Malandrino Andrea, Noailly Jérôme, Lacroix Damien
a Institute for Bioengineering of Catalonia , Barcelona , Spain.
Comput Methods Biomech Biomed Engin. 2013;16(9):923-8. doi: 10.1080/10255842.2011.644539. Epub 2012 Jan 6.
The collagen network of the annulus fibrosus largely controls the functional biomechanics of the lumbar intervertebral discs (IVDs). Quantitative anatomical examinations have shown bundle orientation patterns, possibly coming from regional adaptations of the annulus mechanics. This study aimed to show that the regional differences in annulus mechanical behaviour could be reproduced by considering only fibre orientation changes. Using the finite element method, a lumbar annulus was modelled as a poro-hyperelastic material in which fibres were represented by a direction-dependent strain energy density term. Fibre orientations were calibrated to reproduce the annulus tensile behaviours measured for four different regions: posterior outer, anterior outer, posterior inner and anterior inner. The back-calculated fibre angles and regional patterns as well as the global disc behaviour were comparable with anatomical descriptions reported in the literature. It was concluded that annulus fibre variations might be an effective tool to calibrate lumbar spine IVD and segment models.
纤维环的胶原网络在很大程度上控制着腰椎间盘(IVD)的功能生物力学。定量解剖学检查已经显示出束状排列模式,这可能源于纤维环力学的区域适应性。本研究旨在表明,仅考虑纤维方向变化就可以再现纤维环力学行为的区域差异。使用有限元方法,将腰椎纤维环建模为一种多孔超弹性材料,其中纤维由一个与方向相关的应变能密度项表示。校准纤维方向以再现四个不同区域(后外侧、前外侧、后内侧和前内侧)测量的纤维环拉伸行为。反算得到的纤维角度和区域模式以及整体椎间盘行为与文献中报道的解剖学描述具有可比性。得出的结论是,纤维环纤维变化可能是校准腰椎IVD和节段模型的有效工具。