Mechanical analysis of a bone cement-augmented cortical bone trajectory screw versus a new variable-diameter all-cortical bone screw

• Bone cement-augmented cortical bone trajectory (CBT) screws demonstrated superior axial pullout force compared to both modified variable-diameter all-cortical bone screws and un-augmented CBT screws. • In terms of screw stability under inferior loading, the augmented CBT group showed the highest load-displacement ratio, followed by the modified group, with the un-augmented group lowest. • Vertebral range of motion was reduced in both augmented and modified CBT groups compared to un-augmented, but no significant difference was found between augmented and modified groups. • The bone cement-augmented CBT technique may be a more appropriate choice for internal fixation in osteoporotic patients, offering better biomechanical performance than the novel variable-diameter screw.