[Ultrasound determination of the humerus retrotorsion angle. An experimental and clinical study].

We examined the value of ultrasound to determine the retroversion of the humerus in an experimental and clinical study. In twenty human upper arms of corpses the retroversion angle was measured by ultrasound and by direct means using a paralellograph. The angle was also evaluated by sonography and CAT scan in 7 patients, and in 6 patients by sonography and x-ray. There was a poor correlation between sonographic measurement and direct measurement, CAT scan, or x-ray. Hence, we do not recommend sonography as a useful tool in preoperative planning. For this purpose, CAT scan or x-ray should be preferred. However, sonography may be useful for screening.