MECHANICAL BEHAVIOR OF THORACOLUMBAR CORONAL SPLIT FRACTURES: FINITE ELEMENT ANALYSIS

ABSTRACT Objective To analyze the behavior of thoracolumbar fractures of the coronal split type using the finite element method. Methods Two comparative studies were conducted through simulation of coronal split fractures in a finite model in which the first lumbar vertebra (L1) was considered to be fractured. In the first case, the fracture line was considered to have occurred in the middle of the vertebral body (50%), while in the second model, the fracture line occurred in the anterior quarter of the vertebral body (25%). The maximum von Mises stress values were compared, as well as the axial displacement between fragments of the fractured vertebra. Results The stress levels found for the fracture located at half of the vertebral body were 43% higher (264.88 MPa x 151.16 MPa) than those for the fracture located at the anterior 25% of the vertebra, and the axial displacement of the 50% fractured body was also greater (1.19 mm x 1.10 mm). Conclusions Coronal split fractures located in the anterior quarter of the vertebral body incurred less stress and displacements and are more amenable to conservative treatment than 50% fractures occurring in the middle of the vertebral body. Level of Evidence III; Experimental study.摘要 研究目的：采用有限元法（Finite Element Method）分析冠状劈裂型胸腰椎骨折的力学行为。 研究方法：以第一腰椎（L1）骨折为建模对象，通过在有限元模型中模拟冠状劈裂骨折开展两组对照研究。第一组模型中，骨折线位于椎体中部（50%位置）；第二组模型中，骨折线位于椎体前1/4区域（25%位置）。本研究对比了两组的最大冯·米塞斯（von Mises）应力值，以及骨折椎体各骨块间的轴向位移。 研究结果：椎体中部骨折组的应力水平较椎体前25%骨折组高43%（264.88 MPa × 151.16 MPa），且50%骨折椎体的轴向位移亦更大（1.19 mm × 1.10 mm）。 研究结论：椎体前1/4区域的冠状劈裂骨折所承受的应力与位移均更小，相较于椎体中部的50%骨折，该类骨折更适合采用保守治疗方案。 证据等级：Ⅲ级；实验性研究。