甲状旁腺激素结合煅烧骨治疗兔桡骨临界性缺损

目的：探讨甲状旁腺激素（PTH）结合煅烧骨对兔桡骨临界性缺损的修复作用。方法：36只成年新西兰大白兔,建立兔桡骨中段15mm临界性骨缺损模型,随机分为空白对照组、煅烧骨组、PTH组。分别给予溶剂及间歇性PTH治疗。术后8周,应用影像学、组织学等方法检测缺损处的骨修复情况。结果：术后第8周放射学检测显示,空白对照组桡骨缺损明显,无新骨形成;煅烧骨组缺损处只有少量骨形成;而PTH组煅烧骨与桡骨断端间有连续的骨小梁通过骨折线,缺损处密度明显增高,提示有大量新生骨形成。组织切片中PTH组和煅烧骨组平均新生骨小梁面积百分比分别为0.6270±0.0861和0.2410±0.0715,两组间差异有统计学意义（P=0.0006）。另外,生物力学检测结果显示,PTH组的平均最大载荷为（253.70±41.29）N,而煅烧骨组的平均最大载荷为（144.60±23.20）N,两组间差异有统计学意义（P=0.0341）。结论：联合应用煅烧骨和PTH可以促进骨缺损处新骨的形成,有利于临界性骨缺损的修复。

Repair of critical-size bone defects in the radius of the rabbit using PTH and true bone ceramics

Objective：To study the repairing effects of PTH combined with true bone ceramics（TBC） on critical-size segmental radius defects in rabbit. Methods：Thirty-six adult New Zealand White rabbits, critical-size redius defects were created and were randomized into three groups：Control group,TBC group and PTH group. Each group was treated with sowent,TBC or PTH and TBC respectively. Eight weeks after operation,radiological,histomorphometric and biomechanical evaluation were performed to evaluate the osteogenesis in each group. Results：Eight weeks after surgery,postoperative radiograms showed that the defects were evident and no bone formation was seen in the control group,and only partial bone formation was recognized in the TBC group. While the defect was filled by dense material which indicating a large amount of new bone deposition and a bony bridge was notable in the PTH group. Histological sections revealed the new bone percentage of bone defects was 0.627 0±0.086 1和0.241 0±0.071 5 respectively in the TBC and PTH group,which had significant differences（P=0.000 6）. The maximum load for fracturing in the PTH and TBC group was（253.70±41.29） N and（144.60±23.20） N respectively,which also had significant differences（P=0.034 1）. Conclusion：Osteogenesis can be promoted by PTH and TBC,which is an appropriate tool to induce bone healing in atrophic nonunions.