Recuerda Maximilien, Coté Simon-Pierre, Villemure Isabelle, Périé Delphine
École Polytechnique, Montréal, Quebec, H3C 3A7, Canada.
J Biomech Eng. 2011 Jul;133(7):071006. doi: 10.1115/1.4004411.
The lack of standardization in experimental protocols for unconfined compression tests of intervertebral discs (IVD) tissues is a major issue in the quantification of their mechanical properties. Our hypothesis is that the experimental protocols influence the mechanical properties of both annulus fibrosus and nucleus pulposus. IVD extracted from bovine tails were tested in unconfined compression stress-relaxation experiments according to six different protocols, where for each protocol, the initial swelling of the samples and the applied preload were different. The Young's modulus was calculated from a viscoelastic model, and the permeability from a linear biphasic poroviscoelastic model. Important differences were observed in the prediction of the mechanical properties of the IVD according to the initial experimental conditions, in agreement with our hypothesis. The protocol including an initial swelling, a 5% strain preload, and a 5% strain ramp is the most relevant protocol to test the annulus fibrosus in unconfined compression, and provides a permeability of 5.0 ± 4.2e(-14)m(4)/N[middle dot]s and a Young's modulus of 7.6 ± 4.7 kPa. The protocol with semi confined swelling and a 5% strain ramp is the most relevant protocol for the nucleus pulposus and provides a permeability of 10.7 ± 3.1 e(-14)m(4)/N[middle dot]s and a Young's modulus of 6.0 ± 2.5 kPa.
椎间盘（IVD）组织无侧限压缩试验的实验方案缺乏标准化，是其力学性能量化中的一个主要问题。我们的假设是，实验方案会影响纤维环和髓核的力学性能。从牛尾提取的IVD根据六种不同方案进行无侧限压缩应力松弛实验，对于每种方案，样品的初始肿胀和施加的预载均不同。由粘弹性模型计算杨氏模量，由线性双相多孔粘弹性模型计算渗透率。根据初始实验条件，在IVD力学性能预测中观察到了重要差异，这与我们的假设一致。包括初始肿胀、5%应变预载和5%应变斜坡的方案是在无侧限压缩中测试纤维环最相关的方案，其渗透率为5.0±4.2e(-14)m(4)/N·s，杨氏模量为7.6±4.7 kPa。半侧限肿胀和5%应变斜坡的方案是测试髓核最相关的方案，其渗透率为10.7±3.1 e(-14)m(4)/N·s，杨氏模量为6.0±2.5 kPa。
