Loading-induced changes on topographical distributions of the zonal properties of osteoarthritic tibial cartilage--A study by magnetic resonance imaging at microscopic resolution.
Loading-induced changes on topographical distributions of the zonal properties of osteoarthritic tibial cartilage--A study by magnetic resonance imaging at microscopic resolution.
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DOI：
10.1016/j.jbiomech.2015.08.011
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发表时间：
2015-10-15
影响因子：
2.4
通讯作者：
Xia Y
中科院分区：
文献类型：
--
作者：
Lee JH;Badar F;Kahn D;Matyas J;Qu X;Xia Y
采用显微磁共振成像（μMRI）技术，观察了实验性骨关节炎（OA）模型胫骨内侧关节软骨在外部载荷作用下的区域性分布特征。T2弛豫时间和软骨厚度在17.6μm分辨率下测量，来自13只狗（术后8周6只，术后12周7只）的118个标本，有和没有机械负荷。此外，从每个胫骨表面形貌测量体积机械模量。外载荷作用下，总厚度显著减小，其中表浅区（SZ）和过渡区（TZ）的相对厚度增加，而径向区（RZs）的相对厚度减小。在整体数据中，T2（55°）在所有OA时间点均显著降低（p<0.001），但T2（0°）在8周时无显著性降低（p>0.05）。复杂的关系被发现在带状组织的属性作为一个功能的外部负载与OA的进展。在所有OA时间点，作为外部负荷的函数，浅表区的T2比径向区的相同特性变化更深刻。这项研究证实，OA影响的分子分布和结构的软骨，这是深度依赖性和地形分布的负荷引起的变化。对特定胫骨软骨区域和位置的机械生物学变化以及OA进展的详细了解可以改善对伴随OA临床前阶段的软骨微妙软化的早期检测。
The topographical distributions of the zonal properties of articular cartilage over the medial tibia from an experimental osteoarthritis (OA) model were evaluated as the function of external loading by microscopic Magnetic Resonance Imaging (μMRI). T2 relaxation times and cartilage thicknesses were measured at 17.6μm resolution from 118 specimens, which came from thirteen dogs (six 8-week and seven 12-week after surgery), with and without mechanical loading. In addition, bulk mechanical modulus was measured topographically from each tibia surface. The total thickness decreased significantly under the external loading, in which the relative thickness of the superficial zone (SZ) and the transitional zone (TZ) increased whereas the radial zones (RZs) decreased. In the bulk data, T2(55°) decreased significantly (p<0.001) at all OA-time-points, but T2(0°) decreased without significance (p>0.05) at 8-week. Complex relationships were found in the zonal tissue properties as a function of external loading with the progress of OA. T2 in the superficial zone changed more profoundly than the same properties in the radial zone as the function of external loading at all OA time-points. This study confirms that the OA affects the load-induced changes in the molecular distribution and structure of cartilage, which are both depth-dependent and topographically distributed. Such detailed knowledge of mechanobiological changes in specific tibial cartilage zones and locations with OA progress could improve the early detection of the subtle softening of cartilage that accompany pre-clinical stages of OA.