13-year-old male with right knee pain and medial femoral articular surface lesion identified on radiograph presents for further characterization of this finding. MENISCI: The anterior and posterior horns of both menisci are intact and show normal signal intensity.ARTICULAR CARTILAGE AND BONE: An oval region of signal abnormality in the subchondral surface of the lateral aspect of the medial femoral epiphysis shows decreased signal intensity on T1-weighted images with mild surrounding marrow edema seen on T2-weighted images, consistent with an osteochondral defect. Mild cystic changes along the medial border of this defect suggests a chronic nature. Otherwise, bone marrow signal intensity is within normal limits. The articular cartilage of the femur, tibia, fibula and patella is intact.LIGAMENTS: The anterior ligament, posterior cruciate ligament, medial collateral ligament, lateral collateral ligament are intact.EXTENSOR MECHANISM: The quadriceps tendon and patellar tendon are intact.ADDITIONAL
Chronic-appearing osteochondral defect of the right medial femoral metaphysis.