骨质疏松性骨折愈合中骨改建的动态参数及骨密度变化

背景：当骨质疏松骨强度下降时，遭受轻微创伤或其他各种风险因素均易发生骨折。 目的：观察骨质疏松性骨折愈合过程中骨小梁组织学变化，骨密度及骨矿化沉积率的改变。 方法：SD大鼠随机分为骨质疏松组与对照组，骨质疏松组大鼠切除双侧卵巢，术后3个月，建立骨折模型。骨折后4，8，12，16 周，荧光显微镜下观察骨改建的动态参数，双能X线骨密度仪下测定骨痂组织的骨密度；骨折后1，2，4，6，8，12，16 周，应用自动图像系统测量骨组织形态。 结果与结论：骨质疏松组大鼠成熟小梁骨占骨痂面积比对照组小，且小梁骨厚度变薄、小梁骨间距较宽，骨质疏松组骨小梁表面荧光标记百分比及骨痂组织骨密度低于对照组；而骨矿化沉积率高于后者对照组。说明在骨质疏松性骨折愈合过程中，骨痂组织的组织学的异常改变导致骨折愈合质量的降低。

Changes in bone reconstruction dynamic parameters and bone mineral density during osteoporotic fracture healing

BACKGROUND: When osteoporotic bone strength decreases, slight trauma or other risk factors would cause fracture. OBJECTIVE: To observe the changes in trabecular bone, bone mineral density and bone mineral apposition rate during osteoporotic fracture healing. METHODS: Sprague-Dawley rats were randomly divided into osteoporosis and control groups. Rats from osteoporosis group underwent bilateral ovariectomy and 3 months later, fracture model was created. At 4, 8, 12 and 16 weeks after fracture, dynamic parameters of bone reconstruction were determined using fluorescence microscope, and bone mineral density of callus was determined using dual-energy X-ray absorptiometry. At 1, 2, 4, 6, 8, 12 and 16 weeks after fracture, bone histomorphology was measured using automatic image system. RESULTS AND CONCLUSION: Compared with the control group, the ratio of mature trabecular bone to callus was lower, trabecular bone thickness was less, distance between trabecular bones was greater, percentage of trabecular bone surface fluorescence labeling and bone mineral density in callus were lower, but bone mineral apposition rate was higher, in the osteoporosis group. Results showed that abnormal changes of callus microanatomy result in decreased mechanical strength or quality of fractured bone during osteoporotic fracture healing.