Relation of discoid lateral meniscus and cord-like anterior intermeniscal ligament: morphological and clinical study

Discoid lateral meniscus is a rare disorder and its association with other variations in the knee joint has been reported. The anterior intermeniscal ligament has also been described as connecting the anterior convex margin of the lateral meniscus to the anterior horn of the medial meniscus. In the normal population, it was observed at 53-94%. Although the functional properties of the anterior intermeniscal ligament are not yet clarified, two distinct types of the ligament have been described according to their morphological characteristics as cord-like and membranous types. The purpose of this study was to evaluate any possible association between morphologic types of anterior intermeniscal ligament and discoid lateral meniscus. A retrospective study was designed; 20 discoid lateral menisci were operated using routine arthroscopic examination. Upon arthroscopic examination the thickness of the ligament and associated morphological changes were recorded systematically. The cord-like anterior intermeniscal ligament was an associated structure in 15 of the 20 knees with discoid lateral meniscus (75%). Patients with discoid lateral meniscus apparently have cord-like type anterior intermeniscal ligament, thus we conclude that cord-like type of anterior intermeniscal ligament is a frequent accompanying structure to discoid lateral meniscus and may have a potential stabilizing effect on its anterior stability.