This study was designed to assess the relationship between the morphologic appearance of the acromion and rotator cuff disease.

We retrospectively reviewed the MRI and radiographs of patients who were either in the rotator cuff disease group (56 cases) or a control group (25 cases). The average age of the patients was 46 years old (range, 14-86 yrs). We analyzed six parameters: the acromio-humeral distance in the AP view, the acromial protuberance in the axial view, the subacromial index in a 30degrees caudal tilt view, the acromial type and angle in a supraspinatus outlet view, and the lateral tilting in the image in the oblique coronal MRI. The statistical significance of the differences was determined using the Student t-test.

The average lateral tilting was 17.1degrees for the disease group and 9.6degrees in the control group (P=0.003). The mean lateral tilting was not correlated according to the Bigliani classification or the Neer classification (P<0.05).

An increased lateral tilting in the image of the oblique coronal MRI was found to be a significant predictor of a rotator cuff disease and signifies a rotator cuff at risk.