Internal fixation is a prevalent surgical method for thoracolumbar burst fracture stabilization. It helps approximately 10-20% of all thoracolumbar spine fractures, which account for about 90% of all spine fractures. Prediction of the range of motion is a challenging task for surgeons which is beneficial to be evaluated before surgeries. Finite element method (FEM) is a powerful tool in predicting and analyzing the outcomes of surgical operations. This study aimed at exploring the existing differences between the range of motion of a patient model with a deformity in segment L2-L4 (PM) and a post-operation model (POM), using FEM for a corpectomy surgery, under flexion and extension modes of loading.