Recurrent patellar dislocation MENISCI: There is a lobulated collection of fluid signal intensity which appears to arise from the peripheral fibers of the posterior horn of the medial meniscus and extends along the posterior margin of the MCL. Based on the proximity to the posterior horn, this could represent parameniscal cyst although we see no fluid-filled tear extending to either articular surface. Alternatively, it may represent a ganglion.The lateral meniscus is intact.ARTICULAR CARTILAGE AND BONE: No significant abnormality noted. The femoral trochlea appears shallow suggesting dysplasia. There is no abnormal marrow signal.LIGAMENTS: The cruciate and collateral ligaments are intact. Portions of the MPFL are not well visualized which may reflect chronic tearing. There is nonspecific edema within the soft tissues surrounding the medial retinaculum.EXTENSOR MECHANISM: No significant abnormality noted. There is no patella alta and the TT to TG distance is 9 mm, which is within normal limits.ADDITIONAL
1. Imaging findings of femoral trochlea dysplasia with poor definition of portions of the MPFL consistent with known history of recurrent patellar dislocation. The TT to TG distance is normal.2. Lobulated cystic structure along the distal femur and medial meniscus which could represent a parameniscal cyst although no discrete meniscal tear is identified. Alternatively, this may represent a ganglion.