13 year-old male with effusion, popping, pain for one year, evaluate for internal derangement MENISCI: There displacement of the posterior horn and body of the lateral meniscus into the intercondylar notch, adjacent to the lateral fibers of the ACL. There is enlargement and increased signal intensity of the anterior horn of lateral meniscus, indicating extensive mucoid degeneration, with small degenerative type tears extending to the femoral articular surface. These findings suggest the possibility of a discoid meniscus with degenerative tearing and displacement as described above, although we cannot confirm discoid morphology on the base of this study.ARTICULAR CARTILAGE AND BONE: No focal articular cartilage defects. The bone marrow signal is within normal limits.LIGAMENTS: The ACL is intact although there may be some mucoid degeneration of the ligament extending from the anterior horn of the lateral meniscus. The PCL is intact. The medial and lateral collateral ligaments are intact.EXTENSOR MECHANISM: The quadriceps and patella tendons are intact.ADDITIONAL
Degeneration, tearing and displacement of the lateral meniscus as well as other findings as described above.