Abstract: Objective To establish a model of tibial bone defect in rats prepared by Kirschner wire cortical fixation method, and to evaluate it by imaging. Method A total of 30 ( Sprague-Dawley, SD) rats were divided into three groups: sham group, fixed group and unfixed group, with 10 rats in each group, the fixed group and the non-fixed group had bone defects caused by chainsaws in the middle of the tibia, the width of the defect was 2 mm, the depth was 2 mm, the fixed group was fixed in the bone cortex with K-wire ( the non-fixed group did not use K-wire ) , and the sham group only exposed the middle tibia. Micro computed tomography ( Micro-CT) , Hematoxylin-eosin staining ( HE staining ) , Masson’ s trichrome staining, Safranin O / Fast green staining, Toluidine blue staining was used to evaluate the bone defect model and healing. Result The success rate of modeling in the fixed group was 100% and 60% in the unfixed group on the 3rd day after surgery (P<0. 05) . The height and width of the bone defect were (1. 65±0. 21) mm and ( 1. 99±0. 15) mm measured by Micro-CT on the 3 days after operation, and the width and height of the bone defect were ( 1. 38±0. 17) mm and ( 1. 77±0. 16) mm on the 14 days after surgery. Micro-CT result were consistent with tissue sectioning result. Conclusion In this study, the K-wire cortical fixation method was used to prepare the defect model, and the morphology and healing of the model can be evaluated by Micro-CT, which provides an animal model for the basic research on the diagnosis and treatment of bone defect.

Key words: rat, tibial fracture, animal models, fracture healing, micro-CT

摘要： 目的 建立采用克氏针骨皮质固定法制备大鼠胫骨骨缺损模型,并采用影像学评价。 方法 将 30 只 SD 大鼠分为假手术组、固定组和未固定组 3 组,每组 10 只,固定组和未固定组在胫骨中段用电锯造成骨缺损,缺损宽度约为 2 mm,深度约为 2 mm,固定组用克氏针在骨皮质固定(未固定组不用克氏针) ,假手术组仅暴露胫骨中段。 计算机显微断层扫描(Micro-CT) 、苏木精-伊红染色( HE 染色) 、马松染色( Masson’ s trichrome staining) 、番红固绿染色( Safranin O / Fast green staining) 、 甲苯胺蓝染色 ( Toluidine blue staining) 评价骨缺损模型及愈合情 况。 结 果 术后 3 d 固定组造模成功率为 100%,未固定组成功率为 60% ( P < 0. 05) 。 术后 3 d Micro-CT 测量骨缺损高度为(1. 65±0. 21) mm,宽度为(1. 99±0. 15) mm,14 d 测量骨缺损宽度为(1. 38±0. 17) mm,高度为( 1. 77±0. 16) mm,缺损范围逐渐缩小。 Micro-CT 结果和组织切片结果一致。 结论 成功利用克氏针骨皮质固定法制备缺损模型,MicroCT 可用于评价模型形态及愈合,为骨缺损诊疗基础研究提供动物模型建立及评价方法。

关键词: 大鼠, 胫骨骨折, 动物模型, 骨折愈合, Micro-CT