Abstract: Objective: To study the change of bone meneral density (BMD) in distraction osteogenesis (DO), and to evaluate a new measurement method of BMD. Methods: 24 rabbits were randomly divided into 6 groups: control group and 1 day, 1 week, 2 weeks, 4 weeks, 6 weeks after DO groups. Each group included 4 rabbits. BMD was measured by Archimedes principle and by single X-ray absorptiometry (SXA), respectively. Calcium content in bone was measured by spectrometer. Results: BMD measured both by Archimedes principle and SXA and calcium content measured by spectrometer showed an increase in the distraction zone. There was no significant difference between the 6 weeks group and the control group (P>0.05). The BMD measured by Archimedes principle and by SXA had a positive correlation. The regression equation was YSXA=-0.227+0.457XArchimedes. BMD and calcium content in bone had a positive correlation. The regression equation was Ycalcium content=-623.579+483.473XBMD. Conclusions: Though the measurement method by Archimedes principle was not advanced, it could accurately monitor the change of BMD in DO, simplify the experiment process, and reduce research cost. Therefore, it could be widely used in experimental research. Combined with calcium content analysis, it can accurately monitor the changes of bone structure during osteogenesis.

Key words: Distraction osteogenesis, Bone mineral density, SXA, Archimedes principle, Calcium content