中文摘要：

目的通过对比钉棒系统和钢板内固定Tile B2型骨盆骨折的生物力学行为,研究钉棒系统固定骨盆骨折的有效性。方法构建包含韧带结构的正常骨盆和2钉、3钉患侧、3钉健侧、钢板内固定Tile B2型骨盆有限元模型,在S1椎体上施加500 N均布载荷,模拟骨盆在双腿站立、单腿站立和坐位下的受力情况,对比正常骨盆与钉棒内固定、钢板内固定骨盆的位移和应力分布。结果钉棒系统和钢板均能对骨盆骨折进行有效固定,两者显示出与正常骨盆相似的位移和应力分布。各内固定中,3钉患侧内固定骨盆的最大位移在各工况下均最小,同时其应力水平明显低于其他内固定,双腿站立下其最大等效应力比2钉、3钉健侧和钢板内固定分别降低30.4%、20.8%、20.3%;坐位下分别降低31.8%、25.4%、18.5%;单腿站立下分别降低-6.5%、28.0%、61.1%。结论钉棒系统能够对Tile B2型骨盆骨折进行有效固定,且3钉患侧固定效果最佳。研究结果能够为临床骨盆骨折的方案选择提供理论依据。

英文摘要：

Objective To investigate the validity of screw-rod system for fixing pelvic fractures by comparing the biomechanical behaviors from using screw-rod system or steel plate for fixing Tile B2 type pelvic fractures. Methods The finite element models of normal pelvis including ligaments,and Tile B2 fractured pelvis fixed by different screw-rod fixations（ 2 screws at fractured side,3 screws at fractured side and at healthy side）,and steel plate fixation were established. The vertical load（ 500 N） was applied on the upper terminal plate of the first body of the sacrum to simulate pelvis load during double-leg standing,single-leg standing and sitting. The displacement and stress distributions on normal pelvis and fractured pelvis with screw-rod fixation or with steel plate fixation were compared and analyzed. Results Both the screw-rod system and steel plate could effectively fix the fractured pelvis,and the fixation models showed similar displacement and stress distribution as normal pelvis. The largest displacement of fractured pelvis with 3-screw fixation on the diseased side was smallest under each working condition,and its stress level was also obviously lower than that of the other internal fixation models. During double-leg standing,compared with 2 screws fixation,3 screws at healthy side fixation,and steel plate fixation,the Von Mises stress for 3 screws at fractured side fixation was reduced by 30. 4%,20. 8%,20. 3%; during single-leg standing,the Von Mises stress for 3 screws at fractured side fixation was reduced by 31. 8%,25. 4%,18. 5%; during sitting,the Von Mises stress for 3 screws at fractured side fixation is reduced by- 6. 5%,28. 0%,61. 1%,respectively. Conclusions The screw-rod system can fix Tile B2 pelvic fracture effectively,especially for3-screw fixation on the fractured side. The results can provide the theory basis for clinical treatment of pelvic fracture.