Is the association of mediopatellar plica and discoid meniscus an irrelevant arthroscopic finding? Commentary about Kim et al article: "Medial and lateral discoid menisci: a case report." Angel Checa, Drexel University College of Medicine 18 January 2011 I read with interest the report by Kim et al (1): “Medial and lateral discoid menisci: a case report.” Although I agree with their annotations regarding discoid meniscus, I would like to make some comments. The mediopatellar plica is a well known cause of knee pain and mechanical complaints, and the reason why it was resected by the authors (1). However, the occurrence of medial plica and discoid meniscus is unknown, probably because it is underestimated by orthopedic surgeons, as occurred in this report (1). In a recent Spanish publication that included 220 consecutive arthroscopies of the knee in Cuban patients, the association of a pathologic mediopatellar plica in knees with lateral discoid meniscus represented 91 percent (2). Lateral discoid was present in 11 knees, ten of which had an associated medial plica. Whereby, the speculation of my colleagues and I was addressed toward a derangement during two important stages of the human knee development. An involvement of the differentiation at the interzone and the cavitation of the knee, may explain the association of the mediopatellar plica and discoid meniscus. Practical advice to our residents in training is to review the joint to look for medial plica in presence of discoid meniscus, overall in those cases with cartilage damage in the medial femoral condyle. The discoid meniscus is often easy recognizable arthroscopically, even by inexperienced operators. Otherwise, the diagnosis of a pathologic medial plica can be challenging in particular circumstances. Ultimately, discoid meniscus and other related abnormalities reported currently (3) were uncommon findings before the generalized use of arthroscopy. In my opinion, the association of mediopatellar plica and discoid meniscus requires additional studies; it is probably more frequent than reported. References 1. Kim S J, Lubis A M T. Medial and lateral discoid menisci: a case report. Sports Med Arthrosc Rehabil Ther Technol 2010; 2: 21 doi:10.1186/1758-2255-2-21 2. Checa A G, Damil R C, Tome O L. Frecuente association entre el menisco discoid lateral y la plica mediopatelar. ¿Una conexión patogénica? Med Desportiva 2002; 20: 95- 1-1. 3. Kim S J, Lee Y T, Kim D W. intrarticular anatomic variants associated with discoid meniscus in Koreans. Clin Orthop 1998; 356: 202-207. Competing interests Author declares no conflict of interest.