摘要
目的 建立正常人L3～5节段有限元模型，研究腰椎椎体间、后外侧以及环形融合方式下融合节段的稳定性，融合相邻节段椎间盘应力的变化。方法选择一名32岁正常男性，采用CT扫描，借助CATIAV5和Marc／MSC．Mentat软件，建立正常人L3～5三维非线性有限元模型。通过模拟手术失稳及在此基础上的椎体间、后外侧及环形融合，建立相应的4种有限元模型。各模型施加载荷，观察其应力分布、融合节段的角位移变化及邻近节段椎间盘的最大有效应力。结果环形融合的稳定性优于椎体间融合与横突间融合，其中以前屈与后伸加载时尤为明显。除前屈外，椎体间融合的稳定性总体优于单纯横突间融合。融合邻近节段椎间盘的最大有效应力均出现于前屈时，然后依次为侧弯、扭转、后伸。椎体间融合时邻近椎间盘的最大有效应力增加最小，横突间融合次之，环形融合时最大。结论下腰椎后路减压后行融合术时，环形融合的稳定性最好，椎体间融合的稳定性优于横突间融合。椎体间融合引起邻近节段退变的可能性最小，环形融合可能性最大，而横突间融合介于二者之间。
Objective To investigate the stability and the stress distributions of L3-5 fused with three different approaches （interbody, posterolateral and circumferential fusions） and to investigate degeneration of the segment adjacent to the fused functional spinal unit. Methods A detailed L3-5 three-dimensional nonlinear finite element model of a normal man aged 32 was established and validated. Based on the model, the destabilized model, the interbody, posterolateral and circumferential fusions models of L4-5 were established. After the loadings were placed on all the models, we recorded the angular motions of the fused segment and the Von Mises stress of the adjacent intervertebral disc. Results The circumferential fusion was most stable than the others, and the interbody fusion was more stable than the posterolateral fusion. The maximal Von Mises stress of the adjacent L3,4 intervertebral disc in all the models was ranked descendingly as flexion,lateral bending,torsion and extension. For the three kinds of fusions, the stress increment of the L3-4 intervertebral disc was ranked ascendingly as interbody fusion, posterolateral fusion and circumferential fusion. Conclusion After destabilization of the L4,5 segment, the stability of the circumferential fusion is better than that of the others, particularly under the flexional or extensional loading. The stability of the interbody fusion is better than that of the posterolateral fusion, except for under the flexional loading. The feasibility of adjacent segment degeneration can be ranked descendingly as： circumferential fusion,posterolateral fusion and interbody fusion.
出处
《中国修复重建外科杂志》
CAS
CSCD
北大核心
2006年第4期400-403,共4页
Chinese Journal of Reparative and Reconstructive Surgery
关键词
腰椎
脊柱融合
生物力学
有限元法
Lumbar spine Spinal fusion Biomechanics Finite element analysis
