Touraine Sébastien, Bouhadoun Hamid, Engelke Klaus, Laredo Jean Denis, Chappard Christine
B2OA, UMR CNRS 7052, University Paris Diderot, Paris, France.
Service de Radiologie Ostéo-Articulaire, Hôpital Lariboisière, Paris, France.
PLoS One. 2017 Aug 10;12(8):e0181956. doi: 10.1371/journal.pone.0181956. eCollection 2017.
Cartilage and subchondral bone form a functional unit. Here, we aimed to examine the effect of meniscus coverage on the characteristics of this unit in knees of older individuals.
We assessed the hyaline cartilage, subchondral cortical plate (SCP), and subchondral trabecular bone in areas covered or uncovered by the meniscus from normal cadaver knees (without degeneration). Bone cores harvested from the medial tibial plateau at locations uncovered (central), partially covered (posterior), and completely covered (peripheral) by the meniscus were imaged by micro-CT. The following were measured on images: cartilage volume (Cart.Vol, mm3) and thickness (Cart.Th, mm); SCP thickness (SCP.Th, μm) and porosity (SCP.Por, %); bone volume to total volume fraction (BV/TV, %); trabecular thickness (Tb.Th, μm), spacing (Tb.Sp, μm), and number (Tb.N, 1/mm); structure model index (SMI); trabecular pattern factor (Tb.Pf); and degree of anisotropy (DA).
Among the 28 specimens studied (18 females) from individuals with mean age 82.8±10.2 years, cartilage and SCP were thicker at the central site uncovered by the meniscus than the posterior and peripheral sites, and Cart.Vol was greater. SCP.Por was highest in posterior samples. In the upper 1-5 mm of subchondral bone, central samples were characterized by higher values for BV/TV, Tb.N, Tb.Th, and connectivity (Tb.Pf), a more plate-like trabecular structure and lower anisotropy than with other samples. Deeper down, at 6-10 mm, the differences were slightly higher for Tb.Th centrally, DA peripherally and SMI posteriorly.
The coverage or not by meniscus in the knee of older individuals is significantly associated with Cart.Th, SCP.Th, SCP.Por and trabecular microarchitectural parameters in the most superficial 5 mm and to a lesser extent the deepest area of subchondral trabecular bone. These results suggest an effect of differences in local loading conditions. In subchondral bone uncovered by the meniscus, the trabecular architecture resembles that of highly loaded areas.
软骨和软骨下骨形成一个功能单元。在此，我们旨在研究半月板覆盖情况对老年个体膝关节中该单元特征的影响。
我们评估了来自正常尸体膝关节（无退变）半月板覆盖或未覆盖区域的透明软骨、软骨下皮质板（SCP）和软骨下小梁骨。从半月板未覆盖（中央）、部分覆盖（后部）和完全覆盖（周边）的内侧胫骨平台位置采集骨芯，通过显微CT成像。在图像上测量以下指标：软骨体积（Cart.Vol，mm³）和厚度（Cart.Th，mm）；SCP厚度（SCP.Th，μm）和孔隙率（SCP.Por，%）；骨体积与总体积分数（BV/TV，%）；小梁厚度（Tb.Th，μm）、间距（Tb.Sp，μm）和数量（Tb.N，1/mm）；结构模型指数（SMI）；小梁模式因子（Tb.Pf）；以及各向异性程度（DA）。
在研究的28个标本（18名女性）中，个体平均年龄为82.8±10.2岁，半月板未覆盖的中央部位的软骨和SCP比后部和周边部位更厚，且Cart.Vol更大。SCP.Por在后部样本中最高。在软骨下骨的上1 - 5 mm处，中央样本的特征是BV/TV、Tb.N、Tb.Th和连通性（Tb.Pf）值更高，小梁结构更呈板状，各向异性比其他样本更低。在更深的6 - 10 mm处，中央部位的Tb.Th差异稍高，周边部位的DA差异稍高，后部的SMI差异稍高。
老年个体膝关节半月板的覆盖与否与最表层5 mm以及软骨下小梁骨最深区域的Cart.Th、SCP.Th、SCP.Por和小梁微结构参数显著相关。这些结果提示了局部负荷条件差异的影响。在半月板未覆盖的软骨下骨中，小梁结构类似于高负荷区域。
