48-year-old male patient with history of two patellar dislocations in 2008 and 2011 as well as instability. Assess medial patellofemoral ligament, trochlear dysplasia, measure TT-TG. MENISCI: There is attenuation of the posterior horn and body of the medial meniscus, which could represent chronic attritional tearing or changes from partial meniscectomy. There is obliquely oriented linear signal in the peripheral fibers of the body and posterior horn of the medial meniscus that extends to the tibial articular surface. While this is compatible with a tear, this may represent intrasubstance degeneration that preceded a partial meniscectomy and now contacts the articular surface.The lateral meniscus is intact.ARTICULAR CARTILAGE AND BONE: There is a focal full-thickness articular cartilage defect along the medial patellar facet. There is also focal thinning along the anterior aspect of the lateral femoral condyle that is associated with osteophyte formation. No additional fluid-filled cartilage defects are seen.LIGAMENTS: The anterior cruciate ligament is slightly thickened, which may represent mucoid degeneration, however, we see no tear. The posterior cruciate ligament, medial collateral ligament, and lateral collateral ligament complex are intact. The medial patellofemoral ligament appears thin and its femoral attachment is not clearly defined, which may represent chronic injury; however, we see no edema adjacent to the medial retinaculum to suggest recent injury.EXTENSOR MECHANISM: The extensor mechanism is intact. The Insall-Salvati ratio is within normal limits.ADDITIONAL
1.Focal full-thickness articular cartilage defect of the medial facet of the patella.2.The medial patellofemoral ligament appears thinned and its femoral attachment is not clearly defined, which may represent chronic injury. However, we see no edema adjacent to the retinaculum to suggest recent injury nor do we see other specific features of patellofemoral instability.3.Abnormal signal within the meniscus as described above may represent tearing or prior meniscectomy changes.4.Mucoid degeneration of the anterior cruciate ligament.5.Edema along the posterolateral aspect of the distal femoral metaphysis is of uncertain etiology, but could represent a tear of an accessory plantaris muscle or lateral segmental anomalous origin of the gastrocnemius muscle. 