Suture anchor fixation strength in osteopenic versus non-osteopenic bone for rotator cuff repair

Abstract

Rotator cuff tears are increasing with age. Does osteopenic bone have an influence on the pullout strength of suture anchors? SPIRALOK 5.0 mm (DePuy Mitek), Super Revo 5 mm and UltraSorb (both ConMed Linvatec) suture anchors were tested in six osteopenic and six healthy human cadaveric humeri. Incremental cyclic loading was performed. The ultimate failure load, anchor displacement, and the mode of failure were recorded. In the non-osteopenic bone group, the absorbable SPIRALOK 5.0 mm achieved a significantly better pullout strength (274 N +/- 29 N, mean +/- SD) than the titanium anchor Super Revo 5 mm (188 N +/- 34 N, mean +/- SD), and the tilting anchor UltraSorb (192 N +/- 34 N, mean +/- SD). In the osteopenic bone group no significant difference in the pullout strength was found. The failure mechanisms, such as anchor pullout, rupture at eyelet, suture breakage and breakage of eyelet, varied between the anchors. The present study demonstrates that, in osteopenic bone, absorbable suture anchors do not have lower pullout strengths than metal anchors. In normal bone, the bioabsorbable anchor in this study even outperformed the non-absorbable anchor.