兔颅顶骨临界骨缺损模型的构建

Establishment of a rabbit model of calvarial critical bone defects

目的建立兔颅顶骨临界骨缺损模型。方法选取18只新西兰大白兔,在颅骨制备3个直径分别为4 mm、5 mm、6 mm的圆形全层贯通骨缺损,术后4周、8周、12周取颅骨标本,使用Micro-CT和组织学分析法分析骨缺损的愈合情况。结果骨缺损建模后12周内,4 mm组各时间段骨愈合能力显著优于其他两组,部分出现完整的骨桥连接。5 mm、6 mm组只在缺损区周缘出现少量成骨,缺损中央区主要被纤维结缔组织所充填。这两组成骨量在4周及8周时均不足10%,12周时两组成骨量均接近缺损总面积的10%。结论在术后12周的观察期内,直径≥5 mm的圆形全层兔颅顶骨缺损均不能自行愈合,符合临界骨缺损的标准,可确定为兔颅顶骨临界骨缺损的参考值。

Objective To establish a critical bone defect model of the cranial bone in rabbits.Methods Three full-thickness round bone defects with diameters of 4 mm,5 mm,and 6 mm were created in the skull of 18 New Zealand white rabbits.The defects were analyzed using Micro-CT and histologic analysis after the animals were sacrificed at 4 weeks,8 weeks,or 12 weeks postoperatively.The results were analyzed statistically.Results Within 12 weeks,the bone healing capacity of the 4 mm group at each time point was sig-nificantly better than that of the other two groups.Complete bone bridge connections appeared in 4 mm group.In the other two groups,only a small amount of osteogenesis appeared in the periphery of defect area.The central area of the defect was mainly filled with fibrous connective tissue.The bone mass of these two groups was less than 10%at 4 and 8 weeks,and close to 10%of the total defect area at 12 weeks.Conclusions During the 12 weeks,a round full-thickness rabbit cranial bone defect with a diameter greater than 5 mm could not be self-healed.This meets the criteria of critical bone defect and can be determined as the critical size defect(CSD)of the rabbit cranium.