Zhang Wei, Liang Huan, Huang Zhi-Chao, Zhao Rui-Feng, Zhong Hong-Gang, Chen Wei-Heng, Ma Yu-Feng
Osteopathology Center, the Third Affiliated Hospital of Beijing University of Chinese Medicine, Beijing 100029, China.
Graduate School of Beijing University of Traditional Chinese Medicine, Beijing 100029, China.
Zhongguo Gu Shang. 2023 Jul 25;36(7):662-8. doi: 10.12200/j.issn.1003-0034.2023.07.013.
To explore the effect of a modified three-point bending fracture device for establishing a rabbit model of closed tibial fracture.
The model of closed tibial fracture was established in 40 6-month-old male New Zealand white rabbits with a body weight of 2.5 to 3.0 kg, and the model was verified at 6 weeks after operation. Five rabbits underwent pre modeling without temporary external fixation before modeling, and then were fractured with a modified three-point bending fracture device;35 rabbits underwent formal modeling. Before modeling, needles were inserted, and splints were fixed externally, and then the fracture was performed with a modified three-point bending fracture device. The fracture model and healing process were evaluated by imaging and histopathology at 2 hours, 4 weeks, and 6 weeks after operation.
Two hours after modeling, the prefabricated module showed oblique fracture in varying degrees and the broken end shifted significantly;Except for 1 comminuted fracture, 2 curved butterfly fractures and 2 without obvious fracture line, the rest were simple transverse and oblique fractures without obvious displacement in formal modeling group. According to the judgment criteria, the success rate of the model was 85.71%. Four weeks after modeling, the fixed needle and splint of the experimental rabbits were in good position, the fracture alignment was good, the fracture line was blurred, many continuous callus growths could be seen around the fracture end, and the callus density was high. Six weeks after modeling, many thick new bone trabeculae at the fracture, marginal osteoblasts attached, and a small number of macrophages were seen under the microscope. The intramembrane osteogenesis area was in the preparation bone stage, the medullary cavity at the fracture had been partially reopened, the callus was in the absorption plastic stage, and many osteoclasts were visible. The X-ray showed that the fracture line almost disappeared, part of the medullary cavity had been opened, the external callus was reduced around, the callus was in the plastic stage, and the bone cortex was continuous. It suggests that the fracture model showed secondary healing.
The improved three-point bending fracture device can establish a stable rabbit model of closed tibial fracture, and the operation is simple, which meets the requirements of closed fracture model in basic research related to fracture healing.
探讨改良三点弯曲骨折装置建立兔闭合性胫骨骨折模型的效果。
选取40只6月龄、体重2.5～3.0 kg的雄性新西兰白兔建立闭合性胫骨骨折模型，并于术后6周进行模型验证。5只兔子在建模前未进行临时外固定，直接用改良三点弯曲骨折装置造成骨折；35只兔子进行正式建模。建模前先插入针，外部固定夹板，然后用改良三点弯曲骨折装置造成骨折。于术后2小时、4周和6周通过影像学和组织病理学评估骨折模型及愈合过程。
建模后2小时，预制组出现不同程度的斜形骨折，断端明显移位；正式建模组除1例粉碎性骨折、2例弯曲蝶形骨折和2例无明显骨折线外，其余均为简单横形和斜形骨折，无明显移位。按判定标准，模型成功率为85.71%。建模后4周，实验兔的固定针和夹板位置良好，骨折对线良好，骨折线模糊，骨折端周围可见许多连续的骨痂生长，骨痂密度高。建模后6周，骨折处可见许多粗大的新生骨小梁，边缘有成骨细胞附着，显微镜下可见少量巨噬细胞。膜内成骨区处于制备骨阶段，骨折处髓腔已部分再通，骨痂处于吸收塑形阶段，可见许多破骨细胞。X线显示骨折线几乎消失，部分髓腔已开放，周围外骨痂减少，骨痂处于塑形阶段，骨皮质连续。提示骨折模型呈二期愈合。
改良三点弯曲骨折装置可建立稳定的兔闭合性胫骨骨折模型，且操作简单，满足骨折愈合相关基础研究中闭合骨折模型的要求。
