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

Abstract

After rotator cuff repair, some surgeons use abduction pillows to unload or protect the repair construct, while others do not. 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. 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. 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. These findings show that abduction pillows reduce tension on the repaired supraspinatus tendon.