糖皮质激素性骨量减少患者股骨头骨小梁微结构改变

Femoral head microstructure in steroid-induced osteopenia patients

目的测量糖皮质激素所致骨量丢失进程中骨微结构参数的改变,了解糖皮质激素所诱发的骨质疏松较之原发性骨质疏松更易发生骨折的骨微形态结构方面的原因。方法取26例老年女性患者股骨头标本,其中18例来源于有应用糖皮质激素史、骨量减少患者,8例来源于绝经后严重骨质疏松症患者。应用三维微聚焦计算机X线断层扫描(μCT)技术测量松质骨显微结构参数,采用Pearson相关分析研究参数间相关性、独立样本t检验比较两组间显微结构参数差异,分析与糖皮质激素作用下骨力学强度下降相关的主要参数。结果与严重骨质疏松症患者相比,激素性骨量减少患者骨小梁体积分数(BV/TV)、骨表面积分数(BS/BV)均明显较大(P<0.05);骨小梁厚度(Tb.Th)显著降低(P<0.05);结构模型指数(SMI)明显升高(P<0.05);骨小梁分离度(Tb.Sp)较低(P<0.05),但骨小梁连接处断点(端)有增加趋势。结论糖皮质激素可促使柱状结构的骨小梁减少而多呈扁平状和(或)杆状,骨小梁间断点多发,这是造成骨量减少状态下骨生物力学性能迅速下降、发生类似严重骨质疏松症易发骨折的原因之一;糖皮质激素应用对骨组织微结构的损害程度大于所致骨量降低程度。

Objective To elucidate the reason why glucocorticoid induced hone lose could fragility and higher incidence of fracture compared to primary osteoporosis through the parameters. Methods Femoral heads from twenty-six elderly female patients were collected. Among the patients, eighteen have a history of taking glucocorticoids with bone mass decreasing, and the rest suffer from severe postmenopausal osteoporosis. frabecular microstruclure parameters were calculated by micro-computed tomography. Pearson＇s correlation coefficients and Student＇s t lest were used to analyze the correlation and significant differences of the major bone microstructural parameters between glucoeorticoids induced osteoporosis and postmenopausal osteoporosis. Results In comparison to primary osteoporosis, glucocorticoid induced osteoporosis patients had significantly higher （P〈0.05） cancellous bone volume （BV/TV）, bone surface to volume ratk） （BS/BV） and structure model index （SMI）, while their trabecular thickness （Tb. Th） and trabecular separation （Tb. Sp） were significantly lower （P〈0.05）. Conclusion In glucocorticoid induced osteoporosis patients, the morphology of the lrabeculae changed from columnar to flat or rod shaped and the fragmentation of the bone trabecular network was higher. Glucocorticoids induced loss of bone strength was far greater than the degree of reduction in bone mass. Therefore, glucocorticoids induce more deterioratinn in the biomechanical strength of the hone and the patients are prone to fractured compared to primary osteoporosis.