At this point in time the approach to the diagnosis of rotator cuff tendon tears is not consensual. The French surgeons, considering they have a good experience of this method, preferably use a shoulder CT-arthrography. Whereas in the United States surgeons rather rely on MRI or MR-arthrography of the shoulder. However, nobody can say which of these three examinations is most precise and gives the best information. We proposed to carry out the three examinations at the same time in a large number of patients who needed to be operated for a rotator cuff tendon tear and then to compare the results of each of these examinations with the operative observations.