ABSTRACT
<p><b>OBJECTIVE</b>To explore clinical characteristics of 4 patients with knee discoid medial meniscus under arthroscopic.</p><p><b>METHODS</b>From April 2012 to May 2015, 4 patients(4 knees) with knee discoid medial meniscus were treated with arthroscopic, including 1 male and 3 females, aged from 7 to 56 years old with an average of 26 years old. All patients were performed discoid meniscus plasty under arthroscopic. Postoperative symptoms and signs were observed, and clinical effects were evaluated by Lysholm knee scores.</p><p><b>RESULTS</b>All patients were followed up from 6 to 20 months with an average of 12 months. At the latest follow-up, Lysholm scores were 83.5±10.0;2 knees got excellent results, 1 knee good, and 1 knee moderate.</p><p><b>CONCLUSIONS</b>Knee discoid medial meniscus is easily missed diagnosis for atypical and early clinical symptoms , and seeing a doctor for obvious symptoms with meniscus tear, and could receive good curative effects after diagnosis as soon as possible.</p>