Reason: Evaluate posterior knee schwannoma History: Left knee pain and mass MENISCI: There is blunting and deformity of the posterior horn of the medial meniscus indicating complex degenerative tearing extending to involve the body of the meniscus. There is also linear signal abnormality within the anterior horn of the medial meniscus which extends to the femoral articular surface indicating a horizontal tear. There is minimal increased signal abnormality within the anterior and posterior horns of the lateral meniscus indicating intrasubstance degeneration. The lateral meniscus appears intact.ARTICULAR CARTILAGE AND BONE: There is severe articular cartilage degeneration affecting the patellofemoral articulation with large areas of the medial and lateral facet of the patella and femoral trochlea completely devoid of articular cartilage. There are tricompartmental osteophytes. There is full-thickness articular cartilage degeneration along the weightbearing surface of the medial femoral condyle with areas completely devoid of articular cartilage above the posterior horn of the meniscus. There is underlying subchondral signal abnormality. There is full-thickness articular cartilage degeneration along the anterior aspect of the lateral femoral condyle with areas completely devoid of articular cartilage with underlying subchondral signal abnormality.LIGAMENTS: There is increased signal abnormality and irregularity of the mid substance fibers of the PCL indicating a tear, unchanged. This may be chronic in etiology. The ACL appears intact. The LCL and MCL appear intact.EXTENSOR MECHANISM: The extensor mechanism appears intact.ADDITIONAL
1. Nonspecific 4 cm mass which courses along the bifurcation of the tibial and peroneal nerves, posterior to the knee, with nodular and septal enhancement on postcontrast sequences. While this may represent a peripheral nerve sheath tumor, a malignant peripheral nerve sheath tumor cannot be completely excluded by this examination.2. Osteoarthritis of the knee most pronounced along the patellofemoral articulation.3. Disruption of the PCL which may be chronic in etiology.4. Small joint effusion with findings suggestive of a synovitis as well as multiple loose bodies within the joint. 5. Tearing of the medial meniscus as described above. Other findings as described above.