Study on the Performance and Ligament-Bone Tissue Repair of Assembled Magnesium Alloy Suture Anchor

Biodegradable magnesium and its alloys have shown potential in promoting tendon-bone healing, making them promising materials for suture anchors. However, the rapid degradation of anchor holes leading to loss of mechanical strength has not been fully addressed in anchor design. In this study, we proposed a novel assembled structure magnesium alloy suture anchor that effectively mitigates failure due to excessive degradation of the anchor holes. Finite element simulations were employed to adjust structural parameters. And in vitro and in vivo experiments were conducted to evaluate its mechanical properties, degradation behavior and effects on ligament-bone tissue repair. In vitro , mechanical tests demonstrated that the assembled magnesium alloy suture anchor was self-tapping and provided stable fixation. Soaking tests showed that the outer surface of the assembled magnesium alloy suture anchor degraded gradually. While the anchor holes degraded more slowly, entering the initial degradation stage after two weeks. In vivo , the assembled suture anchor maintained its mechanical integrity for 12 weeks post-surgery, with relatively uniform degradation over time. The degradation rate of the anchor hole was slower than the average degradation rate of the entire anchor. Imaging and histological analyses demonstrated good bone integration around the anchor and favorable regeneration of the fibrocartilage at the ligament-bone junction. Furthermore, fracture strength of the anchor remained 146.70±7.29 N at 12 weeks post-surgery, ensuring reliable fixation strength. This study provides a foundation for further design and research of biodegradable magnesium alloy suture anchors for clinical applications.