限制型颈前路内固定钢板的有限元模拟及其生物力学分析

Biomechanical evaluation and finite element analysis of the restricted anterior cervical spine plate

目的评估颈前路内固定钢板在轴向压力、前屈、侧弯和扭转等四种生理性工况下的生物力学特性及其应力/应变分布,为临床上对颈前路内固定钢板的选择及其设计提供科学的参考依据。方法在国人颈椎解剖结构统计学数据和颈前路内固定钢板尺寸数据的基础上,建立颈椎C5-C6功能节段-限制型颈前路内固定钢板的有限元模型,计算其在人体生理性工况下的应力/应变分布。结果在生理性载荷下,应力/应变集中分布在骨螺钉和内植入固定板的结合部位以及内固定板的中心位置,边缘处应力/应变较小。结论在轴向压力、前屈、侧弯和扭转四种生理性载荷下,应力/应变集中分布在颈前路内固定钢板和骨螺钉的结合处,又因该结合处为螺钉结构连接,所以,此结合处刚性连接比较薄弱,易发生内固定失败。

Objective We evaluated the biomecbanical property and stress/strain distribution of restricted anterior cervical plate（ACP） under the physiologic compression, flexion, lateral bending and torsion conditions,in order to choose and design the ACP well in clinical cases. Method Based on the statistic data of Chinese cervical spines and restricted ACP, the finite element model of restricted ACP＆C5-C6 functional vertebral segment was created and then the distribution of stress/strain was obtained by the model. Result Under the the four physiological loadings, the stress/strain mainly distributes on the connection part between bone screw and ACP, and on the centre of ACP, the stress/strain on the edge of plate is less. Conclusion The stress/strain mainly distributes on the connection between bone screw and restricted ACP, where is screw structure one . Therefore, this place is much weaker for rigid structure and easy to cause the failure of internal fixation.