title: Internal knee lesions and medial discoid meniscus.
abstract: The authors stress the great importance of stability in the normal functioning of the knee and its resistance to injury. They describe a case of multiple internal lesions involving the anterior cruciate ligament, the medial collateral ligament and the lateral meniscus sustained in a knee already affected by a discoid medial meniscus. These lesions were caused by a relatively slight injury and the knee for some time over reacted to the slightest stress. Operation revealed the existance of a discoid medial meniscus and in the view of the authors this was the cause both of the knee's instability and previous episodes as well as the final severe traumatic syndrome revealed at operation. Discoid medial meniscus is extremely rare. Smillie's classification into three groups and the various pathogenetic hypotheses are discussed. The authors analyse the relation between knee instability and meniscal malformation and conclude that discoid medial meniscus plays a primary role in rendering the joint highly vulnerable.
mesh_terms: D000293:Adolescent; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007718:Knee Injuries / Q000000981:diagnostic imaging / Q000601:surgery; D011859:Radiography; D013314:Stress, Mechanical; D000070600:Tibial Meniscus Injuries