Strength of single- versus double-anchor repair of type II SLAP lesions: a cadaveric study.

Abstract

This study was designed to examine whether there was a difference in pullout strength along with the mode of failure between 1 suture anchor and 2 suture anchors. Ten matched pairs of cadaveric shoulders were used in the study. A type II SLAP lesion, according to the classification of Snyder et al., was created. In 10 shoulders 1 anchor with 2 sutures was used to repair the lesion. In the other group of 10 matched shoulders, fixation was done with 2 anchors, with each anchor having only 1 suture. An Instron servohydraulic test machine (Instron, Canton, MA) was used to pull the long head of the biceps tendon until failure occurred. The single-anchor group failed at a mean load of 278.5 +/- 101.5 N. The double-anchor group failed at 242.5 +/- 96.5 N. A paired 2-sample Student t test showed that there was no significant difference in pullout strength between the 2 groups (P = .090). The most common mode of failure was soft-tissue failure. There was 1 anchor pullout in the single-anchor group and 2 anchor pullouts in the double-anchor group. The results of this study imply that using 1 anchor with 2 sutures is biomechanically equivalent to 2 anchors with 1 suture each for repairing type II SLAP lesions. Using 1 suture anchor is sufficient to repair a type II SLAP lesion.