11-year-old male with left knee pain and swelling MENISCI: No significant abnormality noted.ARTICULAR CARTILAGE AND BONE: At the anterior aspect of the lateral femoral condyle, there is a focal loss of at least 2.2 cm articular cartilage. A small amount of fluid tracks beneath the remaining superior aspect of the articular cartilage. Bone marrow edema is noted deep to this region in the anterior aspect of the lateral femoral condyle.Articular cartilage of the patella appears intact.LIGAMENTS: The anterior cruciate ligament is intact. The posterior cruciate ligament is intact. The medial collateral ligament is intact. The lateral collateral ligament complex is intact. EXTENSOR MECHANISM: The extensor mechanism is intact.ADDITIONAL
1.Large focal defect of the articular cartilage along the anterior aspect of the lateral femoral condyle as described above. Loose body within the joint effusion likely represent articular cartilage from lateral femoral condyle. 2.Fluid interposed between the articular cartilage superior to the defect and the bone suggestive of laminar tearing. 3.Large joint effusion with likely layering of blood products. 