Department of Biomedical Engineering, University of Miami, Coral Gables, FL, United States.
Department of Chemical and Materials Engineering, University of Naples, Naples, Italy.
J Biomech. 2021 May 7;120:110343. doi: 10.1016/j.jbiomech.2021.110343. Epub 2021 Mar 1.
The meniscus is crucial in maintaining the knee function and protecting the joint from secondary pathologies, including osteoarthritis. Although most of the mechanical properties of human menisci have been characterized, to our knowledge, its dynamic shear properties have never been reported. Moreover, little is known about meniscal shear properties in relation to tissue structure and composition. This is crucial to understand mechanisms of meniscal injury, as well as, in regenerative medicine, for the design and development of tissue engineered scaffolds mimicking the native tissue. Hence, the objective of this study was to characterize the dynamic and equilibrium shear properties of human meniscus in relation to its anisotropy and composition. Specimens were prepared from the axial and the circumferential anatomical planes of medial and lateral menisci. Frequency sweeps and stress relaxation tests yielded storage (G') and loss moduli (G″), and equilibrium shear modulus (G). Correlations of moduli with water, glycosaminoglycans (GAGs), and collagen content were investigated. The meniscus exhibited viscoelastic behavior. Dynamic shear properties were related to tissue composition: negative correlations were found between G', G″ and G, and meniscal water content; positive correlations were found for G' and G″ with GAG and collagen (only in circumferential samples). Circumferential samples, with collagen fibers orthogonal to the shear plane, exhibited superior dynamic mechanical properties, with G' ~70 kPa and G″ ~10 kPa, compared to those of the axial plane ~15 kPa and ~1 kPa, respectively. Fiber orientation did not affect the values of G, which ranged from ~50 to ~100 kPa.
半月板对于维持膝关节功能和保护关节免受继发性病变（包括骨关节炎）至关重要。尽管已经对人半月板的大部分力学性能进行了描述，但据我们所知，其动态剪切性能从未被报道过。此外，关于半月板剪切性能与组织结构和组成的关系，人们知之甚少。这对于理解半月板损伤的机制以及再生医学中设计和开发模仿天然组织的组织工程支架至关重要。因此，本研究的目的是表征人半月板的动态和平衡剪切性能与其各向异性和组成的关系。标本取自内侧和外侧半月板的轴向和周向解剖平面。频率扫描和应力松弛测试得出了储能模量（G'）和损耗模量（G"）以及平衡剪切模量（G）。研究了模量与水、糖胺聚糖（GAGs）和胶原含量的相关性。半月板表现出粘弹性行为。动态剪切性能与组织组成有关：G'、G"和 G 与半月板含水量呈负相关；G'和 G"与 GAG 和胶原呈正相关（仅在周向样本中）。与剪切平面正交的胶原纤维的周向样本表现出更高的动态力学性能，G'约为 70 kPa，G"约为 10 kPa，而轴向样本分别约为 15 kPa 和 1 kPa。纤维取向不影响 G 的值，其范围约为 50 至 100 kPa。
