<p>Vertebrectomy at the subapical vertebra for severe angular kyphosis creates a critical anterior column defect, which results in incomplete mechanical load transmission and a risk of pedicle rod fracture. This study introduces a novel expandable artificial vertebral body designed to reconstruct the anterior spinal support. The finite element method was used to compare the effects of the artificial vertebral body on the mechanical stability of the spine following subapical vertebrectomy under different simulated torques. In the spine model, stress is concentrated on the screw-rod of the osteotomy site. Under all loading modes, the peak stress and displacement of internal fixation in the reconstructed spine model were substantially lower than those in the model of the spine. Stress distribution analysis along the rod revealed a markedly attenuated stress waveform after the body implantation, with corresponding peak stresses on the rods and screws reduced by up to 90% under static loading conditions. In this study, the expandable artificial vertebral body markedly offloaded stress from the screw-rod fixation, thereby mitigating the risks of rod fracture and enhancing the overall safety and reliability of the spinal fixation constructs.</p> Graphical Abstract <p></p>