Our purpose is to evaluate the relation between the tension of the repaired rotator cuff, size of the tear, linear bands of the supraspinatus muscle scanned by MRI, and postoperative JOA score. The subjects were 18 patients (15 males, 3 females) with rotator cuff tear of the shoulder aged 52 to 74 years. We measured the tension of the repaired rotator cuff at the arm at the 0°, 30°, 60° abduction positions using a simple spring scale, and we classified into three grades the linear bands of the supraspinatus by MRI. As a result, there were two grade 1 shoulders, six grade 2 shoulders, and ten grade 3 shoulders. The larger tears require higher tension repair, in particular the tension when the arm was elevated by 30° and size of the tear were found to be related. No significant difference was seen between the size of the tear and the JOA score in this study for every grade.
