摘要
目的探讨不同角度载荷对股骨头骨小梁形态学与力学性能的影响,为研究股骨头坏死、塌陷的生物力学机制提供理论依据。方法利用12月龄羊股骨头和人尸体股骨头分别制作羊股骨头骨小梁试件94个和人股骨头骨小梁试件43个。按照受力方向与骨小梁主压力方向之间的不同夹角,将骨小梁以10°间隔分为内翻10°、0°和外翻10°、20°、30°共计5组,模拟股骨颈骨折内固定术后不同戈登(Garden)对线指数下的复位情况。通过分别对羊股骨头骨小梁进行micro-CT扫描、计算与压缩破坏试验以及对人尸体股骨头骨小梁进行循环压缩试验,分析不同受力方向下股骨头骨小梁的骨体积分数(BV/TV)、骨表面积/骨体积(BS/BV)、骨小梁平均厚度(Tb.Th)、骨小梁数量(Tb.N)、骨小梁间距(Tb.Sp)等形态学指标以及弹性模量、极限强度、屈服强度、初始弹性模量、循环次数等力学指标。结果加载方向与骨小梁的主压力方向之间夹角为0°时,BV/TV、Tb.Th以及弹性模量、极限强度、屈服强度、初始弹性模量、循环次数均为最大,而BS/BV与Tb.N为最小,并随着夹角增大前者呈递减而后者呈递增趋势。结论 12月龄羊股骨头骨小梁BV/TV与极限强度随受力方向与骨小梁主压力方向之间夹角变化的趋势与人股骨头骨小梁一致;加载方向与主压力骨小梁之间夹角增大时,股骨头骨小梁形态学与力学性能均下降;Garden指数偏离160°越大时,股骨头内骨小梁越易发生损伤。
Objective To investigate the effects from loads with different angles on morphological and biomechanical properties of trabecular bones in femoral head, so as to provide theoretical basis for studying biomechanical mechanism of necrosis and collapse of femoral head. Methods Ninety-four specimens of 12-month-old ovine trabecular bones in femoral head and forty-three specimens of human cadaver trabecular bones in femoral head were prepared. According to different angles between loading direction and principle compression direction, all the trabecular bones were divided into five groups by 10° interval （i.e. varus 10° and 0°, valgus 10°, 20° and 30°） to simulate the reduction condition under different Garden index after internal fixation of femoral neck fractures. Micro-CT scanning and calculation, compression failure test on ovine trabecular bones in femoral head and cyclic compression test on human cadaver trabecular bones in femoral head were performed to investigate morphological and mechanical indices, including BV/TV （bone volume vs. total volume）, BS/BV （bone surface vs. bone volume）, Tb.Th （thickness of trabecular bone）, Tb.N （number of trabecular bone）, Tb.Sp （trabecular separation）, elastic modulus, ultimate strength, yield strength, initial secant modulus and number of cycles. Results When the angle between loading direction and principle compression direction of trabecular bones was 0°, BV/TV, Tb.Th, elastic modulus, ultimate strength, yield strength, initial secant modulus and number of cycles for trabecular bones were the maximum while BS/BV and Tb.N were the minimum, and all the formers presented decreasing tendency while BS/BV and Tb.N showed increasing tendency along with the angle increasing. ConclusionsAlong with the angle changes, the tendency of BV/TV and ultimate strength for 12-month-old ovine trabecular bones in femoral head displayed as the same as human trabecular bones in femoral head. Both the morphological and biomechanical properties of trabecular bones in
出处
《医用生物力学》
EI
CAS
CSCD
北大核心
2015年第6期521-527,共7页
Journal of Medical Biomechanics
基金
天津市卫生局科技基金项目(2014KY31)
天津市科技支撑重点项目(13ZCZDSY01700)
国家自然科学基金项目(81102607)
