Biomechanical Analysis of Medial-Row All-Suture Suture Anchor Fixation for Rotator Cuff Repair in a Pair-Matched Cadaveric Model

Abstract

To compare the biomechanical properties of all-suture suture anchors (ASSAs) with conventional suture anchors (CSAs) for double-row rotator cuff repair (RCR). Fourteen fresh-frozen human cadaveric shoulders were randomized into 2 RCR treatment groups: ASSA and CSA. All constructs received a double-row repair, with the lateral-row implants consisting of two 5.5-mm PEEK (polyether ether ketone) Footprint anchors. Each construct was loaded to a 10-N preload for 2minutes, followed by cyclic loading from 10 to 160N at a rate of 100N/s for 100 cycles. Load-to-failure testing was performed immediately after cyclic loading testing at 1mm/s from the zero position until failure. Cyclic creep, elongation amplitude, maximum load, stiffness, energy, and failure mode were recorded. No significant difference in cyclic creep (P= .117) or elongation amplitude (P= .428) was found between the ASSA and CSA groups during cyclic testing. Three specimens in each group (43% in each) failed by the suture tearing through the tendon. The remaining specimens in each group failed by the anchor pulling out of the humeral head. The mean maximum load was 617.73 ± 177.77N and 545.13 ± 212.98N for the ASSA and CSA groups, respectively (P= .339). Maximum elongation before failurewas not different between groups (P= .122). Mean energy and stiffness were not statistically different between the ASSA and CSA groups (P= .629 and P= .973, respectively). In this cadaveric analysis with a simplified unidirectional experimental setup, failure mechanics and maximum load between the ASSA and CSA constructs were similar, with no difference in energy and stiffness. Although the ASSA group showed slightly larger elongation thanthe CSA group, these differences may not be clinically relevant. This study provides a biomechanical head-to-head comparison of ASSAs and CSAs, indicating that ASSAs may be clinically equivalent to CSAs for use in an RCR.