Study On Relationship Between Pressure Distribution And Fracture In The Thoracolumbar Vertebral Boby Using A Three-dimensional Finite Element Model

Objective: This study was designed to investigate the pressure distribution in infra-vertebral boby of the thoracolumbar junction under the different types of compressive loading, to study the relationship between pressure distribution and types of fracture in the thoracolumbar vertebral body , and to analyse the related clinical problems. Method: To develop a detailed, three-dimensional ,finite element model of a human thoracolumbar motion segments(T12-L2). The models were assigned to two groups, axial compressive loading group and anteflexion compressive loading group. With the different load levels (400N, 600N, 800N, 1000N, 1200N),the different type of loading tests were performed. The three layers' cancellous bone in the middle area of the Livertebrae was divided into nine statistical districts. To calculate the average pressure value of the three layers and the nine statistical districts. Statistic was performed. Result: Under both axial loading and antiflexion loading ,the pressure concentration was evident in the statistical districts. Among the three layers, pressure value of the middle layer was minimum, and the value of the upper and the lower ayer was almost equal. The 1 pressure concentration changed dramatically in the posterior part of the vertebral body during axial compressive loading and in the anterior part of the body during anteflexion loading test. Conclusions: The different pressure distribution among the vertebral body of thoracolumbar junction affected directly the fracture type of vertebral body. This changes are highly related to clinical injuries ,the more loss of prevertebral height is, the less canal occlusion, and the less loss of prevertebral height is, the more canal occlusion. In the clinical treatment, the core of recovery of vertebral body is to ensure the recovery of its mechanical structure.