[The value of sonography in injuries of the knee joint]

In an experimental study we examined three knee specimens with regard to the value of ultrasound for imaging soft tissue structures. Subsequently we documented artificial lesions at the menisci and ligaments. With this experience we started a prospective study comparing the preoperative ultrasound investigation with the results of arthroscopy in 101 patients. For ultrasound evaluation we used a 5 MHz linear and a 7.5 MHz sector scanner. In the experimental as well as in the clinical study the menisci were well visualised. For medial meniscus lesions the accuracy and the predictive value was 81%. For the lateral meniscus the predictive value was 80%, although there was only an accuracy of 7% because of a large number of false positive results. We were not able to reliably detect cruciate ligament ruptures. However, ultrasound was useful to visualise Baker's cysts, bursitis, and jumper's knee.