摘要
目的拟观察骨钉植入所造成的鼠皮质骨机械性显微损伤的形态特征。方法在成年(12个月)大鼠胫骨中段钻入直径1.2mm的含螺纹的克氏针。钻孔骨段经碱性品红染色,甲基丙烯酸甲酯包埋后作100μm厚的横截面切片。骨切片在普通光镜、荧光显微镜和激光共聚焦显微镜下进行观察,并对显微损伤的范围进行定量分析。结果普通光镜和荧光显微镜均可以发现针孔周围的弥散性损伤和线性裂纹,而荧光显微镜能显示普通光镜下难以分辨的染色较弱的显微损伤;激光共聚焦显微镜则具有更高的分辨率,能发现光镜下的片状损伤由很多细小的交叉裂纹组成。定量分析结果显示,损伤骨的厚度一般小于100μm,而荧光显微镜显示的损伤骨表面比率、损伤骨厚度和损伤骨面积均大于普通光镜所示(P<0.05)。结论螺钉植入造成的周围皮质骨显微损伤包括弥散性损伤和线性裂纹。两者均可由极微细的裂纹聚合而成。荧光显微镜由于对碱性品红有更高的敏感性,因儿能提供更为准确的定量分析结果。
Objective The morphological characteristics of mechanically induced microdamage were observed using the model of pin implantation in rat cortical bone. Methods Four adult SD rats were used in this study. A hole was drilled in the tibial diaphysis by a 1.2 mm diameter metal pin with incised threads. The drilled bone segments were stained with basic fuchsin and embedded in methylmethacrylate. Cross sections （100 μm） were cut and observed using bright-field, fluorescence and confocal microscopy. A quantitative analysis was performed for microdamage adjacent to the pin hole. Results Both bright-field and fluorescence microscopy showed diffuse damage and linear cracks around the pin-hole. However, fluorescence microscopy usually showed the weakly stained microdamage that was not visible in bright-field microscopy. Owing to the higher resolution, confocal microscopy could identify the submicroscopic damage that was composed of numerous tiny cross-hatched cracks. Morphological measurements indicated that almost all the pin-hole surface was associated with diffuse damage; the thickness of damaged bone was generally less than 100 μm. The thickness and area of damaged bone were significantly larger in fluorescence microscopy than in bright-field microscopy （P 〈 0.05 ）. Conclusions Microdamage resulting from pin implantation is composed of diffuse damage and linear cracks. Either pattern of microdamage is likely assembled by the accumulation of ultra-cracks. Fluorescence microscopy, due to its higher sensitivity to basic fuchsin, may provide more accurate results for quantitative analysis of microdamage.
出处
《中国骨质疏松杂志》
CAS
CSCD
2007年第4期225-228,242,共5页
Chinese Journal of Osteoporosis
基金
上海市科委白玉兰科技人才基金资助项目(200441)
关键词
皮质骨
显微损伤
裂纹
荧光显微镜
Cortical bone
Microdamage
Cracks
Fluorescence microscopy
