颈椎终板生物力学特性在前路融合术中的作用

目的研究颈椎保留终板与去除终板状态下不同位点生物力学特性的分布规律,评价颈椎终板在前路融合术中的作用。方法将骨密度无差异的42例人体新鲜颈椎标本随机分为两组(保留终板组24例,去除终板组18例),对每一终板平面上22个特定的测试点进行压缩实验,直径2mm的半球形压头以0.03mm/s的速度垂直于终板平面下压2mm,由所得的力-位移曲线计算出最大压缩力及刚度,采用t检验、析因分析及SNK检验对实验数据进行统计学分析。结果颈椎上、下终板保留终板组与去除终板组之间的最大压缩力及刚度的比较均有显著性差异。颈椎后部是保留终板组颈椎上终板力学强度较大的区域,颈椎外侧区是颈椎下终板力学强度较大的区域;去除终板组颈椎后部是上终板平面力学强度较大的区域,颈椎后外侧是下终板平面力学强度较大的区域。结论颈椎终板在颈椎前路融合术中起着相当重要的作用,在进行手术或改进椎间植入物设计时应考虑到此作用。

Role of the biomechanical property of the endplate in anterior cervical fusion

Objectives To study the distribution of the biomechanica l properties in the cervical vertebrae with or without the endplate, so as to eva luate the importance of the endplate in cervical anterior fusion. Methods Indent ation tests were performed at 20 standardized testing points chosen on each sur face of the endplate with the impact adjusted perpendicular to the endplate sur face using a hemispherical indenter 2 mm in diameter. The failure load and rigid ity at each test site were determined from the load-displacement curves. Indepe ndent sample t test and factorial analyses were used to analyze the results. Res ults On either superior or inferior endplate surface, both the failure load and rigidity differed significantly between the endplate-intact and endplate-remov ed groups (P<0.001). The posterior region of the superior endplate and the later al regions of the inferior endplate were stronger and more rigid than any other region across the endplate surface in the endplate-intact group, while for enp late-removed group, the posterior region of the superior endplate and the poster olateral regions of the inferior endplate were the stronger and more rigid. Con clusions The endplate plays an important role in deciding the success of anterio r cervical fusion, and due attention should be paid to the endplate in the inte rvertebral implant device designing and the surgical approach modification.