目的 研究可降解镁合金接骨板修复骨折过程中的降解行为及力学性能。方法 将36只成年新西兰兔随机分为实验组(镁合金接骨板组)及对照组(钛合金接骨板组),分别利用镁合金接骨板及钛合金接骨板进行骨折固定。术后通过X线片检查、扫描电镜检查、能谱分析、失重试验及四点弯曲试验,评价镁合金接骨板修复骨折过程中的降解行为及力学性能变化规律。结果 X线片显示镁合金接骨板在体内可逐渐降解；扫描电镜、能谱分析及失重试验结果显示镁合金接骨板随着体内植入时间延长,其降解逐渐加深,且其表面为均匀腐蚀；四点弯曲试验结果显示镁合金接骨板随着降解过程的加深力学性能逐渐减弱。结论 镁合金接骨板在骨折愈合过程中可逐渐降解,在降解过程中其力学性能逐渐衰减。
Objective To study the degradation behavior and mechanical properties of magnesium alloy plate on treatment of tibial fracture in New Zealand rabbits. Methods 36 adult New Zealand rabbits were randomly divided into experimental group (magnesium alloy plate group) and control group (titanium alloy plate group). Tibial fractures in experimental group and control group were fixed with magnesium alloy plate and titanium alloy plate respectively. After operation, X-ray, scanning electron microscopy, energy spectrum analysis, weight loss test and four-point bending test were performed in each group to analyze the the degradation behavior and mechanical properties of magnesium alloy plate on treatment of tibial fracture in New Zealand rabbits. Results X-ray showed that magnesium alloy plate can be degraded gradually in vivo. Scanning electron microscope, energy spectrum analysis and weight loss test results showed that the degradation of magnesium alloy plate was deepened gradually with the implantation time, and the surface was corroded uniformly. The four-point bending test results showed that the mechanical properties of magnesium alloy plate decreased gradually with the degradation in vivo. Conclusion Magnesium alloy plate can be degraded gradually in the process of fracture healing, and its mechanical properties weaken gradually during the degradation in vivo.