Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland.
Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland; Medical Research Center, University of Oulu, Oulu, Finland.
Osteoarthritis Cartilage. 2021 May;29(5):762-772. doi: 10.1016/j.joca.2021.01.009. Epub 2021 Feb 13.
Knee osteoarthritis (OA) is associated with meniscal degeneration that may involve disorganization of the meniscal collagen fiber network. Our aims were to quantitatively analyze the microstructural organization of human meniscus samples in 3D using micro-computed tomography (μCT), and to compare the local microstructural organization between OA and donor samples.
We collected posterior horns of both medial and lateral human menisci from 10 end-stage medial compartment knee OA patients undergoing total knee replacement (medial & lateral OA) and 10 deceased donors without knee OA (medial & lateral donor). Posterior horns were dissected and fixed in formalin, dehydrated in ascending ethanol concentrations, treated with hexamethyldisilazane (HMDS), and imaged with μCT. We performed local orientation analysis of collagenous microstructure in 3D by calculating structure tensors from greyscale gradients within selected integration window to determine the polar angle for each voxel.
In donor samples, meniscus bundles were aligned circumferentially around the inner border of meniscus. In medial OA menisci, the organized structure of collagen network was lost, and main orientation was shifted away from the circumferential alignment. Quantitatively, medial OA menisci had the lowest mean orientation angle compared to all groups, -24° (95%CI -31 to -18) vs medial donor and -25° (95%CI -34 to -15) vs lateral OA.
HMDS-based μCT imaging enabled quantitative analysis of meniscal collagen fiber bundles and their orientations in 3D. In human medial OA menisci, the collagen disorganization was profound with overall lower orientation angles, suggesting collagenous microstructure disorganization as an important part of meniscus degradation.
膝关节骨关节炎（OA）与半月板退变有关，后者可能涉及半月板胶原纤维网络的紊乱。我们的目的是使用微计算机断层扫描（μCT）对人半月板样本的三维微观结构组织进行定量分析，并比较 OA 和供体样本之间的局部微观结构组织。
我们从 10 例接受全膝关节置换术（内侧和外侧 OA）的终末期内侧间室膝 OA 患者和 10 例无膝 OA 的已故供体（内侧和外侧供体）中收集内侧和外侧半月板的后角。后角在福尔马林中解剖并固定，用递增的乙醇浓度进行脱水，用六甲基二硅氮烷（HMDS）处理，并用μCT 成像。我们通过在选定的积分窗口内计算灰度梯度的结构张量来对 3D 中的胶原微观结构进行局部取向分析，以确定每个体素的极角。
在供体样本中，半月板束沿半月板内缘呈环形排列。在内侧 OA 半月板中，胶原网络的有序结构丢失，主方向偏离环形排列。定量分析显示，与所有组相比，内侧 OA 半月板的平均取向角度最低，为-24°（95%CI -31 至-18），低于内侧供体的-25°（95%CI -34 至-15）和外侧 OA。
基于 HMDS 的μCT 成像能够对人半月板胶原纤维束及其在 3D 中的取向进行定量分析。在人类内侧 OA 半月板中，胶原紊乱非常严重，整体取向角度较低，表明胶原微观结构紊乱是半月板降解的重要组成部分。
