15-year-old male with knee pain and swelling and joint pain for 3 months after fall, injury in basketball. Evaluate for medial meniscal tear. MENISCI: There is a complex tear of the anterior horn of the lateral meniscus with a horizontal and vertical component. There is an adjacent parameniscal cyst anteriorly measuring 6 mm (series 401, image 26). Horizontally oriented intermediate signal intensity within the posterior horn of the lateral meniscus which does not extend to the articular surfaces. Similar horizontally oriented intermediate signal intensity pattern is present within the posterior horn of the medial meniscus although to a lesser extent. The anterior horn of the medial meniscus is normal.ARTICULAR CARTILAGE AND BONE: Irregularity of the articular cartilage of the lateral femoral condyle and lateral tibial plateau with intermediate signal intensity clefts visualized, however no full-thickness defects are evident. The articular cartilage elsewhere about the knee is normal. There is bone marrow edema within the lateral tibial plateau and lateral femoral condyle. Bone marrow signal intensity elsewhere is normal.LIGAMENTS: There is high T2 signal intensity along the course of the ligament fibers of the anterior cruciate ligament distally near its insertion on the tibial plateau. The posterior cruciate ligament is normal. There is mild thickening of the lateral collateral ligament. The medial collateral ligament is normal.EXTENSOR MECHANISM: The extensor mechanism is intact and normal.ADDITIONAL
1. Complex tear of the anterior horn of the lateral meniscus with adjacent parameniscal cyst. Likely degeneration of the posterior horn of the lateral and medial menisci, more prominent within the lateral meniscus. 2. Nonspecific signal changes within the distal anterior cruciate ligament which may represent partial tear.3. Articular cartilage defect/degeneration within the lateral femoral condyle and lateral tibial plateau with associated subchondral bone marrow edema.4. Moderate knee joint effusion.