Displaced Double-Layered Lateral Meniscus That Mimicked the Bucket-Handle Tear: a Case Report

Among the various types of congenital meniscal anomalies, the double-layered lateral meniscus is extremely rare. The double-layered meniscus consists of both the upper additional and the lower normal meniscus. As the upper additional meniscus is mobile, it can be easily displaced, while the lower lateral meniscus is usually normal in shape and volume. A 42-year-old woman suffering from pain and locking of her left knee underwent Magnetic resonance imaging (MRI) examination and an arthroscopic surgery. A rare meniscal abnormality was seen in her left knee, which presented as a double-layered lateral meniscus with displacement. It was remarkable that the upper additional meniscus was displaced over the intercondylar eminence of the tibia and it mimicked a bucket-handle tear. Even though it is rare, it is necessary to consider the possibility of displaced double-layered meniscus in the differential diagnosis of a bucket-handle tear. Here, we report the MRI and arthroscopic findings of a displaced double-layered lateral meniscus, which was similar to the bucket-handle tear.

Double-Layered Lateral Meniscus: A Case Report / 대한정형외과학회잡지

Many types of meniscal anomalies were reported. Authors found a double-layered lateral meniscus, with one meniscus overlying another. The 39-year old male patient had torn medial and lateral menisci. We performed partial medial and lateral meniscectomy, and incidentally found that lateral meniscus was double-layered. It was characteristic that the upper small accessory meniscus was firmly connected from the posterior horn to middle segments of the lower main meniscus along its peripheral edge. We left it alone. The symptoms were gone, So, it was thought that this anomaly was not related to the patient's symptoms.