Silva P, Crozier S, Veidt M, Pearcy M J
Department of Mechanical Engineering, University of Queensland, Brisbane, Australia.
J Mater Sci Mater Med. 2005 Jul;16(7):663-9. doi: 10.1007/s10856-005-2538-0.
A hydrogel intervertebral disc (IVD) model consisting of an inner nucleus core and an outer anulus ring was manufactured from 30 and 35% by weight Poly(vinyl alcohol) hydrogel (PVA-H) concentrations and subjected to axial compression in between saturated porous endplates at 200 N for 11 h, 30 min. Repeat experiments (n=4) on different samples (N=2) show good reproducibility of fluid loss and axial deformation. An axisymmetric nonlinear poroelastic finite element model with variable permeability was developed using commercial finite element software to compare axial deformation and predicted fluid loss with experimental data. The FE predictions indicate differential fluid loss similar to that of biological IVDs, with the nucleus losing more water than the anulus, and there is overall good agreement between experimental and finite element predicted fluid loss. The stress distribution pattern indicates important similarities with the biological IVD that includes stress transference from the nucleus to the anulus upon sustained loading and renders it suitable as a model that can be used in future studies to better understand the role of fluid and stress in biological IVDs.
一种由内部髓核和外部纤维环组成的水凝胶椎间盘(IVD)模型,是由重量浓度为30%和35%的聚乙烯醇水凝胶(PVA-H)制成的,并在饱和多孔终板之间以200 N的力进行轴向压缩11小时30分钟。对不同样本(N = 2)进行重复实验(n = 4),结果表明液体流失和轴向变形具有良好的可重复性。使用商业有限元软件建立了一个具有可变渗透率的轴对称非线性多孔弹性有限元模型,以将轴向变形和预测的液体流失与实验数据进行比较。有限元预测表明,液体流失差异与生物椎间盘相似,髓核比纤维环流失更多的水分,并且实验和有限元预测的液体流失总体上具有良好的一致性。应力分布模式表明与生物椎间盘有重要相似之处,包括持续加载时应力从髓核转移到纤维环,使其适合作为一个模型,可用于未来的研究,以更好地理解液体和应力在生物椎间盘中的作用。