摘要
目的观察骨质疏松和正常状态下椎体松质骨的微观结构改变,分析其对骨生物力学的影响。方法将12只4月龄雌性Lewis大鼠随机分为去卵巢组(OVX)组和假手术组(Sham),每组各6只。OVX组行双侧卵巢切除术,假手术组仅显露双侧卵巢。术后6个月处死动物,取尾椎(L_(4-7))行Micro-CT分析及生物力学测试。结果去卵巢6个月后,OVX组大鼠体积骨密度(vBMD)和组织骨密度(tBMD)较Sham组显著降低,松质骨骨小梁的骨体积分数(BV/TV)和数目(TB.N)都明显低于Sham组,骨小粱表面积密度(BS/BV)、结构模拟指数(SMI)和间距(Tb.Sp)显著高于Sham组,差异有统计学意义。但2组间骨小梁厚度(Tb.Th)差异无统计学意义。生物力学测试结果表明,去势6个月后,OVX组大鼠骨质生物力学性能显著下降。骨小梁力学性能与骨小梁体积分数(Adjusted R^2=0.750和数目(Adjusted R^2=0.861)呈正线性相关,而与结构模拟指数(Adjusted R^2=0.716)和骨小梁间距(Adjusted R^2=0.830)呈负线性相关。结论松质骨骨小梁微观结构的改变可影响骨质的生物力学性能,二者之间具有一定的线性关系。
To observe the microstructure of osteoporosis and normal trabeeular bone and its effect on bone biomechanics. 4-month Lewis rats were randomly divided into OVX or sham group, each group has 6 animals, respectively. After 6 months of operation, all rats were sacrificed. The caudal vertebral were harvested and reconstructed by Micro-CT. In biomechanical evaluation, the axial failure test was accomplished on the caudal vertebrae. The volumetric BMD （vBMD） and tBMD of OVX group decreased significantly than that of sham group （ P 〈0. 01 ）. The bone volume fraction （BV/TV） and trabecular number （Tb. N） in OVX group also decreased significantly, while the bone area density （BS/BV）, structure model index （SMI） and trabecular space （Tb. SP） significantly increased （P 〈0. 05）. Furthermore, the trabecular thickness （Tb. Th） had no significant difference in two groups. In biomechanical test, the maximum compressing strength and stiffness of trabecular bone in OVX group were lower than that in Sham group. The BV/TV and Tb. N were positive correlated with the strength and stiffness. Furthermore, SMI and Tb. SP were negative correlated with the strength and stiffness. The microstructure of trabecular bone affected its biomechanical properties. There are some correlations between micrestructure and biomechanical properties.
出处
《中华骨质疏松和骨矿盐疾病杂志》
2010年第3期194-199,共6页
Chinese Journal Of Osteoporosis And Bone Mineral Research
