牵张成骨中骨密度测定方法的研究

目的:研究兔牵张成骨过程中骨密度的变化,并对骨密度新型测量方法评定。方法:日本大耳白兔24只,随机分为空白对照组、牵张术后1 d、1周、2周、4周、6周组,每组4只。随机选取一侧下颌骨行牵张成骨术。处死后的兔游离下颌骨根据阿基米德原理行骨密度测量、单能X线骨密度仪测量和钙含量测定,利用SPSS 19.0统计软件分析各组骨密度的差异并通过单能X线骨密度标准评定阿基米德原理测量骨密度值方法,分析骨密度与钙含量的相关性。结果:阿基米德原理骨密度测量、单能X线骨密度仪测量和钙含量测定均显示牵张区骨密度和钙含量逐渐增加,6周组与对照组无显著性差异,基本接近正常骨密度和钙含量,且变化趋势相同。阿基米德原理骨密度测量与单能X线骨密度仪测量正性相关,回归方程:Y_单能X线=-0.227+0.457X_阿基米德;骨密度与钙含量正性相关,回归方程:Y_钙含量=-623.579+483.473X_{阿基米德骨密度}。结论:阿基米德骨密度测量方法尽管在手段上不够先进,但其可以准确描述牵张成骨过程中骨密度的变化,可以简化实验流程,降低研究费用,有利于实验研究的广泛采用。同时合并钙含量的测量,基本可以准确描述骨发生过程中骨质结构变化的过程和程度。

Study of Measurement Method of Bone Mineral Density in Distraction Osteogenesis

Objective: To study the change of bone meneral density (BMD) in distraction osteogenesis (DO), and to evaluate a new measurement method of BMD. Methods: 24 rabbits were randomly divided into 6 groups: control group and 1 day, 1 week, 2 weeks, 4 weeks, 6 weeks after DO groups. Each group included 4 rabbits. BMD was measured by Archimedes principle and by single X-ray absorptiometry (SXA), respectively. Calcium content in bone was measured by spectrometer. Results: BMD measured both by Archimedes principle and SXA and calcium content measured by spectrometer showed an increase in the distraction zone. There was no significant difference between the 6 weeks group and the control group (P>0.05). The BMD measured by Archimedes principle and by SXA had a positive correlation. The regression equation was YSXA=-0.227+0.457XArchimedes. BMD and calcium content in bone had a positive correlation. The regression equation was Ycalcium content=-623.579+483.473XBMD. Conclusions: Though the measurement method by Archimedes principle was not advanced, it could accurately monitor the change of BMD in DO, simplify the experiment process, and reduce research cost. Therefore, it could be widely used in experimental research. Combined with calcium content analysis, it can accurately monitor the changes of bone structure during osteogenesis.