[Echography of the shoulder with the patient supine in the diagnosis of rotator cuff rupture].

We report a new method for shoulder sonography (US): the patient lies supine and his/her arm is positioned so as to optimize tendon depiction. The supraspinatus tendon, which is the most frequently involved structure in rotator cuff tears, is studied with the patient's arm dropped, elbow extended and forearm prone. Our series consisted of 49 surgical patients (arthroscopy in 16 and open surgery in 33 patients): US sensitivity in tear depiction was 84.8%, specificity 100% and accuracy 89.8%. Medium-small tears appeared as transonic areas within tendon substance and/or tendon focal thinning. Large tears appeared as: (a) missed or markedly thinned rotator cuff, with deltoid muscle approximation to the humeral head surface, (b) plenty of fluid collected around bulky tear margins. The US images of 36 patients were then reviewed and the details discussed. A new sign was observed in medium-small tears, that is a sharp hyperechoic band encircling the humeral cartilage (the compass sign). In conclusion, we believe that US performed with the patient in supine recumbency is easier to perform and provides a bigger field of view of the supraspinatus tendon; it also permits to keep stretched rotator cuff, with consequent image quality improvement.