轴向加载对腰椎结核模型稳定性影响的三维有限元研究

Axial Load Effect on the Stability of Lumbar Spinal Tuberculosis in a Three-dimensional Finite Element Model

目的:研究轴向加载对腰椎结核三维有限元模型稳定性的影响,为临床治疗腰椎结核提供生物力学理论依据。方法:选取自愿者采集CT数据,采用专用生物力学软件建立正常材质的L2～L5节段腰椎模型和5种不同的结核模型,在相同的轴向加载条件下进行分析。结果:通过轴向加载发现,正常腰椎的平均刚度为277N/mm,A、B、C、D、E五型结核腰椎的平均压缩刚度分别为233N/mm、239N/mm、275N/mm、253N/mm和217N/mm。腰椎结核模型平均刚度比正常模型最大减小近22%;在应力方面,结核破坏区域位于骨皮质时影响最大,出现大的应力集中情况;同时,结核破坏对于椎间盘的力学传导有很大影响。结论:腰椎结核破坏影响腰椎的稳定性,不同部位的结核破坏产生相应的应力集中,研究结果对临床治疗有指导意义。

Objective：To study the influence of axial load on lumbar spine tuberculosis stability with a three-dimen-sional finite element model, and to provide the necessary biomechanical theoretical basis for the treatment of spinal tuberculosis. Methods：A normal material FE model of L2~L5 Lumbar model and 5 different types of tuberculosis models were generated by using specially designed modeling system after CT data collected from a volunteer sub-ject and then the same axial loading conditions were applied to do comparison. Results：After axial loading,lumbar tuberculosis stability was affected by tuberculosis：the average stiffness of A,B,C,D,and E lumbar spinal tuberculo-sis models were 233,239,275,253,and 217 N/mm,with a 22% reduction at most when compared to 277 N/mm of the normal model. For stress result, tuberculosis located in the cortical bone brought serious impact, with large stress concentration. Tuberculosis also seriously influenced the mechanical conduction of the intervertebral disc. Conclusion：Tuberculosis can affect lumbar stability;different locations of tuberculosis produces the corresponding stress concentration. These findings may have guiding significance on the clinical diagnosis.