摘要
The meniscus plays an important role in the biomechanical function of the knee joint,but knee osteoarthritis(OA)deteriorates the mechanical properties of the meniscus.Thus understanding the mechanical behaviour of the OA meniscus is very important.This study aimed to assess the quasi-static nonlinear mechanical behaviours of the three zones of the OA meniscus by a proposed meso-indentation method,and further to investigate its nonlinear mechanical responses under the stance.Four pairs of menisci were harvested from OA patients during total knee arthroplasty.One pair of the menisci was first used for the histological analysis.Binocular fringe projection technology was then employed to reconstruct the morphology of the other three pairs of the menisci.Subsequently,a meso-indentation method was proposed to characterize the nonlinear behaviors of the meniscus zones,moreover,the hyperelastic model(HEM)together with the Hertz’s elastic model(EM)was used to fit the indentation force-depth curves of the meniscus zones.Furthermore,the fitted HEM and EM materials parameters were used to simulate the mechanical response of the meniscus in the stance by two simplified meniscus models.The results showed that the type Ⅲ collagen widely existed in the OA menisci,and the red-white zone exhibited the best mechanical performance,and the 3-term Mooney-Rivlin model was the best descriptor for the nonlinear mechanical characterization of the three zones.Moreover,the stress or strain distributions of the simplified meniscus models differed significantly between the HEM and EM under the stance,and the EM underestimated the mechanical behaviours of the meniscus.The current work generally provides a novel testing method to study the nonlinear mechanical behaviour of soft biological materials,and is specifically helpful to understand the nonlinear mechanical behaviour of the OA meniscus for which the HEM should be used in the meniscus-related biomechanical studies.
半月板在膝关节的生物力学功能中起着关键作用,但在膝关节骨关节炎(OA)的影响下,其力学性能会产生显著退化,因此了解OA半月板的力学行为至关重要.本研究旨在通过一种新颖的介观压痕实验方法,评估OA半月板不同区域的准静态非线性力学行为,并研究其在站立条件下的力学响应.研究从接受全膝关节置换术的OA患者中获取四对半月板,其中一对用于组织学分析,其余通过双目条纹投影技术进行形态学重建,并采用介观压痕方法来表征半月板各区域的非线性力学行为.研究采用超弹性模型(HEM)和赫兹弹性模型(EM)拟合半月板白区、红白区以及红区的压痕力-深度曲线.进一步基于拟合的HEM和EM模型参数,采用简化有限元模型模拟半月板在站立条件下的力学响应.研究结果显示,OA患者半月板中Ⅲ型胶原含量高,半月板的红白区表现出最佳的力学性能.三参数Mooney-Rivlin模型被认为是描述半月板各区域非线性力学行为的最有效模型.此外,在准静态站立条件下,采用HEM和EM的半月板模型之间的应力和应变分布表现出显著差异,且EM模型低估了半月板的力学响应.本研究提供了一种研究生物软组织非线性力学行为的新方法,有助于更好地描述OA半月板的非线性力学行为,并建议在涉及半月板的生物力学研究中优先采用HEM模型.
基金
supported by the National Nature Science Foundation of China(Grant Nos.32171307,12372307,12172089,61821002 and 82102567)
the Basic Research Plan Natural Science Foundation of Jiangsu Province(Grant No.BK20232023)
the Nature Science Foundation of Jiangsu Province(Grant No.BK20200144)
the Postgraduate Research and Practice Innovation Program of Jiangsu Province(Grant No.5007032303).
