摘要
背景：对于不稳定的胸腰段骨折选择合适的内固定方式至关重要。目的：建立胸腰段爆裂骨折以及不同方式内固定有限元模型,进行不同方向加载后比较不同固定方式的生物力学特性。设计、时间及地点：对比观察,于2008/08-10在同济大学力学实验室完成。材料：采用德国西门子公司螺旋CT（64排）扫描一成年健康男性志愿者的T11-L1节段,间隔0.6mm。采用布尔操作,去除T12椎体下半部分,保留椎体的后部结构,建立胸腰段爆裂骨折的有限元模型。方法：试验分为5组,模型1为后路4钉2棒固定模型,模型2为后路5钉2棒（单侧伤椎固定）模型,模型3为后路6钉2棒（双伤病椎固定）模型,模型4为前路侧前方双棒固定模型,模型5为前后路联合固定模型。分别对于各模型进行前曲、后伸、左侧曲以及右侧旋转的加载,比较各模型的生物力学特性。主要观察指标：试验模型加载额定载荷后不同运动方向的VonMises应力以及位移。结果：各种模型的运动状态中,应力从钉尖部至钉棒连接处逐渐增大,近钉棒连接处应力最大;近端螺钉受到的应力大于远端螺钉受到的应力。在试验的每种运动状态中,模型1的螺钉应力高于模型2,3,高于模型5（P〈0.01）。模型5的稳定性最好;模型1各个方向位移最大,稳定性最差。结论：建立了不同固定方式的T12椎体爆裂骨折固定模型,验证了在胸腰段骨折内固定治疗中,应用后路短节段固定结合伤椎固定及经椎弓根植骨治疗胸腰段骨折比单纯后路短节段固定具有更良好的生物力学特性。
BACKGROUND： A selection of treatment for thoracolumbar fracture is very important. OBJECTIVE： To develop and validate three-dimensional finite element models of human thoracolumbar fracture using varying fixation methods, and to compare biomechanical characteristics of fixation method. DESIGN TIME AND SETTING： A contrast observation was performed at the Mechanical Experiment Center of Tongji University from August to October 2008. MATERIALS： 64-slice spiral CT （Siemens, Germany） was used to scan T11-L1 segments of an adult male, and the slice thickness was 0.6 mm. based on Boolean operation, the lower half of T12 segment was resected, and the structure of posterior part was reserved to establish finite element model of thoracolumbar fracture. METHODS： There were five groups in this study, including 4 pedicle screws ＋ 2 rods （group 1）, 5 pedicle screws ＋ 2 rods at one side （group 2）, 6 pedicle screws ＋ 2 rods at both sides （group 3）, anterior fixation （group 4）, and anterior plus posterior fixation （group 5）. Forces of axial compressive, anterior bending, posterior extension, left bending, and right rotation were loaded to compare the biochemical characteristics. MAIN OUTCOM MEASURES： vonMises stress and displacement at different directions. RESULTS： The stresses of all the fixation screws increased from the anterior part to posterior part in all movement tests, and the strongest stress was measured in the joint position. The stress of proximal screw was stronger than that of the distal screw. Additionally, the stress in group 1 was significantly stronger than in groups 2, 3, and 5 （P〈 0.01）. The group 5 was the most stable, but the group 1 was the poorest. CONCLUSION： T12 bursting fracture models were established using varying fixation methods, and the results verified that short segment plus fracture vertebral segmental fixation has more superior biomechanics.
出处
《中国组织工程研究与临床康复》
CAS
CSCD
北大核心
2009年第52期10269-10273,共5页
Journal of Clinical Rehabilitative Tissue Engineering Research
