Bilateral discoid medial menisci

This article adds 2 more cases of bilateral discoid medial menisci to the p reviously reported 9 cases. The radiographs of the first case revealed bila teral cupping of the medial tibial plateaus and a small lytic lesion of the left distal medial femoral metaphysis. Beside the posteriorly unstable inc omplete type discoid medial meniscus, the left knee had several associated arthroscopic findings: depression of the medial tibial plateau with exposed subchondral bone, anomalous insertion of the anterior horn of the discoid meniscus to the anterior cruciate ligament, a pathological medial plica, an d longitudinal deep fissures in the trochlea, The second case was a complet e type with peripheral horizontal cleavage tears. Following arthroscopic su rgery, magnetic resonance imaging (MRI) scans of the contralateral knees we re obtained in both cases to search for bilaterality. MRI revealed discoid medial menisci in the unoperated knees as well. The short-term results of a rthroscopic meniscectomy may not be as satisfactory as those reported for n ormal menisci.