Time-dependent reduction in load to failure of wedge-type polyglyconate suture anchors

Thirty-two absorbable (polyglyconate) and 24 nonabsorbable (polyacetal) wedge-type suture anchors (TAG; Acufex, Mansfield, MA) were implanted into sheep tibiae. Load to failure tests were performed on the day of insertion and at weeks 3, 6, and 12, followed by macroscopic examination. Failure type was suture breakage for nonabsorbable anchors in all groups, with average forces of 142.5 +/- 4.8 N on the first day, 138.0 +/- 6.6 N in week 6, and 135.6 +/- 2.9 N in week 12. In the absorbable group, suture breakage occurred on the first day with a mean force of 133.5 +/- 4. 2 N. In weeks 3, 6, and 12, suture cutout occurred with average forces of 33.75 +/- 5.0 N, 23.25 +/- 2.2 N, and 23.25 +/- 5.9 N, respectively. For absorbable anchors, results at weeks 3, 6, and 12 were significantly lower compared with initial results (P <.001). These results show that wedge-type polyglyconate anchors lose 75% of their initial pullout strength within the first 3 weeks and 84% in 6 weeks.