双能X射线骨密度仪测量离体羊股骨骨折端及钢板对接骨折端的骨密度

Ex vivo femoral bone mineral measurements in sheep using dual energy X-ray absorptiometry

背景:目前,羊已逐渐成为骨质疏松研究中很有前途的动物模型。目的:采用双能X射线骨密度仪测量羊股部骨折断端及全部骨密度,探讨双能X射线骨密度仪测量过程中的准确度和精确度。方法:对双能X射线骨密度仪自带的Lunar腰椎模型扫描10次/d,确定机器准确度,再连续扫描25d,根据所测数据建立Shewhart控制图。选取3只羊中5根股骨进行7次重复扫描,采用骨密度仪自带的小动物分析软件分析羊股部骨折断端的骨密度、全部的骨密度,计算其精密度。另外选取4只羊8根股骨,用2种钢板对骨折断端固定,分析骨密度及骨矿含量的变化。结果与结论:双能X线骨密度仪的准确度为-1.0%,离体羊股部骨折断端及全部的骨密度测量精密度为0.005～0.537g/cm2。股骨全部骨和骨折断端密度的短期精密度分别为0.8%和1.5%,股骨全部和骨折断端骨矿物含量的短期精密度为0.9%和7.5%。不同钢板固定后的羊股骨骨密度、骨矿含量差异无显著性意义。结果证实,双能X射线骨密度仪能准确测量离体羊股骨的骨密度,但在骨折断端骨矿含量精密度分析有一定的误差。

BACKGROUND：At present,sheep has gradually become a promising model in osteoporosis research.OBJECTIVE：To measure the sheep femoral fracture fragments and all bone mineral density by the dual energy X-ray absorptiometry（DXA）,and to discusses the precision and accuracy of the DXA in the process of measurements.METHODS：The Own Lunar lumbar model was scanned with DXA 10 times every day in order to determine the precision of the machine and then continuous scanned for 25 days.Shewhart control chart was established according to the measured data.Five femoral bones were selected from three sheep and scanned repeatedly seven times.The DXA animal analysis software was used to analyze the bone density of the sheep femoral fracture fragments and all bone mineral density to calculate its accuracy.Besides,eight femoral bones from four sheep were selected,fixed at the femoral fracture site by two kinds of steel plates for analysis of bone mineral density and observation of bone mineral content changes.RESULTS AND CONCLUSION：The precision of the machine was-1.0% and the accuracy of the sheep femoral fracture fragments and all bone density was 0.005-0.537 g/cm2.The short-term precisions of the femoral and fracture fragments bone mineral density were separately 0.8% and 1.5%,and the short-term precisions of the femoral and fracture fragments bone mineral content were 0.9% and 7.5%.There was no significant meaning in the bone density of sheep femoral fixed by different plates and bone mineral content difference.The results confirm that the DXA can accurately measure the bone density of the femur in vitro,but there are some errors in analyzing the bone mineral density of fracture fragments.