Female 13 years old History: h/o L knee twisting injury 2/28 with immediate knee pain and swelling; significant effusion and +lachman exam in clinic 3/8, c/f ACL tear MENISCI: The menisci are intact without tear or other significant abnormality.ARTICULAR CARTILAGE AND BONE: There are bone contusions of the lateral femoral condyle and medial patellar facet. There is fragmentation of the articular cartilage of the medial patellar facet (Series 501 image 13 and 14). The trochlear groove is mildly flat. No acute fracture is identified.LIGAMENTS: The ACL, PCL, MCL, and LCL complex are intact and normal in appearance. Partial tearing of the medial patellofemoral ligament with few strands appearing intact.EXTENSOR MECHANISM: No significant abnormality of the extensor mechanism.ADDITIONAL
1.Findings consistent with transient patellar dislocation with associated partial tearing of the medial patellofemoral ligament, medial patellar cartilage fragmentation and moderate joint effusion.2.Small Baker's cyst.