Prestige^(TM)-LP颈椎人工椎间盘置换后椎体应力及关节突关节间压力有限元分析

Finite Element Analysis on Vertebral Stress Distributions And Pressure Variations of Facet Joint Following Prestige^(TM)-LP Artificial Disc Replacement

目的:分析PrestigeTM-LP颈椎人工椎间盘对椎体的应力和关节间压力作用,了解节段间运动载荷传递方式及作用机制。方法:通过实体CT扫描方式建立颈4~5节段PrestigeTM-LP人工椎间盘置换有限元模型。生理载荷下前屈、后伸、左侧弯、左轴向旋转时测量颈5椎体应力和颈4-5关节突间压力变化。结果:运动加载后C5椎体应力均有不同程度增大,表现出与运动加载方向一致的应力偏移改变。相比于前屈,后伸时双侧关节突间压力明显增大。左侧弯时左侧关节突间压力增大,左轴向旋转时右侧关节突间压力明显增大。结论:采用有限元模型进行骨性结构的应力及压力分析具有形象及精确的优点。PrestigeTM-LP颈椎人工椎间盘置换有效地起到椎体间应力传递和保留关节突关节间压力作用,具有接近正常颈椎的生物力学特性。

Objetcive： To analyse on vertebral stress distributions and pressure variations of facet joint. To better understand the load transfer pattern and mechanical effect following artificial disc replacement. Methods： The FEM of C4-C5 following Prestige^TM-LP artificial disc replacement was established by transferring the CT date to finite element modeling software. Analysis on C5 vertebral stress and C4-C5 facet joint pressure were conducted under normal physiologic loads in flexion, extension, left lateral bending and left axial rotation. Results： Motion loads induces C5 vertebral stress increase and stress distributions present displacement conformed with motion direction. Facet joint pressure increases obviously on extension more than flexion. Left facet joint pressure increases obviously on left lateral bending and right facet joint pressure increases obviously on left axial rotation respectively. Conclusions： The FEM possesses a high precision and visual image on stress analysis of skelecton structure. Prestige^TM-LP artificial disc prosthesis well preserves intervertebral stress transfer and contact pressures in facet joint, possesses biomechanical character near normal cervical spine.