21-year-old female with medial swelling, tenderness to palpation, inability to fully extend after trauma. Evaluate for MCL or meniscal injury. MENISCI: The medial and lateral meniscus are grossly normal.ARTICULAR CARTILAGE AND BONE: There is a small joint effusion extending to the suprapatellar recess. The articular cartilage appears normal. There is high T2 signal within the posterior femoral condyles and tibia and fibula, lateral greater than medial, most compatible with contusions. There is a depression along the lateral femoral condyle anteriorly compatible with a lateral femoral notch sign.LIGAMENTS: The proximal anterior cruciate ligament is not visualized and replaced with intermediate signal intensity on T2 compatible with an anterior cruciate ligament tear. The posterior cruciate ligament is intact. There is mild edema adjacent to the medial collateral ligament, which otherwise the ligament is grossly normal. The lateral collateral ligament is grossly normal.EXTENSOR MECHANISM: The extensor mechanism is intact.ADDITIONAL
1. Findings compatible with an anterior cruciate ligament tear.2. Findings most compatible with contusions along the posterior distal femur and proximal tibia and fibula, more prominent laterally.