【摘要】 目的 探讨常规放疗对钛合金内固定物力学性能和生物相容性的影响，为放疗在钛合金内固定患者中的使用提供理论依据，并探讨由放疗导致骨肿瘤患者内固定失败的可能原因。方法 采用临床常用的钛合金内固定物，模拟临床常规分次放疗方案，实验组每日接受1次放疗，连续5 d，总剂量为40 Gy（分次剂量8 Gy/次），对照组置于相同环境但不进行照射。通过扫描电镜（SEM）评估放疗对内固定物微结构的改变，通过三点弯曲测试及细胞毒性检测评估放疗对内固定物力学性能及生物相容性的影响。结果 (1)SEM显示：放疗后实验组与对照组的内固定物表面形貌（如晶粒分布、孔隙形态）无明显差异；模拟体液环境浸泡后，实验组与对照组表面形貌表现为均匀的浅层腐蚀，内部可见延展性断裂。能谱分析（EDS）表明：两组样品的主要元素组成（Ti、Al、O、V）比较，差异无统计学意义（P>0.05）。(2)三点弯曲测试中两组的刚度、屈服载荷和弯曲强度比较，差异无统计学意义（P>0.05），这表明常规放疗不会引发内固定物力学性能改变。(3)细胞毒性检测显示：在100%、75%、50%和25%浓度的内固定物浸提液中，两组的L929细胞存活率比较，差异无统计学意义（P>0.05），这表明常规放疗不会改变内固定物的生物相容性。结论 常规放疗不会改变钛合金内固定物的微结构，不影响其力学性能和生物相容性。因此临床常规分次放疗（40 Gy/5f）可以用于体内有钛合金内固定物的患者，为骨肿瘤患者内固定术后放疗的安全性评估提供了直接的实验依据。更多还原

【Abstract】 Objective To investigate the effects of conventional radiotherapy on the mechanical properties and biocompatibility of titanium alloy internal fixators, thereby providing a theoretical basis for the application of radiotherapy in patients with titanium alloy implants, and to explore the potential causes of internal fixation failure in bone tumor patients following radiotherapy. Methods Clinically utilized titanium alloy internal fixators were divided into experimental and control groups. The experimental group received daily radiotherapy(8 Gy per fraction, total dose: 40 Gy over 5 days) to simulate a conventional clinical fractionated radiotherapy regimen, while the control group was maintained under identical environmental conditions without irradiation. Scanning electron microscopy(SEM) was employed to evaluate radiotherapy-induced microstructural alterations. Three-point bending tests and cytotoxicity assays were conducted to assess the effects of radiotherapy on mechanical properties and biocompatibility of the fixators. Results(1) SEM analysis revealed no significant differences in surface morphology(e.g., grain distribution, pore structure) between the irradiated and control groups. After immersion in simulated body fluid, both groups exhibited uniform shallow surface corrosion and internal ductile fracture patterns. Energy-dispersive X-ray spectroscopy(EDS) showed no statistically significant differences in elemental composition(Ti, Al, O, V) between groups(P>0.05).(2)Three-point bending tests demonstrated no statistically significant differences in stiffness(P=0.082), yield load(P=0.83), or bending strength(P=0.83) between groups, indicating that conventional-dose radiotherapy did not alter mechanical integrity.(3)Cytotoxicity assays revealed no statistically significant differences in L929 cell viability across 100%, 75%, 50%, or 25% concentrations of fixator extracts(P>0.05), confirming preserved biocompatibility postradiotherapy. Conclusion Conventional fractionated radiotherapy(40 Gy/5f) does not alter the microstructure of titanium alloy internal fixators and has no adverse effects on their mechanical properties or biocompatibility. Therefore, conventional fractionated radiotherapy at 40 Gy in 5 fractions can be safely applied to patients with titanium alloy internal fixators, providing direct experimental evidence to support the safety evaluation of postoperative radiotherapy in bone tumor patients undergoing internal fixation.更多还原