Prestige LP和Discover人工颈椎间盘的生物力学有限元分析

目的探讨人工颈椎间盘的结构设计对人工颈椎间盘置换前后生物力学变化的影响。方法基于中国可视化人研究项目的首例男性CT扫描数据图像建立人体颈椎C5-C6节段的有限元模型，使用已有文献数据验证该模型以确保计算结果准确。选用PrestigeLP和Discover分别作为不固定旋转中心和固定旋转中心结构的代表建模，在之前所建的双节段颈椎模型上模拟人工颈椎间盘置换术，对置换前后颈椎在常见运动情况下的颈椎生物力学变化进行计算和分析。结果人工椎间盘置换后，手术节段运动范围有所增大，活动度随之上升，过度运动会给后部小关节带来压力，同时导致韧带张力增加，远期可能导致脊柱失稳和手术节段退变。结论不固定旋转中心的假体运动范围大于固定旋转中心的假体，适当限制运动范围可能更有益于人工椎间盘置换后的远期疗效。

Biomechanical research of Prestige LP and Discover using finite element methods

Objective To investigate the effect of structural design of artificial disc on the biomechanical changes after disc replacement. Methods Based on clinical images, we built a three dimensional finite element model of human cervical spine, which was developed and validated by existing literature data to ensure an accurate calculation result. Then, two finite element models of Prestige LP and Discover were developed, as the representative of two different types of structural design, to simulate artificial cervical disc replacement. At last, cervical biomechanical changes in regular conditions before and after the replacement were calculated and analyzed. Results By comparing the calculated results and data from literature, we found artificial disc replacement surgery tend to increase the range of spine segment motion and excessive activity to the facet joints,which led to increased facet joint pressure and ligament tension. In the long run, artificial disc replacement surgery might lead to instability of the spine and surgical segment degeneration. Conclusions The motion range of unrestricted prosthesis is greater than that of restricted prosthesis. Appropriate limit for the range of motion maybe more beneficial to the long-term outcome after artificial disc replacement.