[Comparison of two methods for preparing knee osteochondral injury models in mice].

To observe the effect of using tungsten drills to prepare mouse knee osteochondral injury model by comparing with the needle modeling method, in order to provide an appropriate animal modeling method for osteochondral injury research.A total of 75 two-month-old male C57BL/6 mice were randomly divided into 3 groups ( n=25). Mice in groups A and B were used to prepare the right knee osteochondral injury models by using needles and tungsten drills, respectively; group C was sham-operation group. The general condition of the mice was observed after operation. The samples were taken at 1 day and 1, 2, 4, and 8 weeks after modeling, and HE staining was performed. The depth, width, and cross-sectional area of the injury site at 1 day in groups A and B were measured, and the percentage of the injury depth to the thickness of the articular cartilage (depth/thickness) was calculated. Toluidine blue staining and immunohistochemical staining for collagen type Ⅱ were performed at 8 weeks, and the International Cartilage Research Society (ICRS) score was used to evaluate the osteochondral healing in groups A and B.All mice survived to the completion of the experiment. HE staining showed that group C had normal cartilage morphology. At 1 day after modeling, the injury in group A only broke through the cartilage layer and reached the subchondral bone without entering the bone marrow cavity; the injury in group B reached the bone marrow cavity. The depth, width, cross-sectional area, and depth/thickness of the injury in group A were significantly lower than those in group B ( P<0.05). At 1, 2, 4, and 8 weeks after modeling, there was no obvious tissue filling in the injured part of group A, and no toluidine blue staining and expression of collagen type Ⅱ were observed at 8 weeks; while the injured part of group B was gradually filled with tissue, the toluidine blue staining and the expression of collagen type Ⅱ were seen at 8 weeks. At 8 weeks, the ICRS score of group A was 8.2±1.3, which was lower than that of group B (13.6±0.9), showing significant difference ( t=-7.637, P=0.000).The tungsten drills can break through the subchondral bone layer and enter the bone marrow cavity, and the injury can heal spontaneously. Compared with the needle modeling method, it is a better method for modeling knee osteochondral injury in mice.通过与注射器针头造模方法比较，观察钨钢麻花钻头制备小鼠膝关节骨软骨损伤模型效果，以期为骨软骨损伤研究提供合适的动物模型制备方法。.75 只 2 月龄雄性 C57BL/6 小鼠随机分为 3 组（ n=25），A 组采用注射器针头、B 组采用钨钢麻花钻头制备右后肢膝关节骨软骨损伤模型，C 组为假手术组。术后观察小鼠一般情况，分别于造模后 1 d 及 1、2、4、8 周取材，常规行 HE 染色观察，并测量 A、B 组 1 d 时损伤部位深度、宽度、横截面积，计算损伤部位深度占关节软骨厚度的百分比（深度/厚度）；取 8 周切片分别行甲苯胺蓝染色以及Ⅱ型胶原免疫组织化学染色，采用国际软骨研究协会（ICRS）评分标准评价 A、B 组骨软骨损伤愈合情况。.所有小鼠均存活至实验完成。HE 染色示 C 组为正常软骨形态。造模后 1 d，A 组损伤仅突破软骨层达软骨下骨，未进入骨髓腔；B 组损伤已达骨髓腔。A 组损伤部位深度、宽度、横截面积和深度/厚度均小于 B 组（ P<0.05）。造模后 1、2、4、8 周，A 组损伤部位均未见明显组织填充，至 8 周时未见甲苯胺蓝着色以及Ⅱ型胶原表达；而 B 组损伤部位随时间延长已逐渐被组织填充，8 周时见甲苯胺蓝着色及Ⅱ型胶原表达。8 周时 A 组 ICRS 评分为（8.2±1.3）分，低于 B 组的（13.6±0.9）分，差异有统计学意义（ t=−7.637， P=0.000）。.相对于注射器针头造模方法，钨钢麻花钻头可突破软骨下骨进入骨髓腔，软骨损伤能自发愈合，是一种更好的小鼠膝关节骨软骨损伤模型制备方法。.