[The value of ultrasound in the diagnosis of capsule ligament injuries of the upper ankle joint].

Ankle ligament injuries are usually diagnosed by clinical and radiological examination. In this study we tried to determine the accuracy of dynamic sonography in the diagnosis of ankle ligament injuries. From 1 April 1987 to 1 July 1988, 72 patients with ligamentous injuries of the ankle were examined sonographically. The dynamic stability of the anterior talofibular ligament was determined by measuring the length of the ligaments under normal and stressed conditions. The anatomical course of the ligaments was used as the plane of section. Clinical and radiological examinations were used to determine whether an operation was indicated, and the results of these examinations were compared after the operation with the sonographic and intraoperative findings. Dynamic examination of the stability of the anterior talofibular ligament yielded findings compatible with the intraoperative findings in 64 of the 72 cases (88.8%). The mean difference in length between normal and stressed conditions was 7.4 mm, with a range of 6-12 mm in the case of rupture of the ligament. A high level of agreement between sonographic and intraoperative findings was also found for the calcaneofibular ligament. In 62 of the 72 cases (86.1%) a correct diagnosis was possible. The mean difference in length in this plane of section was 10.6 mm, with a range of 7-17 mm. The sensitivity and specificity of ultrasound in the diagnosis of rupture of the ligaments were between 80% and 90%, respectively, and the positive predictive value was about 95%. Sonography with a high-resolution scanner allows a correct diagnosis of ligamentous lesions at the ankle joint in 80-90% of cases.(ABSTRACT TRUNCATED AT 250 WORDS)