椎骨胸腰节段压缩骨折的有限元分析研究

目的利用有限元方法建立椎体前缘不同压缩状态模型，并分析椎体前缘压缩程度与邻椎终板应力的相关性。方法基于正常成年人志愿者的胸腰段CT 数据，导入Mimics，经图像分割、修补及三维网格化获取胸腰椎T11～L1３个节段数据，网格赋材质属性后导入ABAQUS 软件，获取逼真的三维有限元模型。对模型进行生理载荷加载，验证正常模型的有效性。将L1模型底部全自由度固定，在T11模型上方施加前屈、后伸及轴向压缩载荷，分别将椎体前沿压缩至90%、80%、70% ...... 10% 9个状态，提取T11下终板及L1上终板的MISES应力，获得了压缩状态与邻近终板应力关系曲线。结果该模型高度逼真，能真实反映实际受力状态；T11椎体下位终板和L1椎体上位终板的应力值与T12椎体（研究对象）前沿的压缩程度正相关。结论应力增加可能导致终板骨折可能性增加，进而增大相邻椎体的骨折风险，有限元分析结果能够为临床实践提供依据。

Finite element analysis of compression fracture of thoracolumbar spine

Objective To establish models of different vertebral compression, and to analyze the correlation between vertebral compression and adjacent vertebral endplate stress with finite element analysis. Methods CT thoracolumbar data of normal adult volunteers were imported into MIMICS/3-matic. The data of three thoracolumbar segments (T11-L1) were obtained by segmentation, repair and three-dimensional grid, and imported to ABAQUS after assignment of grid material properties, and then the realistic three dimensional finite element models were obtained. The model was loaded with physiological load, and the validity of the normal model was verified. The total freedom at the bottom of the L1 model was fixed, and the T11 model was applied with flexion, extension and axial compressive load. With the frontier compression of vertebral body to 90%, 80%, 70% ...10% nine states, the MISES stresses of T11 inferior endplate and L1 superior endplate were extracted, the relationship curve between the compression state and adiacent endplate stresses was obtained. Results The results showed that the model was highly realistic and could reflect the actual stress state. The stress values of the lower endplate of T11 vertebral body and the upper endplate of L1 vertebral body were positively correlated with the anterior compression of T12 vertebral body. Conclusions Increased stress may lead to increased likelihood of endplate fracture, thereby increases the risk of adjacent vertebral fractures. Finite element analysis can provide the basis for clinical practice.