A rupture of the rotator cuff tendon may induce muscular fatty degeneration, which can be observed with computed tomography (CT) imaging. The purpose of this study was to examine the frequency of fatty degeneration in patients with a complete rotator cuff tear using CT images.
Twenty shoulders in twenty eight patients (average age sixty point seven years old ) with a complete cuff tear were studied. Fatty degeneration was evaluated using CT images and assessed by Goutallier's classification. The diagnosis of rotator cuff tear was made by the examiner, after which the frequency of fatty degeneration was determined. Supraspinatus tendon ruptures were found in eleven patients, infraspinatus tendon ruptures in two, supraspinatus and infraspinatus tendon ruptures in six, supraspinatus and subscapularis tendon ruptures in eight, and all three tendons were found ruptured in three. The frequency of fatty degeneration in the infraspinatus tendon was 66.7%, while that in the supraspinatus and subscapularis tendons was 35.7% and 23.1%, respectively. Some reports have concluded that postoperative results for rotator cuff repair are inferior when fatty degeneration has occurred, thus, it is best if surgery can be performed prior to its appearance. From the results of the present study, we considered that fatty degeneration is more prevalent with the infraspinatus tendon. Therefore, when a rupture of the this tendon is suspected, an operation should be carried out as soon as possible.
