[Posteromedial corner of the knee].

The posteromedial corner of the knee is increasingly being recognized in orthopedic surgery, traumatology and musculoskeletal radiology. The medial collateral ligament consists of a superficial part and a deep part. The posteromedial corner consists of the posterior oblique ligament (POL), the oblique popliteal ligament (OPL), the semimembranosus tendon and its arms, the posteromedial joint capsule and the posterior horn of the medial meniscus. The structures provide stability to the knee joint with respect to valgus stress, rotational stability as well as with respect to anterior and posterior translation. Injuries are frequently associated with other severe injuries of the knee. This underlines the importance of recognizing the structures and their injuries on magnetic resonance imaging (MRI), in order to enable adequate therapy.