颈椎人工间盘植入与融合固定后生物力学有限元比较分析

Finite element analysis on biomechanics of cervical spondylosis treated with artificial cervical disc replacement vs.anterior cervical decompression and fusion

目的研究颈椎人工间盘植入与前路融合内固定术后颈椎邻近节段的活动度、椎体及椎间盘内应力改变等生物力学分布的差异。方法选取湖北医药学院附属东风医院脊柱外科采用两种手术方法治疗的单节段颈椎病患者,采用螺旋CT扫描分别获取在前屈、后伸、侧屈及旋转几种状态下的颈椎椎体、椎间盘、韧带断层图像,在Mimics软件中重建三维结构,然后导入Ansys10.0软件分别建立有限元模型。并求解计算,分析术后患者的颈椎结构变化及椎体终板接口的位移变化和应力分布,比较研究载荷传导、生物力学分布及稳定性情况的差别。结果人工颈椎椎间盘置换术后患者的邻近节段活动基本正常,融合术后患者邻近节段的活动丧失达65%~75%。人工颈椎间盘置换术后患者邻近节段椎体及椎间盘内应力变化较小,融合术后患者在受到压力时,邻近椎间盘内应力增加明显,内植物与终板接口处应力集中。结论人工颈椎间盘置换对邻近节段的生物力学影响很小,并不影响颈椎的正常活动。

Objective To explore the difference in biomechanicaI effects of artificial cervical disc replacement vs. anterior cervical decompression and fusion. Methods CT scans were performed on the patients who respec- tively underwent the two operations in the Spine Surgery of Dongfeng Hospital of Hubei University of Medicine. After these images were processed, the three dimensional finite element model was established by software Mimics and Ansysl0. {I in order. After the loadings were placed on all the models, the difference in biomechanical and the distribution of Von Mises stress of the fused segment were analyzed and compared. Results The artificial cervical disc replacement allowed to correctly reproduce a physiological motion at the implanted level. The fusion reduced the mobility at its level by about 65^-75Y00 for the considered loading cases. Moreover, the fusion resulted in a higher increase in the ad）acent discs in compression, on the contrary, the prosthesis produced little changes in adja- cent segments. The artificial cervical disc prosthesis well restored the biomechanical behavior of the intact spine and produced little effect on the adjacent segments. Conclusion The artificial cervical disc prosthesis well restores the biomechanical behavior of the intact spine and produces little effect on the adjacent segments.