Objective To investigate the effect of fusion on short segment including fractured level (SSIFL) and long segment (LS) transpedicular fixation after acute thoracolumbar junction burst fractures. The 2-year clinical and radiologic follow-up results of the 2 groups also were compared. Methods Seventy-four patients were randomized into one of 2 groups: SSIFL (n = 39) or LS (n = 35). The SSIFL group included one level above and one level below, including the fracture level, whereas the LS group included 2 levels above and 2 levels below, excluding the fracture level, for the transpedicular fixation. Fusion was assessed by technetium 99m-methylendiphosphonate, bone scintigraphy, and single-photon emission computed tomography. The 2-year follow-up results were compared clinically (Oswestry Disability Index and visual analog scale) and radiologically (kyphosis angle, sagittal index, anterior vertebral body height loss) at regular intervals. The clinical scores and radiologic parameters of patients with and without fusion also were compared. Results The number of patients with fusion was significantly greater in the SSIFL group compared with the LS group. There was a significant reduction of the clinical scores of patients who had fusion compared with the fusion-free group; however, there was no radiologically significant difference. Furthermore, there was no significant difference between the SSIFL and LS groups in terms of the 2-year radiologic and clinical follow-up results. Conclusions Fusion occurred sooner and patients experienced earlier clinical recovery in the SSIFL group compared with the LS group.