Magnetic resonance imaging of a symptomatic meniscal ossicle.

Meniscal ossicles are uncommon in humans. They are usually located in the posterior horn of the medial meniscus and are generally first observed on roentgenograms as intraarticular corticated bone densities. Many different entities appear similar to meniscal ossicles on roentgenography. Magnetic resonance imaging (MRI) can help to distinguish between these different entities and thereby assist in guiding treatment. Magnetic resonance imaging also can identify concurrent intraarticular pathology (e.g., meniscal tears), which may influence the choice of treatment. In a 29-year-old man, MRI confirmed the intrameniscal location of a corticated bone density seen in the posteromedial knee on roentgenograms. An associated medial meniscus tear was found at arthroscopy. The patient's symptoms were relieved after resection of the meniscal ossicle and the associated meniscal tear.