The purpose of this study was to address the influence of the tension of a rotator cuff repair on the postsurgical outcome and the shoulder abduction strength. Twenty-seven cases underwent a primary rotator cuff repair. Six cases were excluded due to a retear and bilateral rotator cuff tear. There were 20 males and 7 females. The mean age at operation was 63 (46-79) years old. At the time of repair, an osseous trough was created in the greater tuberosity. Then, the tension that the torn tendon cuff was attached to the trough was measured with a spring balance. Three measurements were taken at 0°and 30°of shoulder abduction. The JOA score and the postoperative isometric shoulder abduction strength were examined with a micro FET at average 26 (6-50) months in the follow-up. There was no correlation between the tension of rotator cuff repair and the JOA score. There was a strong positive correlation between the postoperative abduction strength and the tension of less than 3kg at 30°abduction (avr.: 94.5%, correlation coefficient:; 0.755), and a strong negative correlation between that strength and that with more than 3kg (avr.: 88.2%, correlation coefficient:; -0.837). If the tension of the torn cuff tendon showed about 3kg at the time of repair, the postoperative shoulder abduction strength might be restored very well.
