55-year-old male with knee pain and previous subchondral plasty. New AVN? MENISCI: There is linear increased signal abnormality which traverses the posterior horn of the medial meniscus and extends to the tibial articular surface consistent with a horizontal tear which extends to the body of the meniscus. The anterior horn appears intact. The lateral meniscus appears intact.ARTICULAR CARTILAGE AND BONE: There is full-thickness articular cartilage degeneration along the weightbearing surface of the medial femoral condyle and medial tibial plateau with underlying degenerative subchondral signal abnormality and cyst formation. There is full-thickness articular cartilage degeneration along the weightbearing surface of the medial tibial plateau and thinning of the articular cartilage along the lateral femoral condyle. There is full-thickness articular cartilage degeneration along the lateral facet of the patella. There is partial-thickness articular cartilage degeneration along the medial facet of the patella. There is full-thickness articular cartilage degeneration along the lateral facet of the femoral trochlea and centrally. There is diffuse increased signal abnormality within the medial femoral condyle and to a lesser degree the medial tibial plateau which may represent avascular necrosis although no characteristic serpentine signal abnormality is identified.LIGAMENTS: The cruciate and collateral ligaments appear intact. EXTENSOR MECHANISM: The extensor mechanism appears intact.ADDITIONAL
1. Diffuse bone marrow signal abnormality within the medial femoral condyle and medial tibial plateau may represent avascular necrosis superimposed on degenerative osteoarthritic changes, although this does not demonstrate the typical serpentine signal abnormality characteristic of this entity.2. Osteoarthritis of the right knee including full-thickness articular cartilage degeneration as described above3. Horizontal tear of the medial meniscus as described above.