[Muscle and tendon injuries of the knee joint]

Muscles and tendons contribute greatly to stabilization of the knee joint and are crucial elements for normal joint function. Therefore, injuries of those structures cause variable degrees of disability, depending on the severity of the lesion. Due to the characteristic structural changes and alterations of signal intensities, MR imaging allows accurate identification and staging of acute injuries of muscles and tendons, as well as assessment of chronic or degenerative disease. The knowledge of anatomy and normal function of muscles and tendons, together with a thorough understanding of the mechanism and usual combinations of their injuries (e.g., posterolateral structures) allows an exact evaluation of injury-induced functional impairments to the knee joint. A detailed and exact radiological report is of the greatest importance for the referring clinician and the patient to determine optimal therapeutic strategies.