Medial meniscus extrusion is a risk factor for knee pain in elderlies who didn't need clinical care on their knee - the bunkyo healthy study. Issue 1 (April 2020) - Huang, H.; Ishijima, M.; Kaneko, H.; Liu, L.; Aoki, T.; Negishi, Y.; Momoeda, M.; Nagao, M.; Tamura, Y.; Kawamori, R.; Kaneko, K.