摘要
背景:近年来,生物可降解锌合金接骨板可有效解决钛合金接骨板应力屏蔽效应大、需手术二次取出等临床问题而受到广泛研究。影响接骨板应力遮蔽效应的主要因素包括接骨板的结构设计、材料选择和降解速度等,然而有关生物可降解锌合金接骨板结构设计与应力遮蔽效应关系的研究较少,并且缺乏科学依据。目的:探索生物可降解锌合金接骨板结构设计与应力遮蔽效应的关系。方法:使用普通锌镁合金接骨板固定新西兰兔胫骨骨折,术后3,6,9,12个月取出接骨板,分析材料降解率。设计关于接骨板厚度、螺钉孔径、开弧直径和开孔直径等4个参数与接骨板应力的正交实验,基于构建的数据集,采用回归分析建立4种参数与锌镁合金接骨板应力的预测模型,根据不同约束条件得到接骨板设计的最优参数。采用有限元分析对比优化设计前后的锌镁合金接骨板与钛合金接骨板在兔胫骨骨折模型中的生物力学性能。结果与结论:①植入兔体内后,锌镁合金接骨板表面有明显腐蚀现象,并且随着时间推移腐蚀程度逐渐加深;与植入前相比,锌镁合金接骨板植入后3,6,9,12个月的降解率分别为11.5%,17.9%,21.8%和24.5%。②通过回归模型得出接骨板理论最优结构参数:接骨板厚度1.1 mm,螺钉孔径2.4 mm,开孔直径0.6 mm,开弧直径6.0 mm。③有限元分析结果显示,优化前和优化后的锌镁合金接骨板、钛合金接骨板在复合工况下所受的最大应力均小于其屈服强度,初始固定时,优化前、优化后钛合金接骨板组骨折段端位移分别为0.08 mm和0.12 mm,优化前、优化后锌镁合金接骨板组骨折段端位移分别为0.10 mm和0.13 mm;降解3个月后,优化前、优化后锌镁合金接骨板组骨折段端位移分别为和0.11 mm和0.15 mm,两种接骨板治疗兔胫骨骨折理论上均是安全的。与钛合金接骨板相比,锌镁合金接骨板表现出较低的应力遮蔽效应;随着降解,优化前、优化后锌镁合金接骨板组应力遮挡率分别下降了27.56%和27.66%。结果表明,锌镁合金接骨板在早期阶段提供力学支撑,在后期随着材料降解降低应力遮挡效应,从而有利于骨愈合。
BACKGROUND:In recent years,biodegradable zinc alloy bone plates could effectively solve the clinical problems such as stress shielding effect and secondary surgical removal.The main factors that affect the stress shielding of biodegradable bone plates include the structural design,material selection,and degradation rate.However,the relationship between the structural design and stress shielding effect of biodegradable zinc alloy bone plates is rarely studied,and there is a lack of scientific basis.OBJECTIVE:To explore the relationship between the structural design of biodegradable zinc alloy plates and the stress shielding effect.METHODS:Ordinary zinc-magnesium alloy plates were used to fix tibial fractures in New Zealand rabbits.The plates were removed 3,6,9,and 12 months after surgery,and the material degradation rate was analyzed.An orthogonal experiment was designed to compare the four parameters of plate thickness,screw hole diameter,arc diameter,and hole diameter with plate stress.Based on the constructed data set,a prediction model of the four parameters and zincmagnesium alloy plate stress was established by regression analysis.The optimal parameters of plate design were obtained according to different constraints.Finite element analysis was used to compare the biomechanical properties of zinc-magnesium alloy plates and titanium alloy plates before and after optimization design in a rabbit tibial fracture model.RESULTS AND CONCLUSION:(1)After implantation in rabbits,the surface of the zinc-magnesium alloy plate showed obvious corrosion,and the degree of corrosion gradually deepened over time.Compared with before implantation,the degradation rates of the zinc-magnesium alloy plate were 11.5%,17.9%,21.8%,and 24.5%at 3,6,9,and 12 months after implantation,respectively.(2)The optimal theoretical structural parameters of the plate were obtained by regression model:plate thickness 1.1 mm,screw hole diameter 2.4 mm,hole diameter 0.6 mm,arc diameter 6.0 mm.(3)The results of finite element analysis showed that the maximum stresses of the zinc-magnesium alloy plate and titanium alloy plate before and after optimization were less than their yield strength under the composite working conditions.During the initial fixation,the displacement of the fracture end of the titanium alloy plate group before and after optimization was 0.08 mm and 0.12 mm,respectively.The displacement of the fracture end of the zinc-magnesium alloy plate group before and after optimization was 0.10 mm and 0.13 mm,respectively.After 3 months of degradation,the displacement of the fracture end of the zinc-magnesium alloy plate group before and after optimization was 0.11 mm and 0.15 mm,respectively.Both plates were theoretically safe for the treatment of rabbit tibial fractures.Compared with the titanium alloy plate,the zinc-magnesium alloy plate exhibited a lower stress shielding effect.With degradation,the stress shielding rates of the zinc-magnesium alloy plate group before and after optimization decreased by 27.56%and 27.66%,respectively.The results exhibit that the zinc-magnesium alloy plate provides mechanical support in the early stage,and reduces the stress shielding effect in the later stage as the material degraded,which is beneficial to bone healing.
作者
张天蔚
韩兴元
张佃明
李荣华
赵德伟
Zhang Tianwei;Han Xingyuan;Zhang Dianming;Li Ronghua;Zhao Dewei(College of Mechanical Engineering,Dalian Jiaotong University,Dalian 116028,Liaoning Province,China;National and Local Joint Engineering Laboratory for Orthopedical Implants,Dalian 116200,Liaoning Province,China)
出处
《中国组织工程研究》
北大核心
2026年第14期3485-3493,共9页
Chinese Journal of Tissue Engineering Research
基金
国家骨科与运动康复临床医学研究中心创新基金项目(2021-NCRC-CXJJ-ZH-28),项目负责人:赵德伟。
关键词
生物可降解锌镁合金
钛合金
骨折内固定系统
回归分析
有限元分析
工程化骨科材料
biodegradable zinc-magnesium alloy
titanium alloy
fracture internal fixation system
regression analysis
finite element analysis
engineered orthopedic material
作者简介
第一作者:张天蔚,男,1987年生,黑龙江省哈尔滨市人,汉族,博士,主治医师,主要从事关节外科的基础和临床工作,目前主要从事生物材料在骨科中的应用研究。https://orcid.org/0009-0003-4710-2610;通讯作者:赵德伟,博士,教授,大连交通大学机械工程学院,辽宁省大连市116028,大连大学附属中山医院骨科植入材料开发国家地方联合工程实验室,辽宁省大连市116200。
