颈椎人工椎间盘置换有限元分析

目的　建立C4~5节段PrestigeTM-LP颈椎人工椎间盘植入后的三维有限元模型，进行手术节段的运动分析。 方法 采用对成年男性的新鲜尸体的颈椎标本进行CT三维扫描方法建立C4~5节段和PrestigeTM-LP人工间盘有限元，模拟完成C4~5人工椎间盘置换手术。测量生理加载下手术节段前屈/后伸、侧弯及轴向旋转运动角度。结果 有限元模型对颈椎的结构，包括椎体间韧带、颈椎关节突关节、钩椎关节等均进行了精确的重建，并较好地模拟手术操作进行PrestigeTM-LP人工间盘植入。运动加载后运动角度，前屈5.7°，后伸3.5°，侧弯5.0°，旋转11.3°，与文献报道结果较为接近。 结论　有限元模型具有精确度高，手术模拟真实的特点，可作为颈椎人工椎间盘生物力学研究的一种较好途径。PrestigeTM-LP颈椎人工椎间盘置换可较好地保留手术节段的运动功能。

Finite element analysis of cervical spine following artificial intervertebral disc replacement

Objective　To establish a three-dimensional finite element model of cervical spine C4～5 segment following PrestigeTM-LP artificial intervertebral disc replacement and analyze segmental motions. Methods　The geometry of C4～5 vertebrae was reconstructed from computer tomography (CT) scan images of an adult male human fresh cervical spinal specimen. A FEM of C4~5 vertebrae and PrestigeTM-LP prosthesis was established and simulated clinical operation by using ANSYS10.0 system. Motions of flexion, extension, lateral bending and axial rotation were determined in physiological loading.　Results　Detailed geometries of vertebral bodies were modeled including ligaments, facet joints, and uncovertebral joints. Motions of flexion, extension, lateral bending, axial rotation are 5.7°, 3.5°, 5.0°,11.3°，respectively and conform with what have been reported in the literature.　Conclusions　The FEM possesses a high precision of geometries of vertebral bodies and biomechanical character. PrestigeTM-LP artificial disc prosthesis well preserves intervertebral segmental motion for cervical spine.