Unilateral meniscomeniscal ligament.

Four normal variants of meniscomeniscal ligaments have been previously reported in the anatomy, arthroscopy, and radiology literature. The anterior and posterior transverse meniscal ligaments are the 2 most commonly observed, with a reported frequency of 58% and 1% to 4%, respectively. The last 2 variants include the medial and lateral oblique meniscomeniscal ligaments and account for a combined frequency of 1% to 4%.This article describes 2 patients with unilateral meniscomeniscal ligaments observed on magnetic resonance imaging. One patient had a unilateral lateral meniscomeniscal ligament extending from the anterior horn of the lateral meniscus to the posterior horn of the lateral meniscus and underwent conservative management. The second patient had a unilateral medial meniscomeniscal ligament with a concomitant medial meniscus tear and underwent arthroscopic intervention. The ligament was stable intraoperatively and, therefore, was not resected. Both patients had resolution of their symptoms.These 2 variants are additions to the previously described 4 normal intermeniscal ligament variants. The functions of the 2 new variants described in this article are poorly understood but are thought to involve meniscal stability. Accurate descriptions of normal variants can lead to the proper management of anomalous rare structures and prevent false imaging interpretations because these structures can closely mimic a double posterior cruciate ligament sign. Furthermore, an understanding of the various normal variants of intermeniscal ligaments can prevent unnecessary surgery that could result in further iatrogenic meniscus injury.