Non-invasive Densitometric and Histomorphometric Study of the Regenerated Bone in the Distraction Gap in Rabbits.

牵张成骨的一个显著缺点是牵张完成后需要长时间的外固定，这是获得足够的强度来抵抗无固定所必需的。本研究的目的是了解再生骨的力学性能，并试图找到一个合适的时机，安全地取出固定装置。将外固定装置应用于兔右侧胫骨，并在胫腓骨交界处下方进行横向截骨术。术后以0.72mm/d的速度延长胫骨7.2mm，连续10 d。A.通过外周定量计算机断层扫描分析的骨矿物质密度（BMD）和应力应变指数（SSI）显示在第40天显著增加，但在完成牵张后的第64天恢复到对照水平。因此，宿主皮质骨之间的新形成的骨似乎足以抵抗本研究中巩固期第40天的机械应力。目前的结果表明，在骨密度和SSI在巩固期显示出显着高水平时，拆除固定装置的可能性。

The long period of external fixation after the completion of distraction, which is necessary to obtain enough strength for resisting without fixation is a significant disadvantage of distraction osteogenesis. The purpose of this study is to understand the mechanical property of the regenerated bone and try to find an appropriate timing for safely removing the fixation device. A external fixation device was applied to the right tibia in rabbits and transverse osteotomy was performed just below the tibio-fibula junction. The tibiae were lengthened 7.2 mm at 0.72 mm a day for 10 days after surgery. A.bone mineral density (BMD) and stress strain index (SSI) analyzed by peripheral quantitative computed tomography showed a significant increase on day 40, but returned to the control level at day 64 after the completion of distraction. Therefore, the newly formed bone between the host cortical bone seemed to be enough to resist the mechanical stress on day 40 during the consolidation period in this study. The present results suggested the possibility of removing the fixation device during the period when the BMD and SSI showed a significantly high level during the consolidation period.