Bilateral discoid medial menisci: Incomplete type in one knee and complete type in opposite knee.

A discoid medial meniscus is a relatively rare pathology of the knee joint. And bilateral cases are even more rare. In the review of the literature by the authors, Only 13 cases of bilateral medial discoid menisci have been reported. We present one case of bilateral discoid medial menisci. One knee had an incomplete type verified by both magnetic resonance imaging (MRI) and arthroscopy. The other knee showed a complete type of medial discoid meniscus in MRI. Therefore, we suggest that similar pathology in the contralateral knee should be suspected, even if the patient is asymptomatic, if a complete or incomplete discoid medial meniscus is identified.