胸腰椎爆裂性骨折模型的快速制备

目的探讨快速制备胸腰椎爆裂性骨折模型的方法。方法取20个猪胸腰段3联体标本,上下椎体行环氧树脂包埋,中间椎体中部一侧前1/3、2/3处用直径为3.2 mm的钻头钻孔,平行对穿椎体,造成中间椎体的有限性损伤,游标卡尺测量骨折前L1椎体前缘高度,记为完整椎体的高度(HInt)。将9 kg不锈钢锤置于高0.5 m高处,沿引导杆垂直撞击标本,若L1椎体无骨折迹象则升至0.6 m的高度,若有骨折迹象则将钢锤降至0.4 m,在0.5 m的基础上以0.1 m递增或递减进行多次撞击,直至L1形成爆裂性骨折,记录撞击总能量,撞击总能量E=mgh1+mgh2+…+mghn。爆裂性骨折形成后再次测量L1椎体的前缘高度,记为HFr并对所形成的爆裂性骨折模型行影像学检查。结果骨折前椎体前缘高度为(27.405±1.453)mm,骨折后椎体前缘高度为(17.784±1.362)mm,骨折前后差异有统计学意义(P0.05)。当撞击高度为0.5 m时有4个爆裂性骨折模型形成,当累计撞击高度为0.9 m时有13个爆裂性骨折模型形成;当累计撞击高度为1.3 m时有3个爆裂性骨折模型形成。累计平均撞击高度为0.865 m;累计平均撞击能量为76.313 J。影像学显示所有标本椎体均造成典型爆裂性骨折。结论采用上下椎体包埋,中间椎体有限损伤,多次撞击实验可以制作典型胸腰椎爆裂性骨折的模型。

Rapid preparation of model for thoracolumbar burst fracture

Objective To investigate the method of rapid preparation of thoracolumbar burst fracture. Methods To produce 20 thoracolumbar 3-conjoined porcine specimens, the upper and lower vertebrae was resin-embeded by epoxy,and the middle vertebrae was drilled a hole by drill (3.2 mm) respectively on one side of the middle 1/3, 2/3 to create limited damage. L₁ anterior border height was measured by vernier caliper (H_Int). The 9 kg stainless steel hammer was placed at 0.5 m. Then the specimen was impacted along the vertical guide rod. If the middle vertebrae had no signs of fracture, the stainless steel hammer was promoted by 0.1 m at the basis of 0.5 m. If the middle vertebrae had signs of fracture, the stainless steel hammer was descended by 0.1 m at the basis of 0.5 m. When the middle vertebral body formated the burst fracture, the total impact energy was recorded. After middle vertebral body formated the burst fracture, L₁ anterior border height was measured again (H_Fr). Then all the models were examined by radiographic methods. Results Before fracture the height of anterior border was (27.405± 1.453) mm, and after the fracture, the height of anterior border was (17.784±1.362) mm, there has significant difference bewteen before and after fracture (P< 0.05). When the impact height was 0.5 m, 4 burst fracture model were observed. When the cumulative impact height was 0.9 m, 13 burst fracture model were observed. When the cumulative impact height was 1.3 m, 3 burst fracture model were observed. The cumulative average impact height was 0.865 m, and the cumulative average impact energy was 76.313 J. The models of burst fracture was confirmed by radiological examination. Conclusion A typical thoracolumbar burst fracture model can be made when the middle vertebrae is limitedly injured, the upper/lower vertebrae resin-embed and impact is given for several times.