羊胫骨干骺端截骨延长术后外固定时间的实验研究

The optimal Period of External Fixation af-ter Tibial Lengthening by Metaphyseal Osteoto- my:An Experimental Study in Goats

本研究采用羊胫骨上干骺端截骨延长动物模型以确定羊干骺端截骨延长术后外固定的最佳时间。Ｘ线片、组织学、骨矿含量测定及生物力学技术被用来评定延长区骨组织的修复情况。实验结果表明：治疗后期，外固定架将产生不利于新生骨组织改建和再塑的应力保护作用。在本模型中，当延长率为１５％时，去除外固定的最佳时间是停止延长后第８～１０周，即当延长区骨强度和刚度分别达到对照组的５０％和１００％时。

AbstractTibial lengthening by upper tibial metaphyseal os-teotomy was done in goats, in order to determine the opti-mal time for the removal of the external fixation after surgery. Roent8enography, histology, bone mineral content detetmination and biomechanical technique were used to estimate the extent of bone healing.The results showed that in the later peried of the treatinent,external flxatormay cause stress shielding effect,which is unfavorable forthe reconstr uctioi1 and rernedetu1g of the regeneratedbne. In the goat model,when the elongation reached15%,the optimal time for external flxator removal is be-tween 8-1 0 weeks after cessation of lengthening,i,e. when the strength and the stiffness of the lengthened bonehave reached respectively 50%and 1 00%of that of thecontrol group.