两种建立兔桡骨感染性骨缺损动物模型方法的比较

Comparison of two methods to build an animal model for infective radius defect in rabbit

目的 比较兔桡骨感染性骨缺损模型两种制作方法的差异,为骨组织工程的研究提供参考.方法 选用6月龄新西兰兔50只,分A0～A4组和B0～B4组,A组先行桡骨钻孔注入不同量[1×10^6～1 ×10^9菌落形成单位（CFU）]的金黄色葡萄球菌制造骨感染,术后4周清创并制造1 cm长度的骨缺损,B组先制作1 cm长度的桡骨骨缺损,再注入不同量金黄色葡萄球菌,A0及B0组为生理盐水对照组.两组术后当日及其术后2、4、6、8周行X线检查,术后8周处死取桡骨作肉眼观察评分、组织学评分及细菌学检查.结果 术后A4组1只、B3组2只、B4组3只死于严重感染;A3、A4组二次手术术中各死亡1只;A3、A4组和B2、B3、B4组实验兔术后体重明显减轻;A4、B3、B4组术后8周X线片示骨缺损部位未见修复.肉眼观察评分方面,在同等细菌量的情况下,B组较A组高,但其差异无统计学意义（P＞0.05）;组织学评分结果显示,在同等细菌量的情况下,B组评分较A组高,其中A2与B2、A3与B3、A4与B4组间评分差异具有统计学意义（P＜0.05）;细菌学检查除A1及空白组,其余各组均培养出细菌.结论 采用骨缺损同时感染的方法制作感染性骨缺损模型所需细菌用量较少,具有较高的感染率、感染症状典型且较为接近临床感染性骨缺损的发病机制,适合感染性骨缺损动物模型的建立.

Objective Theres are two methods to establish an animal model for infective radius defect in rabbit.The aim of this study was to compare the effectiveness of the two methods to promote the development of bone tissue engineering.Methods Fifty six-month-old male New Zealand white rabbits were divided into group A0-A4 and group B0-B4.Bone defects were created bilaterally in the radius and different doses of staphylococcus aureus [1 × 106-1 × 109 colony forming units（CFU）] were inoculated in group A.1 cm bone defect was created after 4 weeks.1 cm defect were made in rabbits of group B,and different doses of staphylococcus aureus were inoculated at the same time.Group A0 and B0 were saline control groups.X-ray was taken immediately after surgery,2-week,4-week,6-week and 8-week postoperatively.The rabbits were sacrificed eight weeks after surgery and the specimens were harvested for gross bone pathological score,pathologic analysis and bacterial cultivation.Results There were 6 rabbits dead of infection （one in group A4,two in group B3 and three in group B4）.Two rabbits （one in group A3 and the other in group A4） died during the 2nd operation.Weight loss was detected in group A3,A4 and group B2,B3,B4.The bone defect was not repaired in group A4,B3,B4 accroding to the X-ray films 8 weeks postoperatively.With same doses of staphylococcus aureus,the histological score and gross bone pathological score of group B were higher than those of group A but without significant difference.In terms of histological score,significant differences was observed between group A2 and B2,group A3 and B3,group A4 and B4,respectively.Bacteria was cultured in the radius in all groups except for saline control groups and group A1.Conclusion The method of creating bone defects and inoculating bacteria at the same time needs less bacteria and has high infection rate.It is relatively close to the clinical pathogenesis.The method of this investigation is convenient and satisfactory,which may be considered as an alternative to establish the radius infective bone defect model in rabbits.