| 摘要: |
| 目的 建立并评价小鼠股骨骨折合并坐骨神经损伤的标准化动物模型。方法 将96只雄性C57BL/6J小鼠随机分为两组：股骨骨折合并坐骨神经损伤组（48只）和股骨骨折组（48只）。股骨骨折合并坐骨神经损伤组小鼠通过止血钳钳夹致左侧坐骨神经损伤，并于同侧进行股骨开放性骨折联合髓内针固定，制作小鼠股骨骨折合并坐骨神经损伤模型；股骨骨折组小鼠仅游离左侧坐骨神经，不做钳夹处理，同时进行左侧股骨开放性骨折联合髓内针固定。术后仔细观察两组小鼠的行为学变化。于术后第3、5、7、10、14、18天取两组各36只小鼠的左侧坐骨神经，每个时间点每组6只，通过免疫组织化学染色观察坐骨神经的组织学变化。于术后第7、14、21、28天通过股骨X线片、Micro-CT、H-E染色及番红固绿染色分析骨折愈合情况。结果 成功建立小鼠股骨骨折合并坐骨神经损伤模型，行为学观察与评估发现术后第14天股骨骨折合并坐骨神经损伤组小鼠步态基本恢复正常；坐骨神经免疫组织化学染色显示，术后第14天股骨骨折合并坐骨神经损伤组小鼠的坐骨神经纤维连续性基本恢复；Micro-CT检查显示在各时间点，股骨骨折合并坐骨神经损伤组的骨体积均小于股骨骨折组（P均＜0.01），骨体积百分比也均低于股骨骨折组（P均＜0.01）。骨切片组织形态学结果显示，股骨骨折合并坐骨神经损伤组小鼠术后第7天骨折断端几乎不存在骨痂；术后第14天出现少量软骨痂，主要由未分化的间充质干细胞构成；术后第21天软骨痂开始钙化，骨痂中存在部分肥大的软骨细胞；术后第28天骨折断端有新生骨形成，含有大量肥大的软骨细胞、成骨细胞与骨细胞。结论 小鼠股骨骨折合并坐骨神经损伤模型构建成功，该模型愈合过程良好，并较单纯股骨骨折的愈合有所延迟，可较好地模拟临床骨折合并周围神经损伤后的骨修复及愈合过程。 |
| 关键词: 股骨骨折 坐骨神经损伤 动物模型 骨折愈合 |
| DOI：10.16781/j.CN31-2187/R.20220703 |
| 投稿时间：2022-09-02修订日期：2022-12-22 |
| 基金项目:国家自然科学基金（81702666）. |
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| Construction and evaluation of a standardized animal model of femoral fracture combined with sciatic nerve injury in mice |
| DING Yun1△,SUI Jun-hao1△,HOU Yi-jin1,2,ZHANG Hao1* |
(1. Department of Orthopaedics Trauma, The First Affiliated Hospital of Naval Medical University (Second Military Medical University), Shanghai 200433, China;
2. Institute of Biomedical Engineering, School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
△Co-first authors.
* Corresponding author) |
| Abstract: |
| Objective To establish and evaluate a standardized animal model of femoral fracture combined with sciatic nerve injury in mice. Methods A total of 96 male C57BL/6J mice were randomly divided into 2 groups: femoral fracture combined with sciatic nerve injury group (n＝48) and femoral fracture group (n＝48). The left sciatic nerves were crushed by hemostatic forceps, and the ipsilateral femurs were cut and fixed with intramedullary nails in the bone marrow. And then, the mouse model of femoral fracture combined with sciatic nerve injury was established in femoral fracture combined with sciatic nerve injury group. Mice in the femoral fracture group underwent fracture of the left femurs by intramedullary nails fixation, and the left sciatic nerves were dissociated, but not clamped. Behavioral observation of postoperative mice was performed in both groups. The left sciatic nerves of mice were collected in both groups (36 mice each) on the 3rd, 5th, 7th, 10th, 14th and 18th d after operation, with 6 mice in each group at each time point, and the histological changes of the sciatic nerves were observed by immunohistochemical staining. On the 7th, 14th, 21st and 28th d after operation, the fracture healing was analyzed by femoral X-ray radiographs, micro-CT, hematoxylin-eosin staining and safranine-fast green staining. Results A mouse model of femoral fracture combined with sciatic nerve injury was successfully established. Behavioral observation and assessment revealed that the gait of mice in the femoral fracture combined with sciatic nerve injury group basically returned to normal on the 14th d after operation. The immunohistochemical results of sciatic nerves showed that the structural continuity of sciatic nerve fibers was basically recovered in the mice of femoral fracture combined with sciatic nerve injury group on the 14th d after operation. Micro-CT showed that the bone volumes of femoral fracture combined with sciatic nerve injury group were significantly lower than those of femoral fracture group at all time points (all P＜0.01), and so were the bone volume/tissue volume (all P＜0.01). The histomorphological results of bone sections showed that on the 7th d calluses almost disappeared at the fracture site; however, a small amount of cartilage calluses appeared on the 14th d, which were mainly composed of undifferentiated mesenchymal stem cells; the cartilage calluses began to calcify on the 21st d, and there were some hypertrophic chondrocytes in the calluses; and on the 28th d, new bone formed, containing a large number of hypertrophic chondrocytes, osteoblasts and osteocytes. Conclusion A mouse model of femoral fracture combined with sciatic nerve injury is successfully constructed, and it has a good healing process and delayed healing compared with that of simple femoral fracture, and can better simulate the bone repair and healing process after clinical fracture combined with peripheral nerve injury. |
| Key words: femoral fractures sciatic nerve injury animal models fracture healing |
