微动对骨折端骨密度的影响

目的:研究骨折端微动时应力对骨密度的影响。方法:60只新西兰大白兔随机分为微动组与固定组,每组30只。固定组术后使骨折端固定。微动组使外固定架中间杆有0.5mm的轴向移动,术后动物自由行走,依靠体重使外固定架产生微动。利用双能X线骨密度测量仪测定两组动物骨痂的骨密度。结果:术后14d时固定组、微动组骨密度为正常的10%左右,两组无显著差异。21、28d两组骨密度有明显上升,微动组与固定组比较差异有显著性意义(P<0.01)。42d时微动组骨密度高于正常水平。56d时微动组骨密度稍下降,但仍高于正常,固定组骨密度高于正常水平,两组无显著差异(P>0.05)。结论:微动可增强骨愈合时骨痂的骨密度。

Effects of micromovement on the bone mineral density of the broken end of bone fractures

Objective:To study the influence of micromovement on the bone mineral density of the broken end of bone fractures.Methods:Sixty rabbits were randomly divided into micromovement group and fixation group.There were 30 rabbits in each group.After operation,the broken ends of rabbits in fixation group were fixed.In micromovement group,0.5 mm space was left on middle rod of the external fixator,the broken ends of fractures of the rabbits could move axilely depending on their body weight.The bone mineral density (BMD) was measured with dual-energy X-ray absorptionmetry.Results:At the 14th day after operation,the BMD of the micromovement group and the fixation group was just 10% of the normal level,there was no significantl difference between the two groups(P<0.05).The BMD of the two groups increased greatly at the 21th and 28th days.the BMD of the micromovement group was higher than that of fixation group (P<0.01).At the 42 day,the BMD of micromovement group was higher than the mormal level.At the 56th day,the BMD of the two groups were both higher than the normal level,but there was no significant difference between the micromovement group and the fixation group (P>0.05).Conclusion:Micromovement could in crease the bone mineral density.