双能X线骨密度仪测定骨痂骨密度变化的实验研究

目的: 研究骨折愈合过程中骨密度的动态变化,判断双能X线骨密度仪评估骨痂骨密度的可行性.材料和方法:30只犬造成右胫骨中段骨折并分断端距离4mm,单边外固定支架固定.分别在术后4、6、8、10、12周取双侧胫骨,以双能X线骨密度仪测定骨折端1cm的骨密度,分析骨密度变化及骨密度增长率的变化.结果:骨折端骨密度随时间呈一定规律增加,在不同时间组间差异有显著意义(P<0.01).自身对照的骨密度比率也随时间增加,在各组间差异有显著意义(P<0.01).12周时骨折端骨密度达到正常侧水平.结论:在犬骨折愈合过程中骨痂骨密度持续增加,双能X线骨密度仪可用于骨愈合中骨痂的骨密度判断.

Experimental Study on Bone Mineral Density Changes of Callus During Fracture Healing

Purpose: To explore the callus bone mineral density changes during fracture healing and evaluate the feasibility of quantitative assessment of callus bone mineral density with dual energy X ray absorptiometry (DEXA). Materials and Methods: In 30 beagles, a right midshaft tibial osteotomy was performed and was stabilized with a 4 mm gap using an external fixator. A group of 5 animals was euthanized at 4,6,8,10,12 weeks respectively after surgery. Both tibias were harvested and bone mineral density was measured in a 1cm region using DEXA. One way ANOVA (analysis of variance)was performed to analyze the difference of callus bone mineral density and bone mineral density ratio between groups. Results: callus bone mineral density increased over time. There was a significant difference of callus bone mineral density and bone mineral density ratio between groups (P<0.01). Conclusion: Callus bone mineral density increased continuously in normal beagle fracture healing models. DEXA could be used to assess the callus bone mineral density during fracture healing.