Finite element analysis of biomechanical performance of a novel double-screw technique in lumbar revision of the original fixed segment

• Both cortical bone trajectory (CBT) and modified cortical bone trajectory (MCBT) screw placement techniques significantly improve the mechanical stability of the fixed segment in lumbar revision surgery, with MCBT showing superior overall performance. • The novel double-screw technique preserves the original internal fixation, reducing surgical trauma and avoiding risks associated with traditional revision methods. • MCBT demonstrated greater reductions in intervertebral disc stress and vertebral body stress compared to CBT, particularly under extension and lateral bending. • Finite element analysis provides a robust framework for evaluating the biomechanical performance of novel spinal fixation techniques, supporting clinical decision-making.