Establish The Modles Of Thoracolumbar T12-L1 Spines And Investigate The Thoracolumbar T12-L1 Burst Fracture Mechanism Using Finite Element Method

Backgroud:The thoracolumbar junction is a common site of traumatic injuries, with the thoracolumbar junction injuries contributing to 30–60% of all spinal injuries .Although burst fractures account for only approximately 15% of these injuries , the frequency of neurological deficit in patients with burst fractures can reach up to 50–60% . An adequate comprehension of burst fracture mechanism is therefore useful for effective prevention, mitigation and treatment.Object:Establish the 3D modles of T12-L1 spines to investigate vertebral burst fracture mechanism at the thoracolumbar junction .Method:Obtain the CT data of a healthy adult man by DICOM format during regular health examination which has shown no spinal disease on him . Then the CT images are inputted to the Materialise Mimics and produce 3D surface images of by selecting, preconditioning and remeshing tools, which are then inputted to the ANSYS ICEM CFD10.0 by STL format so as to produce 3D modles, at the same time , the element type and material properties are defined.After the modles are verificated,A rigid ball was directed vertically towards a rigid plate fixed on top of the T12 vertebral body to simulate the axial impact. The stresses of different points of thoracolumbar T12-L1 spines are analyzed to investigate vertebral burst fracture mechanism at the thoracolumbar junction.Result:The T12 vertebra exhibited a vibratory motion upon impact. At its maximum compression, the endplates bulged towards their vertebral bodies. The central parts of the endplates adjacent to the nucleus experienced the highest effective stress, and localized stress concentrates relatively within the central parts of the cancellous bone adjacent to the endplates.Conclusion:This appears to conclude the hypothesis that nucleus material is forced to enter the vertebral body, pressurizing it further and squeezing the fat and marrow contents out of the cancellous bone. When the nucleus material enters the vertebral body faster than fat and marrow being squeezed out, the vertebral body could burst through the anterior and posterior cortical shell. Upon sudden posterior cortex fracture, the transient fragment encroachment could be further into the spinal canal than the final observed locations, as the fragments are retropulsed to the vertebralbody during the bursting process.