应力遮挡性骨皮质骨质疏松症的病理组织学与骨四环素荧光标记观察

Observation of Histopathology and Tetracycline Fluorescence Marked Changes in Cortical Osteoporosis for Stress Shielding

目的:了解骨折钢板内固定对骨折局部骨皮质的病理组织学改变与四环素荧光标记的变化。方法:将家兔胫骨制成标准横断骨折模型,后安放加压钢板。术后进行四环素活体标记,在术后5、10和15周截取标本拍片,分别进行大体计量观察与骨不脱钙切片的组织学与荧光显微镜下观察。结果:组织学观察发现,随术后固定时间的延长,钢板被骨痂包绕的越紧密,后期钢板周边骨痂呈皮质骨样结构。钢板下与钢板对侧皮质骨出现大块的“穿凿样”皮质骨吸收区,并出现破骨细胞性骨吸收与骨重建性四环素双标记线。结论:在加压钢板内固定术后,骨折局部皮质骨均有明显的骨质疏松改变,并随固定时间的延长而加重。

Objective: To evaluate the histopathology and tetracycline fluorescence marked changes in cortical osteoporosis of the local site of fracture after inter plate fixation for stress shielding. Methods: A rabbit model of tibia transverse fracture was made, then fixed with internal plate and marked with tetracycline. At 5, 10 and 15 weeks after fixation, the specimens were taken for studying the measurement grossly, histipathological section and undecalicified section by fluorescence microscopy. Results: Under the microscope, the plate was surrounded by callus as the time of fixation extended, and the callus changed into cortex bone. Under the plate, many large punched-out absorbing aears in cortex bone were found, where the osteoclasts and bone remodeling in double lines of tetracycline were also observed about the sites of plate underneath. Coclu-sion: At 5, 10 and 15 weeks after fixation, the osteoporosis in cortical bone were progressed at the fracture site.