人股骨头坏死微观结构及成骨、破骨细胞活性的区域性分布特征

 目的 比较人股骨头坏死标本不同区域的骨微观结构及成、破骨细胞活性。方法 收集2011年3月至2013年5月行全髋关节置换的非创伤性股骨头坏死患者术后的股骨头标本10例（Ficat Ⅳ期），男6例，女4例；年龄40～57岁，平均47.7岁。Micro-CT扫描后，根据影像学识别骨质密度不同，将每个标本分为软骨下骨区、坏死区、硬化区、健康区，通过病理学检测、纳米压痕、实时荧光定量PCR、免疫组化染色等方法对不同区域的骨微观结构、微观力学性能及成骨、破骨细胞活性进行比较。结果 Micro-CT结果显示，股骨头坏死标本软骨下骨区及坏死区的骨小梁连续性破坏；硬化区的骨小梁数目增多，间隙变窄；正常区域骨小梁结构完整，厚度分布均匀。软骨下骨区、坏死区、硬化区和健康区骨小梁的弹性模量分别为（13.808±4.22） GPa、（13.999±3.816） GPa、（17.266±3.533） GPa和（11.927±1.743） GPa；硬度分别为（0.425±0.173） GPa、（0.331±0.173） GPa、（0.661±0.208） GPa和（0.423±0.088） GPa。抗酒石酸酸性磷酸酶（Trap）染色结果显示，软骨下骨区和坏死区可见Trap染色阳性细胞，硬化区及健康区未见Trap染色阳性细胞。免疫组化染色结果显示，骨形成相关因子Runx2和BMP2在硬化区及健康区表达高于其他区域；骨吸收相关因子RANK和RANKL在软骨下骨区及坏死区表达高于其他区域。结论 股骨头坏死塌陷过程中，骨微观结构发生明显改变，而坏死区骨小梁微观力学强度较健康区无显著降低。股骨头坏死标本中软骨下骨区及坏死区破骨细胞活性增强，硬化区成骨细胞活性增强。

Microstructure and the regional distribution characteristics of osteoblast and osteoclast activity in the sample of the osteonecrosis femoral heads

Objective To compare the bone microstructure and osteoblast and osteoclast activity in different regions of osteonecrosis of the femoral head. Methods The osteonecrosis femoral heads were collected from 10 patients (Ficat IV) who had undergone total hip arthroplasty from March 2011 to May 2013. There were 6 males and 4 females. Their average age was 47.7 years old (range, 40-57 years). The samples were divided into subchondral bone region, necrotic region, sclerosis region and healthy region according to radiographic results, then the bone microstructure, micro mechanism and osteoblasts/osteoclasts activity were analyzed byMicro-CT, RT-PCR, Nanoindentation, immunohistochemistry and Trap staining. Results According to the micro-CT results, the continuity of trabecular bone in necrotic region was damaged. The number of trabecular was increased and the gap was narrowed in sclerosis region. The shape and number of trabecular bone were normal in the healthy region. The elasticity moduli in different regions were: subchondral bone region 13.808?4.22 GPa, necrotic region 13.999?3.816 GPa, sclerosis region 17.266?3.533 GPa and healthy region 11.927?1.743 GPa. The hardness were subchondral bone region 0.425?0.173 GPa, necrotic region 0.331?0.173 GPa, sclerosis region 0.661?0.208 GPa, and healthy region 0.423?0.088 GPa. The trap staining of subchondral bone in healthy region and necrotic region were positive while other regions were negative. Immunohistochemistry staining showed that compared with necrotic region, the RANK and RANKL staining level increased significantly in subchondral bone and necrotic region, while Runx2 and BMP2 staining level increased significantly in sclerosis region. Conclusion The mechanical properties of trabecular have no significant difference between necrotic region and healthy region in the progress of the osteonecrosis, while the bone structure has obvious changes. An active bone resorption is observed in subchondral bone and necrotic region, while a higher bone formation activity is found in sclerosis region.