兔椎体成形术后骨水泥-骨界面组织形态学观察和骨钙素动态表达研究

Observation on the histomorphological changes and study of the dynamic expression of OC at the bone cement interface of rabbit after vertebroplasty

目的:观察兔椎体成形术后骨水泥-骨界面组织形态学变化和骨钙素(Osteocalcin,OC)动态表达及意义。方法:24只骨质疏松新西兰大白兔随机分成聚甲基丙烯酸甲酯(Polymethylmethacrylate,PMMA)组和对照组,实验组建立椎体成形术模型,对照组只进行手术不注射骨水泥,分别于术后1、24 h、3 d、7 d、4周、12周行X线观察椎体内骨水泥情况,处死兔子,取实验椎体,行HE染色观察骨水泥-骨界面组织学形态变化,用免疫组化方法检测骨水泥-骨界面OC蛋白的动态表达水平。结果:术后PMMA组X线正侧位片显示手术椎体内骨水泥无脱落、松动,骨水泥体积未发生明显变化。对照组椎体手术部位见约0.5 cm大小直径的圆形低密度区。术后取标本,见PMMA与周围组织紧密结合,骨水泥体积较术前无明显变化。HE染色,对照组的骨愈合过程与正常骨组织一致,但有所延迟,PMMA周围未见明显组织坏死。PMMA组和对照组骨水泥界面OC表达在术后逐渐增高,但PMMA组较对照组有所延迟。结论:PMMA骨水泥-骨界面有一定的炎症反应,较对照组有所延迟,表明PMMA的放热反应和单体毒性不会造成骨组织永久坏死;PMMA骨水泥-骨界面修复过程中OC高表达,比正常愈合过程有所延迟,表明局部骨组织细胞功能未受不可逆损害。

Objective：To observe the histomorphological changes and study the dynamic expression of OC at the bone cement interface of rabbit after vertebroplasty.Methods：24 New-Zealand rabbits with osteoporosis were randomly divided into two groups,including experimental group and control group.The experimental group were established into vertebroplasty model,and the procedure in control group was completed without bone cement injection.Respectively,at 1,24 h,3 d,7 d,4 w and 12 w,rabbits from each group were killed by aeroembolism.The operative vertebral bodies were taken out as research objects.The histomorphological changes were observed by HE staining and the OC expression of the rabbits was studied by immunohistochemistry stain at the bone cement interface.Results：At all of the injected sites,there was intimate contact between the cement and the surrounding tissue in experimental group.The volume of PMMA had no prominent changes.There was a 0.5 cm low density area in the puncture site in the control group.After the operative vertebra was taken out,it was observed that PMMA was closely integrated with the surrounding tissue.Bone cement volume had no significant change compared with the preoperative volume.The control group showed normal bone healing process in HE staining.The bone cement was closely integrated with bone surrounding tissue in experimental group.There was no osteonecrosis between PMMA and surrounding tissue.The OC expression increased in both groups after surgery.Compared with the control group,the OC expression of experimental group was delayed.Conclusion：There is inflammatory reaction at the bone cement interface,and it is delayed compared with the control group.It indicates that the exothermic reaction of PMMA and monomer toxicity do not cause permanent bone necrosis.During the curing process,the OC shows high expression,which is delayed compared with control group.This demonstrates that the function of local bone tissue and cells doesn＇t suffer irreversible damage.