19 year-old male with history of persistent left ankle pain and swelling, prednisone, concern for avascular necrosis. TENDONS: The Achilles' tendon appears normal. The medial, peroneal, and anterior tendons appear normal as well. LIGAMENTS: The lateral collateral ligament complex is intact. The visualized components of the deltoid ligament appear intact.ARTICULAR SURFACES AND BONE: There is serpentine signal abnormality within the distal tibial metaphysis, extending into the distal tibial epiphysis, with surrounding marrow edema, compatible with osteonecrosis. No subchondral fracture or articular surface collapse is identified. An additional small focus of osteonecrosis is present within the posterolateral aspect of the talar dome, without associated edema or articular surface collapse. There is a tibiotalar joint effusion, which appears to extend into the flexor hallucis longus tendon sheath. Mild edema along the periosteum of the distal tibia and the adjacent soft tissues is noted. ADDITIONAL
1.Osteonecrosis of the distal tibia with edema, a joint effusion, and adjacent soft tissue swelling.2.Small focus of osteonecrosis in the talar dome, without associated edema.3.Other findings as described above.