[Ultrasound criteria of fresh rupture of the anterior cruciate ligament].

In a prospective, controlled, monocentric clinical study 193 recently traumatized knee joints, suspicious of a ruptured anterior cruciate ligament, were examined sonographically. Three indirect signs of rupture were analyzed and compared to the results of the clinical tests of stability (Lachmann). Arthroscopy and arthrotomy were regarded as approved methods of reference. The sonographic pattern of an echo-free mass in the area of the femoral insertion of the anterior cruciate ligament proved to be more informative (sensitivity 0.91, specificity 0.78, effectivity 0.84) than the clinical signs of instability. A standardized sonographic examination of the knee joint should be a constant component of the posttraumatic examination. It is an inexpensive method, easy to learn and to perform, and is more reliable in the diagnosis of the ruptured anterior cruciate ligament than the clinical evaluation of instability.