Department of Spine Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, China.
Chin Med J (Engl). 2013;126(15):2852-8.
Thoracolumbar burst fracture is a common clinical injury, and the fracture mechanism is still controversial. The aim of this research was to study the formation of intracanal fracture fragments in thoracolumbar burst fractures and to provide information for the prevention of thoracolumbar bursts fractures and reduction of damage to the nervous system.
A nonlinear three-dimensional finite element model of T11-3 segments was established, and the injury processes of thoracolumbar bursts were simulated. The intact finite element model and the finite element model after the superior articular were impacted by 100 J of energy in different directions. The distribution and variation of stress in the superior posterior region of the L1 vertebral body were analyzed. Abaqus 6.9 explicit dynamic solver was used as finite element software in calculations.
A three-dimensional nonlinear finite element model of the thoracolumbar spine was created. In the intact model, stress was concentrated in the superior posterior region of the L1 vertebral body. The stress peak was a maximum for the extension impact load and a minimum for the flexion impact load. The stress peak and contact force in the facet joint had close correlation with time. The stress peak disappeared after excision of the superior articular process.
The three-dimensional nonlinear finite element model was suitable for dynamic analysis. The contact force in the facet joint, which can be transferred to the superior posterior vertebral body, may explain the spinal canal fragment in thoracolumbar burst fractures.
胸腰椎爆裂骨折是一种常见的临床损伤，其骨折机制仍存在争议。本研究旨在探讨胸腰椎爆裂骨折椎管内骨折块的形成机制，为预防胸腰椎爆裂骨折及减少对神经系统的损伤提供依据。
建立 T11-3 节段的非线性三维有限元模型，模拟胸腰椎爆裂骨折的损伤过程。对完整有限元模型及在上关节突受到 100J 不同方向能量冲击的有限元模型进行分析，观察上关节突后上方区域的应力分布和变化。计算采用 Abaqus 6.9 显式动力学求解器作为有限元软件。
成功建立了胸腰椎脊柱的三维非线性有限元模型。在完整模型中，应力集中于 L1 椎体上关节突后上方区域。在屈伸冲击载荷作用下，应力峰值最大，在压缩冲击载荷作用下，应力峰值最小。小关节面的接触力与时间密切相关。切除上关节突后，应力峰值消失。
三维非线性有限元模型适用于动态分析。关节突关节面传递至上关节突后上方椎体的接触力，可解释胸腰椎爆裂骨折椎管内骨折块的形成机制。
