Fixation strength in arthroscopic labral repair of the hip: A head-to-head comparison of the biomechanical performance of a biocompatible vs. all-suture anchor in the setting of acetabuloplasty

Abstract

Much is known about the biomechanical performance of various types of suture anchors commonly used for labral fixation in the shoulder; however, similar studies in the hip are less common. We sought to compare all-suture and polyether ether ketone small-diameter anchors in the setting of labral repair during hip arthroscopy, with and without acetabuloplasty. We hypothesized that the biomechanical properties of the all-suture group when compared to polyether ether ketone anchors would be similar amongst native acetabula and significantly less following acetabuloplasty and that pullout forces would be reduced in the anterior and inferior regions of the acetabulum compared to the superior region. Bone density was measured in nine matched pairs of fresh-frozen cadaveric acetabula in the superior, anterosuperior, and anterior regions. Acetabuloplasty was performed in all three regions, while the contralateral acetabulum was left in situ as a control. Suture anchors were placed such that one each of two different types was placed within each region. Specimens were tested in cyclic fatigue and loaded to failure. The all-suture group had significantly higher cyclic displacement compared to the polyether ether ketone, but there was no significant difference in ultimate load, regardless of acetabuloplasty. Amongst all non-resected specimens, the lowest bone density was observed consistently in the inferior region. Our results indicate that, with or without acetabuloplasty, a small-diameter polyether ether ketone anchor appears to be more stable than an all-suture anchor, which needs to be set first.