[Current developments in ultrasonography of the meniscus]

Sonography of the meniscus is a new diagnostic method, the instructive value and clinical relevance of which are subject to controversy. Sonographic assessment of the meniscus requires the use of focusing that can cope with the different anatomical conditions of the individual parts of the meniscus and can largely eliminate artifacts by means of wide sound-wave propagation. The dynamic examination technique allows the identification of both longitudinal and flap tears, which are relatively easy to diagnose, and of tear formations that are harder to visualize, such as horizontal and transversal tears. A sonographic criterion of a tear is the detection of a clearly visible, strong-signal double or single-stroke reflection pattern that can be traced in several section planes. While sonographic examination allows location of the tear, definite conclusions as to the shape of the tear are not possible on the basis of the echo pattern. In the literature, the statistical results, depending on the patient group and technical equipment, vary between 76% and 100% for sensitivity and between 50% and 97% for specificity, 74% and 93% for accuracy and between 61% and 95% for the positive prediction value. Sonographic examination of the meniscus is an easily available, noninvasive imaging technique that, as a supplement to clinical findings, can be used to optimize preoperative diagnosis and to check the indication for arthroscopy. Careful consideration of the technical requirements and systematic performance of the dynamic examination should lead to further improvement in the examination results and to growing clinical significance in the future.