University of Oxford, Oxford, UK.
Department of Health Science and Technologies, ETH, Zurich, Switzerland.
Ann Biomed Eng. 2021 Sep;49(9):2421-2429. doi: 10.1007/s10439-021-02792-1. Epub 2021 Jun 1.
The knee meniscus is a highly porous structure which exhibits a grading architecture through the depth of the tissue. The superficial layers on both femoral and tibial sides are constituted by a fine mesh of randomly distributed collagen fibers while the internal layer is constituted by a network of collagen channels of a mean size of 22.14 [Formula: see text]m aligned at a [Formula: see text] inclination with respect to the vertical. Horizontal dog-bone samples extracted from different depths of the tissue were mechanically tested in uniaxial tension to examine the variation of elastic and viscoelastic properties across the meniscus. The tests show that a random alignment of the collagen fibers in the superficial layers leads to stiffer mechanical responses (E = 105 and 189 MPa) in comparison to the internal regions (E = 34 MPa). All regions exhibit two modes of relaxation at a constant strain ([Formula: see text] to 7.7 s, [Formula: see text] = 49.9 to 59.7 s).
膝关节半月板是一种高度多孔的结构，其在组织深度上表现出分级结构。股骨和胫骨两侧的表面层由随机分布的胶原纤维细网组成，而内层由胶原通道网络组成，平均大小为 22.14 [Formula: see text]m，相对于垂直方向呈 [Formula: see text]的倾斜排列。从组织的不同深度提取的水平狗骨样本来进行单轴拉伸力学测试，以检查半月板的弹性和粘弹性特性的变化。测试表明，在浅层中胶原纤维的随机排列导致更硬的机械响应（E = 105 和 189 MPa）与内部区域（E = 34 MPa）相比。所有区域在恒定应变下都表现出两种弛豫模式([Formula: see text]至 7.7 s，[Formula: see text] = 49.9 至 59.7 s)。
