骨外固定的应力遮挡作用与骨质疏松关系的实验研究

目的 探索骨外固定的应力遮挡作用与骨质疏松的关系。方法 取30条成年狗于左侧胫骨用简易单边式外固定支架固定，固定后2，4，8，12周处死取材。通过组织学，超微结构，CT扫描及生物力学方法测定和分析。结果 外固定2－4周，固定段无明显变化，8－12周固定段发生骨质疏松。结论 骨外固定的应力遮挡作用较小，因此早期会促进骨的愈合。但如果长期固定则会造成骨质疏松，不利于骨的愈合。

Relationship between stress shelter effect of the external fixation and osteoporosis

Objective To study the relationship between stress shelter effect of the external fixation and osteoporosis.Methods Thirty grow-up dogs were used in the experiment. The left tibia of the animals were fixed with a simple unilateral external fixation apparatus. Six or seven dogs each were executed at 2,4,8 and 12 weeks after operations. The observation methods included light microscopy, transmission electron microscopy, CT scanning and biomechanical test. Results There was no significant difference between fixed segment and control sides after 2 to 4 weeks of external fixation, but regional osteoporosis of fixed segment were found after 8 to 12 weeks of external fixation. Conclusion The stress shelter effect of the external fixation is weak, so it is helpful for bony union in the early time, but it will cause osteoporosis to fix for a long time, and it is bad for bony union.