摘要
目的应用显微CT和微有限元分析评估微损伤、微骨折骨小梁的应力、应变,探讨骨质疏松症对骨小梁应力和微损伤、微骨折之间关系的影响。方法通过显微CT扫描健康和骨质疏松人体髋臼松质骨,构建松质骨块三维微有限元模型,在无摩擦的位移边界条件下模拟松质骨块的单轴压缩实验,通过非线性微有限元分析得到在不同表观应变下骨小梁的应力、应变、微损伤和微骨折。结果 0.05%-0.50%表观应变下,健康和骨质疏松松质骨未损伤骨小梁的应力在50 MPa以下,微损伤骨小梁应力在110 MPa以上。健康松质骨骨小梁的平均应力相对较高,骨质疏松松质骨骨小梁最高应力值相对较高。健康和骨质疏松松质骨骨小梁均出现微损伤,健康松质骨骨小梁微损伤较多,骨质疏松骨骨小梁出现微骨折。结论在表观小应变范围内,健康松质骨骨小梁能承受更高的应力,出现较多的微损伤,而骨质疏松松质骨高应力骨小梁群内出现微骨折。
Objective To quantify the stress and strain of trabecular bone with microdamage / microfracture by using micro-CT and micro-finite element（ μFE） analysis,so as to investigate the effects of osteoporosis on relationship between trabecular stress and microdamage / microfracture. Methods Two cylindrical specimens of healthy and osteoporotic acetabular trabecular bones were scanned by micro-CT to build 3D μFE analysis models. The uniaxial compression on two specimens was simulated under frictionless displacement boundary condition. The trabecular stress,trabecular strain,microdamage and microfracture under different apparent strains were calculated through nonlinear μFE analysis. Results For both the healthy and osteoporotic trabeculae under apparent strain of 0. 05%-0. 50%,the undamaged trabecular stress was under 50 MPa,while the damaged trabecular stress was above 110 MPa. Compared with the osteoporotic trabeculae,the mean stress of the healthy trabeculae was relatively higher,but the maximum stress of the osteoporotic trabeculae was higher. Trabecular damage occurred in both the healthy and osteoporotic trabeculae,while the healthy trabeculae showed more microdamage,and microfracture occurred in the osteoporotic trabeculae. Conclusions Within the scope of apparent strain,the healthy trabeculae can withstand a higher stress with more trabecular microdamage,and microfractures might occur in the osteoporotic trabeculae under the high stress.
出处
《医用生物力学》
EI
CAS
CSCD
北大核心
2015年第1期68-74,共7页
Journal of Medical Biomechanics
基金
国家高科技发展计划(2006AA02A137)
上海交通大学博士创新基金(BXJ0730)
关键词
骨小梁
显微CT
有限元分析
骨质疏松
微损伤
应力
Trabecula
Micro-CT
Finite element analysis
Osteoporosis
Microdamage
Stress
