Tendinous insertion of semimembranosus muscle into the lateral meniscus

• Published in: Surgical and radiologic anatomy (English ed.) 1998-03, Vol.19 (6), p.365-369
• Main Authors: Kim, Y. C., Yoo, W. K., Chung, I. H., Seo, J. S., Tanaka, S.
• Format: Article
• Language: English
• ISSN: 0930-1038; 1279-8517
• DOI: 10.1007/s00276-997-0365-3

Forty-two cadaver knees were used for morphologic and MRI observations of the tendinous distal expansions of the semimembranosus m. and the posterior capsular structures of the knee. A tendinous branch of the semimembranosus m. inserting into the posterior horn of the lateral meniscus was found in 43.2% of the knees dissected, besides five already known insertional branches; capsular, direct, anterior and inferior, as well as the oblique popliteal ligament. The tendon had three morphologic types; thin, broad and round. All three types moved the lateral meniscus posteriorly when pulled on. Thus, the semimembranosus m. may also have a protective function for the lateral meniscus as well as the already well established function of protecting the medial meniscus in knee flexion. When a semimembranosus tendon attachment to the posterior horn of the lateral meniscus is present, its normal insertion is difficult to differentiate from a lateral meniscus tear in MRI and this may cause misdiagnosis.