腰4、5侧路单枚椎间融合器融合术式的生物力学研究

Biomechanical evaluation of L_4,L_5 interbody fusion with single lateral threaded cage insertion

目的评价侧路单枚椎间融合器融合术式的稳定性及力学合理性。方法建立L4、L5侧路与后路单枚椎间融合器融合术式的三维有限元模型及小牛脊柱模型,测定二者于各种载荷时有关节点的位移,并行统计学分析。结果三维有限元模型分析显示,于腰椎屈曲、后伸、右侧弯及旋转等功况下侧路单枚椎间融合器模型的稳定性均较后路单枚椎间融合器模型高(P<0.05)。小牛脊柱模型力学测试也显示,于腰椎屈曲、后伸、左右侧弯及旋转等功况下侧路单枚椎间融合器模型的刚度均较后路单枚椎间融合器模型高(P<0.001)。结论侧路植入单枚椎间融合器融合术式不使用椎弓根内固定系统而又能够提供足够的术后即刻稳定性,从生物力学角度看,该术式比后路术式更具优势,为一种合理有效的腰椎椎体间融合术式。

Objective To investigate the biomechanical and the rationality of mechanics stability of intervertebral fusion through lateral approach .Methods Three‐dimension finite element models and calf lumbamodels of L4 ,L5 intervertebral fusion with one TFC inserted by lateral approach and with one TFC inserted by posterolateral approach were established .Nondestruc‐tive tests were performed .The values were analyzed with SSPS software . Results The analysis of three‐dimension finite ele‐ment model showed that the model had a significantly higher stability than model in the way of escape in extension ,flexion ,right lateral bending and rotation ,especially in rotation load （P〈0.05） .The test of calf spine model group showed that the model in sideway had a significantly higher stiffness than the model in the way of escape in flexion ,extension ,right and left lateral ben‐ding （P〈0.001） .Conclusion Intervertebral fusion with TFC insertion laterally enables sufficient decompression while it main‐taints a majority of the posterior element of spine ,and ensures better fusion condition .The operation method can take place of intervertebral fusion with TFC insertion posterolaterally .