不同位置植入SMH人工腰椎间盘对小关节应力分布的影响

目的:通过三维有限元方法研究正常椎间盘、SMH人工腰椎间盘前置、中置和后置四组模型中小关节的应力分布情况,探讨不同位置植入SMH人工腰椎间盘对小关节应力分布的影响。方法:建立正常腰椎间盘、人工SMH腰椎间盘前置、中置和后置的三维模型,然后模拟腰椎节段的运动,进行小关节应力分布的比较研究。结果:与正常L4/5椎间盘模型相比,除SMH人工腰椎间盘前置模型前屈时比正常模型小关节应力小外,其余运动时SMH人工腰椎间盘前置、中置和后置模型中小关节的应力均高于正常腰椎间盘组,但后置SMH人工腰椎间盘组则相对较小。结论:SMH人工腰椎间盘后置可以更好地预防小关节的退变;人工椎间盘植入位置的不同对人工腰椎间盘术远期疗效的预测具一定的作用。

The effects on facet joint stress distribution following insertion of SMH artificial lumbar intervertebral disc in different position

Objectives: To study facet joint stress distribution in the models of normal disc and SMH artificial disc with anterior, middle or posterior positions respectively by 3-D finite element method and explore the effects of SMH artificial disc on stress distribution of facet joints. Methods: FE models was built on normal disc, SMH artificial disc with anterior, middle and posterior location by finite element software, and then facet joint stress was analyzed through the model of the L4/5 motion segment respectively. Results: Compared to that of normal disc, the facet joint stress of SMH artificial disc with anterior, middle or posterior location was larger in any state except in anteflexion location. Among 3 groups of artificial disc, posterior location group had the smallest facet joint stress. Conclusions: Posterior location of SMH artificial disc is the best for precluding the degeneration of facet joints. The long-time effect of artificial disc replacement can be predicted through the location of them.