摘要
背景:骨折发生发展是个动态过程,传统有限元方法不能很好地预测及展示骨折发生的确切起点、骨质断裂过程及该过程的应力、应变、裂纹扩展情况。目的:模拟不同跌倒载荷速率对股骨颈骨折裂纹扩展的影响。方法:将1名健康志愿者的股骨原始CT数据导入Mimics19.0软件,经区域增长、编辑笼罩、光滑、包裹等重建股骨近端三维有限元模型,并在Hypermesh14.0中进行松质骨、皮质骨网格划分、定义材料属性、设定边界条件、模拟股骨内旋、内收位跌倒状态、加载载荷-时间函数[F1=2500t、F2=(10000/3)t、F3=5 000t、F4=10 000t]等前处理,将生成的K文件导入LS-DYNA求解器中运算。结果与结论:(1)骨折起始裂纹均出现在股骨颈下后方,初始裂纹长度呈载荷速率依赖性;(2)皮质骨断裂时的最大应力均分布在股骨颈后外侧,随着载荷速率升高,应力分布从转子间逐渐向股骨颈缩小;(3)股骨颈的压缩应变主要集中在股骨颈下后方,在裂纹走行处出现最大应变值;(4)载荷速率越高皮质骨越早发生断裂,断裂历程越短,裂纹扩展速率越高,骨折线逐渐变粗糙并上移,形成头下型骨折,同时Pauwels角也随之增大;(5)结果说明,载荷速率会改变股骨颈骨折裂纹扩展行为,进而影响髋部骨折类型。
BACKGROUND: It is a dynamic development in fracture, but the traditional finite element method cannot precisely predict the fracture initiation, crack process, the stress, strain and crack propagation.OBJECTIVE: To simulate and investigate the influence of fall load velocity on crack propagation in femoral neck fracture.METHODS: CT data of femur from a healthy volunteer were collected and imported to Mimics 19.0 software, after region growing, editing,smoothing and wrapping, a three-dimensional finite element model of proximal femur was created. The primary model was imported in Hypermesh 14.0 for meshing of trabecular and cortical bone, defining material properties, setting boundary conditions, simulating fall in internal rotation and adduction, and loaded with load-time function(F1=2 500 t;F2=(10 000/3)t;F3=5 000 t;F4=10 000 t). The integrated K file was finally calculated in LS-DYNA.RESULTS AND CONCLUSION:(1) The initial crack started at the inferior-posterior of femoral neck with a velocity-dependent manner in primary length.(2) The maximum stress distributed on the inferior-posterior of femoral neck but with a negative correlation between loading velocity in distributing region from intertrochanteric to neck.(3) The compressive strain mainly demonstrated on the inferior-posterior of femoral neck that consistent with the propagation of crack.(4) Higher the loading rate was, earlier the damage began, fewer the time needed to fracture, faster the crack developed, and rougher the fracture line were and larger the Pauwels angle formed.(5) In summary, fall loading rate is an important exogenous factor in femoral neck fracture propagation, which affects hip fracture types.
作者
郑利钦
林梓凌
陈心敏
梁子毅
李木生
郑永泽
Zheng Liqin;Lin Ziling;Chen Xinmin;Liang Ziyi;Li Musheng;Zheng Yongze(First School of Clinical Medicine of Guangzhou University of Chinese Medicine,Guangzhou 510405,Guangdong Province,China;Department of Traumatic Orthopedics,First Affiliated Hospital of Guangzhou University of Chinese Medicine,Guangzhou 510405,Guangdong Province,China;Lingnan Medical Research Center of Guangzhou University of Chinese Medicine,Guangzhou 510405,Guangdong Province,China)
出处
《中国组织工程研究》
CAS
北大核心
2019年第20期3148-3152,共5页
Chinese Journal of Tissue Engineering Research
基金
国家自然科学基金项目(81673996)
项目负责人:林梓凌~~
关键词
跌倒载荷速率
股骨颈骨折
裂纹扩展
断裂力学
有限元
跌倒
CT数据
股骨头下骨折
fall load velocity
femoral neck fracture
crack propagation
fracture mechanics
finite element
fall
CT data
subfemoral fracture
