19-year-old male with a history of lupus and left lower extremity osteonecrosis presents with worsening pain. Evaluate for AVN of the right knee. MENISCI: The medial and lateral meniscus appear intact.ARTICULAR CARTILAGE AND BONE: Note is made of serpentine signal abnormality in the medial and lateral femoral condyles, most pronounced along the weightbearing surface of the lateral femoral condyle, consistent with avascular necrosis. There is extensive bone marrow edema type signal abnormality within the lateral femoral condyle.LIGAMENTS: The cruciate and collateral ligaments appear intact. EXTENSOR MECHANISM: The extensor mechanism appears intact.ADDITIONAL
Avascular necrosis of the distal right femur.