60-year-old female with question of avascular necrosis of the right knee. MENISCI: The menisci appear intact without significant pathologic defect.ARTICULAR CARTILAGE AND BONE: There is severe generalized thinning of the articular surfaces of the patella, femur, and tibia. Further, there are full-thickness defects with underlying sclerosis/subchondral cysts visualized in the medial tibial plateau, medial femoral condyle, and femoral trochlea.LIGAMENTS: There is thickening and mild edema within the anterior cruciate ligament, however the fibers appear intact. This likely is representative of ligamentous strain. The PCL appears intact. The MCL and LCL complex appears intact.EXTENSOR MECHANISM: The extensor mechanism appears intact.ADDITIONAL
1. Severe osteoarthritis affects the right knee.2. Findings compatible with ACL strain, but no complete tear.3. Geographic areas of signal abnormality likely representing avascular necrosis of the femoral articulation, similar to that seen on prior radiograph.