一种新型颈椎骨折错位的大鼠原发性脊髓损伤模型

An innovative primary spinal cord injury model of rat cervical spinal dislocation fracture

目的模拟临床建立一种大鼠颈椎骨折错位的原发性脊髓损伤模型。方法依据大鼠颈椎解剖特点,自行研制的头侧椎夹固定C3和C4,连接固定于大鼠立体定位架上。尾侧椎夹固定C5和C6并连接到材料试验机,以定速向背侧错位后返回原位,产生C4-5骨折错位和脊髓损伤。按上述方法在8只雄性大鼠C4-5产生骨折错位1.90 mm,错位速度2 mm/s。损伤后立刻行心脏灌注固定,HE染色分析脊髓出血量。结果 C4-5椎间盘均在C4下终板处断裂,椎间盘破坏的错位位移为（1.00±0.17）mm,最大力为（12.7±5.1）N。肉眼观察到脊髓均有出血,脊髓背侧有两条对称的淤血带,或者色泽较深的出血点;HE染色进一步显示脊髓C4和C5节段的出血主要集中在灰质,而白质有分散的出血点,且背侧较腹侧多,脊髓总出血量为（2.46×10-3±1.26×10-3）ml。结论该动物模型可以产生颈椎骨折错位和脊髓损伤,是一种新型的与临床相关的原发性脊髓损伤模型。

Objective To develop a clinical relevant primary spinal cord injury（SCI） rat model due to cervical spinal dislocation fracture.Methods A SCI device leading to cervical spinal dislocation fracture was developed based on cervical vertebrae anatomy of SD rats.A rostral clamp connected to a stereotaxic apparatus held C3 and C4 and kept stationary during injury,while a caudal clamp held C5 and C6 and was connected to a material testing machine.The caudal clamp was driven dorsally at a constant speed and returned to the original position,producing C4-5 dislocation fracture and spinal cord injury.The C4~5 dislocation fracture up to 1.90mm at 2mm/s was produced on eight male SD rats using the aforementioned method.The rats were perfused intracardially right after injury.One set of sections from each cord was stained with hematoxylin and eosin.Total hemorrhage in the cord was calculated.Results All C4-5 intervertebral discs were ruptured at C4 inferior endplate with an average of rupture displacement of（1.00±0.17） mm and the maximal force of（12.7±5.1） N.Two symmetrical hemorrhage strips or points were observed on all spinal cords in the experimental group.The hemorrhage was mainly located in the gray matter and scattered in the white matter more dorsally than ventrally.The average of total hemorrhage was（2.46×10-3±1.26×10-3） ml.Conclusions The model can produce cervical vertebrae dislocation fracture and primary spinal cord injury,and is a clinical relevant animal model for SCI study.