Norrdin R W, Kawcak C E, Capwell B A, McIlwraith C W
Department of Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523, USA.
Bone. 1999 Feb;24(2):109-14. doi: 10.1016/s8756-3282(98)00157-4.
The calcified layer of articular cartilage is known to be affected by age and mechanical factors that may play a role in the development of arthrosis. Because these factors are also related to subchondral remodeling and sclerosis, a morphometric study was carried out in fluorochrome-labeled animals to determine whether the level of subchondral remodeling affected the thickness of the calcified cartilage layer and its irregularity and vascularity at the interface with subchondral bone. These parameters were also studied at a site of increased mechanical stress. The area and thickness of the calcified cartilage layer was determined in basic fuchsin-stained ground sections (120 microm). The irregularity of the chondro-osseous interface was expressed as the ratio of its length to that of the relatively straight tidemark (Int/Tid) and the number of abutting vessels with and without fluochrome labels were counted (N.Ves/Tid,%L.Ves/Tid). These were compared with single-labeled surface (sLS/BS, %) in subchondral bone, which was used as an index of remodeling. In a group of 12 horses, in which one carpus had an osteochondral fragment surgically created 10 weeks earlier, there was activation of subchondral remodeling in the third carpal bone opposite the fragment. An increase in %L.Ves/Tid (p < 0.01) at the interface was correlated with the increase in %sLS/BS in subchondral bone (r=0.431, p=0.035). The number of abutting vessels and the interface irregularity were not significantly changed on the fragmented side. In the metacarpal condyles from the fetlock joints of the same horses there were no differences associated with the surgically created fragment in the carpus and no correlation of %L.Ves/Tid with subchondral %sLS/BS. At a site where mechanical overload and traumatic osteochondrosis is known to occur on the palmar surface, the calcified cartilage was thinner, and the interface irregularity tended to be greater. These findings indicate that activated subchondral remodeling extends to involve the calcified layer, but the thickness and irregularity of the calcified cartilage are not consistently related to current subchondral remodeling. At sites of mechanical overload the calcified cartilage was thinner and the interface tended to be more irregular, suggesting previous increased remodeling.
已知关节软骨的钙化层会受到年龄和机械因素的影响，这些因素可能在关节病的发展中起作用。由于这些因素也与软骨下重塑和硬化有关，因此在荧光标记的动物中进行了一项形态计量学研究，以确定软骨下重塑的程度是否会影响钙化软骨层的厚度及其与软骨下骨界面处的不规则性和血管分布。还在机械应力增加的部位对这些参数进行了研究。在碱性品红染色的磨片（120微米）中测定钙化软骨层的面积和厚度。软骨-骨界面的不规则性表示为其长度与相对笔直的潮标长度之比（Int/Tid），并计算有和没有荧光标记的邻接血管数量（N.Ves/Tid，%L.Ves/Tid）。将这些与软骨下骨中的单标记表面（sLS/BS，%）进行比较，后者用作重塑的指标。在一组12匹马中，其中一只腕关节在10周前通过手术制造了一个骨软骨碎片，在碎片相对的第三腕骨中发生了软骨下重塑激活。界面处%L.Ves/Tid的增加（p<0.01）与软骨下骨中%sLS/BS的增加相关（r=0.431，p=0.035）。碎片侧的邻接血管数量和界面不规则性没有明显变化。在同一匹马的跗关节掌骨髁中，与腕关节手术制造的碎片没有差异，并且%L.Ves/Tid与软骨下%sLS/BS没有相关性。在已知掌面发生机械过载和创伤性骨软骨病的部位，钙化软骨较薄，界面不规则性往往更大。这些发现表明，激活的软骨下重塑会扩展到钙化层，但钙化软骨的厚度和不规则性与当前的软骨下重塑并不始终相关。在机械过载部位，钙化软骨较薄，界面往往更不规则，提示先前重塑增加。
