Effects of Abduction Pillows on Rotator Cuff Repair: A Biomechanical Analysis

Abstract

Background: After rotator cuff repair, some surgeons use abduction pillows to unload or protect the repair construct, while others do not. Question/Purpose: The aim of this study was to determine which type of sling—one with a small or large abduction pillow or one without a pillow—places the repaired rotator cuff in the best position to reduce tension on the supraspinatus. Methods: An X-ray study was performed on asymptomatic subjects to determine what position the shoulder is placed in when wearing a sling with or without an abduction pillow. Positions were then reproduced in human cadaveric shoulders using a custom-made testing jig, and tension on the repaired supraspinatus was measured. Results: X-rays showed that abduction of the glenohumeral joint with a sling was only 4°, with a sling with a small pillow was 13°, and with a sling with a large abduction pillow was 25°. Placing the cadaveric shoulders in the position of a sling with a small abduction pillow caused a reduction in tension on the supraspinatus of 27% anteriorly and 55% posteriorly compared to placing the shoulder in the position of a sling without an abduction pillow; a large abduction pillow caused a further reduction in tension, of 42% anteriorly and 56% posteriorly. Conclusion: These findings show that abduction pillows reduce tension on the repaired supraspinatus tendon.