Li Wei, Zhao Guang-feng, Xu Shao-wen, Wang Jian-wei, Zhou Yi-fei, Liu Jian
Department of Orthopaedics, Second Affiliated Hospital, Medical College, Zhejiang University, Hangzhou 310009, China.
Chin J Traumatol. 2005 Apr;8(2):121-5.
To dynamically monitor the bone mineral density (BMD) and the histomorphological changes during fracture healing in a rat femoral fracture model and to explore the role of dual energy X-ray absorptiometry (DEXA) in evaluating bone fracture healing.
Sixty three-month-old female Sprague Dawley rats were used to establish right femoral fracture models. The BMD of the callus of the fractured right femur were scanned by DEXA at 2, 4, 6, 8, 10 and 12 weeks after operation, respectively. A light microscope was used to evaluate the callus of each rat at the same time. The corresponding segment of the left femur was taken as a control.
The BMD at the fractured site increased significantly during the process of fracture healing, which shows an obvious healing trend. The callus BMDs were 29.5%, 48.3%, 85.3%, and 105.2% of the BMD of the control limb at 2, 4, 6 and 8 weeks after fracture, respectively. There was a significantly difference between the groups. A compatibility on time was found between the BMD and the histomorphological characteristics at the fractured site during the process of fracture healing. The fracture healing was almost completed at 8 weeks after fracture as assessed by its histomorphological characteristics when the callus BMD reached to 105.2% of the BMD of the control limb. The BMD of the distal metaphysis decreased until 12 weeks after fracture.
DEXA can evaluate the mineralization of the callus during the fracture healing process accurately and quantitatively and is more sensitive than plain radiography in detecting impaired bone unions, which indicates that it may play an important role in monitoring fracture healing.
在大鼠股骨骨折模型中动态监测骨折愈合过程中的骨密度（BMD）及组织形态学变化，探讨双能X线吸收法（DEXA）在评估骨折愈合中的作用。
选用60只3月龄雌性Sprague Dawley大鼠建立右侧股骨骨折模型。分别于术后2、4、6、8、10和12周用DEXA扫描右侧骨折股骨骨痂的骨密度。同时用光学显微镜评估每只大鼠的骨痂情况。取左侧股骨相应节段作为对照。
骨折愈合过程中骨折部位的骨密度显著增加，呈现明显的愈合趋势。骨折后2、4、6和8周时骨痂骨密度分别为对照肢体骨密度的29.5%、48.3%、85.3%和105.2%。各组间差异有统计学意义。骨折愈合过程中骨折部位的骨密度与组织形态学特征在时间上具有一致性。根据组织形态学特征评估，骨折后8周骨折愈合基本完成，此时骨痂骨密度达到对照肢体骨密度的105.2%。骨折后12周前干骺端骨密度持续下降。
DEXA能准确、定量地评估骨折愈合过程中骨痂的矿化情况，在检测骨愈合受损方面比X线平片更敏感，表明其在监测骨折愈合中可能发挥重要作用。
