[To visualize the posterolateral segment of the external meniscus. Value of the position of internal flexion rotation]

Interpretation of images of the posterolateral segment of external meniscus, during arthrography with contrasts of knee, is known to be difficult and this explains the possibility of false positives and the frequency of false negatives observed during exploration on this meniscus. A flexion-internal rotation projection of knee was used to improve the image of the posterior horn of the external meniscus, and analysis of results of about 100 examinations showed significant benefits. Use of the method is illustrated in a normal knee, and one with a rupture of posterior horn of external meniscus masked in extension and detected only in the flexion-internal rotation projection.