弯曲工况下钉数和钉的分布对胫骨骨折外固定稳定性的影响

目的揭示不同钉分布和钉数对胫骨-外固定器稳定性的影响.方法以人干燥的尸体胫骨中部行单侧外固定器固定为实验模型.通过电测法观测不同加压量固定的不同实验模型在不同等级弯曲工况下骨表面的应变及轴向位移变化;并设定节点和单元后对胫骨-外固定器系统进行计算应力分析.结果在弯曲工况下,4钉均匀分布及6钉均匀分布的稳定性较强,但后者稳定性更佳.结论应用单侧外固定器治疗胫骨骨折时,应采用4钉均匀分布,条件许可时采用6钉均匀分布.

An effect of fixators stability of different distributions and number of screws for tibial fracture under torsion condition

Objectives To explore an effect of the stability of the system of tibia-external fixation from different distributions and numbers of screws Methods Experimental models were decided when human corpse tibial transverse fractures fixated with unilateral external fixations. The method of electric resistance fragments were used to observed values of stress of bone surface and axial displacement at grade loads and various models. And the stress of tibia-external fixation was analyzed. Results Under bending condition, the stability was better when screws distributions were even at four or six screws compared to other models,but the latter stability was excellent. Conclusion The even distribution of four screws was reasonable when tibial fractures were treated with unilateral external fixation,and six screws might be chosen if conditions were permitted.