MR evaluation of factors predicting the development of rotator cuff tears

The purpose of this work was to assess the incidence of various factors predicting impingement in the shoulder. MR examination was used to assess various anatomic parameters in 46 patients with clinical abnormalities of the shoulder and 40 asymptomatic volunteers. All patients had undergone surgery, showing no rotator cuff tear. A few of the parameters evaluated were significantly different in the two groups: The acromion was more frequently curved or hook-shaped in patients than in volunteers. The acromiohumeral distances differed (4.87 mm in patients and 6.05 mm in volunteers); so did the coracohumeral distances (7.9 mm in patients and 8.9 mm in volunteers). The shape of the acromioclavicular joint and the anterior covering of the humerus, defined on the coronal view, also differed (1.07 mm in patients and 1.49 mm in volunteers). Only the shapes of the acromioclavicular joint and of the acromion were linked with age. All these factors reflected a decrease in the acromiohumeral space, except for the anterior covering of the acromial arch, which could be due to anterior instability.