Heo Minhyeok, Park Seonghun
School of Mechanical Engineering, Pusan National University, Busan 46241, Korea.
Materials (Basel). 2022 Jan 31;15(3):1125. doi: 10.3390/ma15031125.
PVAH is a mixture of solid and fluid, but its mechanical behavior has usually been described using solid material models. The purpose of this study was to obtain material properties that can reflect the mechanical behavior of polyvinyl alcohol hydrogel (PVAH) using finite element analysis, a biphasic continuum model, and to optimize the composition ratio of PVAH to replace the nucleus pulposus (NP) of the human intervertebral disc. Six types of PVAH specimens (3, 5, 7, 10, 15, 20 wt%) were prepared, then unconfined compression experiments were performed to acquire their material properties using the Holmes-Mow biphasic model. With an increasing weight percentage of PVA in PVAH, the Young's modulus increased while the permeability parameter decreased. The Young's modulus and permeability parameter were similar to those of the NP at 15 wt% and 20 wt%. The range of motion, facet joint force, and NP pressures measured from dynamic motional analysis of the lumbar segments with the NP model also exhibited similar values to those with 15~20 wt% PVAH models. Considering the structural stability and pain of the lumbar segments, it appears that 20 wt% PVAH is most suitable for replacing the NP.
聚乙烯醇水凝胶（PVAH）是固体和流体的混合物，但其力学行为通常使用固体材料模型来描述。本研究的目的是通过有限元分析、双相连续介质模型获得能够反映聚乙烯醇水凝胶（PVAH）力学行为的材料特性，并优化PVAH的组成比以替代人类椎间盘的髓核（NP）。制备了六种类型的PVAH标本（3、5、7、10、15、20 wt%），然后使用Holmes-Mow双相模型进行无侧限压缩实验以获取其材料特性。随着PVAH中PVA重量百分比的增加，杨氏模量增加而渗透系数降低。在15 wt%和20 wt%时，杨氏模量和渗透系数与NP的相似。使用NP模型对腰椎节段进行动态运动分析测得的活动范围、小关节力和NP压力也与15~20 wt% PVAH模型的值相似。考虑到腰椎节段的结构稳定性和疼痛情况，20 wt% PVAH似乎最适合替代NP。
