TLIF单双侧椎弓根螺钉固定融合前后的有限元分析  

Finite element analysis of unilateral and bilateral pedicle screw fixation before and after segment fusion in transforaminal lumbar interbody fusion

作　　者：刘玉武[1] 李杰[2] 周跃[2] 

机构地区：[1]浙江省江山市人民医院骨科,浙江江山324100 [2]第三军医大学新桥医院骨科,重庆400037

出　　处：《重庆医学》2015年第12期1599-1602,共4页Chongqing medicine

基　　金：国家科技部科技支撑计划资助项目(2012BAI14B02);重庆市科委重大专项资助项目(CSTC2012ggyyjsB10012)

摘　　要：目的探索经椎问孔腰椎椎间融合术（TLIF）单双侧椎弓根螺钉固定方式在椎间植骨融合前后存在的差异。方法基于正常人L3～。节段的CT扫描数据建立人正常k3-5三维有限元模型（INT）和TLIF手术模型，并在此基础上构建椎间融合前单侧和双侧椎弓根螺钉固定模型（M1和M2），以及椎间融合后单侧和双侧椎弓根螺钉固定模型（M3和M4）。在设定的加载和边界条件下，模拟腰椎前屈、后伸、侧屈及旋转运动，并记录L4-5节段角位移和内植物应力分布情况。结果单侧和双侧椎弓根螺钉固定模型在融合前均较完整状态减少了节段的活动度，双侧固定减少幅度更大，而融合后这种差异明显缩小。融合前单侧固定的钉棒系统VonMises应力峰值明显高于双侧固定，而融合之后二者应力峰值趋于一致。结论融合后单侧固定可以提供和双侧固定一致的节段稳定性，TLIF手术应用单侧椎弓根螺钉固定的远期临床效果与双侧固定相似。Objective To explore the difference between before and after intervertebral fusion in transforaminal lumbar inter- body fusion （TLIF） by unilateral or bilateral pedicle screw （PS） fixation. Methods The L3-5CT data based on the normal people were used to rebuild the L3-5 three-dimensional finite element model（INT） and TLIF operative model. On this basis,the unilateral PS fixation （M1） and bilateral PS fixation （M2） models before the intervertebral fusion and the unilateral PS fixation （M3） and bi- lateral PS fixation （M4） models after intervertebral fusion were built. After setting the boundary and loading the burden,the ante- flexion, retroversion,lateral bending and rotation of lumbar vertebra were simulated and the L4-5 segment angular displacement and the stress distribution of implant were recorded. Results The unilateral and bilateral PS fixation model before fusion reduced the range of motion（ROM） of segment compared with the INT model, the bilateral fixation was reduced greater than the unilateral fixa- tion, but the difference after fusion was significantly decreased. The peak Yon Mises stresses before fusion in the unilateral PS fixa- tion was significantly higher than that in the bilateral fixation,while their peak Von Mises stresses after fusion trended to be con- sistent. Conclusion The unilateral PS fixation after fusion can provide the consistent segment stability same to the bilateral PS fixa- tion. The long-term effect of TLIF with unilateral PS fixation is similar to that with the bilateral PS fixation.

关 键 词：经椎间孔腰椎椎间融合术 椎弓根螺钉固定 有限元分析 

分 类 号：R687.3[医药卫生—骨科学]