Double-layered lateral meniscus: a newly found anomaly.

We report two cases of a double lateral meniscus, with one meniscus overlying another. It was characteristic that the upper accessory meniscus was connected at the posterior horn and middle segments of the lower meniscus. Symptoms in both cases disappeared after resecting the upper meniscus arthroscopically. There was no evidence of tear or other pathologic finding in the meniscus, which showed no disturbance of the fiber arrangement.