extensor mechanism appears intact. There is a small amount of edema within the superolateral aspect of Hoffa's fat pad.ADDITIONAL
1. There is a sprain/partial thickness tear of the proximal fibers of the MCL with associated periligamentous inflammation and heterotopic mineralization. The proximal fibers of the MPFL are not well visualized and we cannot exclude a tear.2. Osteoarthritis most severely affecting the patellofemoral joint.