Influence of Temperature on the Biomechanical Stability of Titanium, PEEK, Poly-L-Lactic Acid, and β-Tricalcium Phosphate Poly-L-Lactic Acid Suture Anchors Tested on Human Humeri In Vitro in a Wet Environment

Purpose: The purpose of this study was to analyze the biomechanical integrity of suture anchors of different materials (titanium, PEEK [polyether ether ketone], poly-L-lactic acid [PLLA], and beta-tricalcium phosphate PLLA) and almost identical design for rotator cuff repair in human humeri positioned in a water bath at room and body temperature undergoing cyclic loading rather than single-pull or static tests. Methods: Four different anchor models (n = 6) were tested using healthy human cadaveric humeri in a water bath thermostatically regulated at 20 degrees C and 37 degrees C. A cyclic testing protocol was used. The maximum failure load, the system displacement, and the respective mode of failure were recorded. Results: There were no significant differences regarding the maximum failure load values between the 20 degrees C groups and 37 degrees C groups for the 4 different anchor materials. The displacement values for the 20 degrees C groups and 37 degrees C groups also were not statistically significant. Anchor and suture dislocations were the predominant modes of failure; suture ruptures were observed in few cases. Conclusions: This study shows that there are no significantly relevant differences regarding the maximum failure loads and the displacement values of the tested suture anchor systems in a wet environment at 20 degrees C or 37 degrees C. The temperature differences do not seem to affect the modes of failure either.