兔胫骨单皮质骨缺损模型和桡骨缺损模型比较研究

A comparative study between tibia unilateral cortical bone defect model and radius bone defect model of rabbits

目的比较兔胫骨上段单皮质8 mm骨缺损与桡骨中段15 mm骨缺损修复差异。方法取3月龄雄性新西兰大白兔10只,体重(2.5±0.3)kg,随机分为两组,利用牙科磨钻分别制备直径为8 mm胫骨上段单皮质骨缺损和15 mm桡骨中段骨缺损模型。造模后伤口常规换药3～5 d,术后4 w、12 w行X光摄片;造模后12 w用micro CT对骨缺损修复行CT平扫及骨组织三维成像;于骨缺损造模后12 w,分别对造模胫骨和桡骨取材,4%多聚甲醛/PBS固定,10%EDTA/PBS脱钙后常规脱水、包埋、切片,HE染色检测骨缺损修复。结果骨缺损12 w时,兔胫骨上段单骨皮质8 mm缺损在无外固定和内固定情况下,X片示骨缺损未能自行愈合,髓腔内有松质骨形成;在无外固定和其他移植物存在的情况下,桡骨中段15 mm骨缺损也未能自行愈合。结论兔桡骨中段15 mm骨缺损和胫骨上段8 mm骨缺损模型均可作为骨缺损不愈合动物模型。

Objective To make comparison of differences between the reparation of 8 mm unilateral cortical bone defect in the superior segment of tibia and 15 mm bone defect in the middle radius in rabbits. Methods Ten three - month - old male New Zealand white rabbits with the weight of（2.5 ± 0.3） kg were selected and randomly divided into two groups. Dental burr was used to prepare the single cortical bone defect model with the diameter of 8 mm in superior tibia and the model of 15 mm bone defect in middle radius. After the modeling,the traditional change of dressing on the wound was carried out for 3 - 5 d,and 4 and 12 w after the operation,those rabbits received the X - ray radiography. Twelve weeks after the modeling,CT plain scanning and bone tissue 3D imaging of the bone defect reparation were made by micro CT. Twelve weeks after the modeling of bone defect,the specimens of the tibia and radius from defect reparation segments were taken out and fixed by 4% paraformaldehyde/PBS. After the decalcification with 10% EDTA/PBS, conventional dehydration, embedding, and slicing were carried out, and the bone defect reparation was detected by the HE staining. Results Twelve weeks after the bone defect, X - ray film showed that the bone defect failed to repair when the 8 mm single bone cortical defect in superior tibia had no external and internal fixation. And there was the formation of cancellated bone within the medullary cavity; under the condition without internal and external fixation and the occurrence of other implants, the 15 mm defect in middle radius also failed to repair. Conclusion The models of 15 mm bone defect in rabbits middle radius and 8 mm single bone cortical bone defect in the superior segment of tibia can both be used as the animal models of bone defect disunion.