71-year-old male with left knee pain, not improving with physical therapy. Evaluate for lateral meniscal tear. MENISCI: Horizontally oriented high signal within the anterior horn of the lateral meniscus extending into the body and contacting the femoral articular surface on multiple sequences is consistent with a meniscal tear. There is also blunting of the free edge of the posterior horn of the lateral meniscus indicating a radial tear. There is a collection of intermediate and high signal intensity lateral to the body of the lateral meniscus likely representing a parameniscal cyst and perhaps synovitis. The medial meniscus is intact.ARTICULAR CARTILAGE AND BONE: There is a full-thickness articular cartilage defect along the lateral tibial plateau underlying the posterior horn of the lateral meniscus measuring approximately 1 cm in greatest diameter. There is also a full-thickness cleft along the cartilage of the lateral femoral condyle just above the torn free edge of the lateral meniscus with underlying degenerative subchondral signal intensity. Additional thinning of the cartilage of the lateral compartment is also present. There is superficial fraying of the cartilage of the weightbearing portion of the medial femoral condyle. There is focal intermediate signal intensity extending through the medial patellar facet, likely representing focal full thickness degeneration, with an underlying subchondral cyst. Subchondral cysts are also present within the inferior central aspect of the femoral trochlea with partial-thickness degeneration of overlying cartilage, and smaller subchondral cysts are seen more superiorly in the femoral trochlea and near the superior margin of the articular cartilage.LIGAMENTS: There are intrasubstance ganglia within the proximal anterior cruciate ligament but otherwise the ligament fibers appear intact. There is an elongated thin fluid collection tracking superficial to the lateral collateral ligament proper, which may arise from the underlying parameniscal cyst, however the ligament itself appears intact. The posterior cruciate ligament and medial collateral ligaments appear intact. EXTENSOR MECHANISM: The extensor mechanism appears intact.ADDITIONAL
1. Lateral meniscal tears as described above with findings suggestive of adjacent parameniscal cysts and edema/inflammation in the lateral soft tissues. The lateral ligamentous structures however appear intact.2. Cartilage defects and degeneration as described above.3. Intrasubstance ganglia within the anterior cruciate ligament.