A finite element biomechanical study of anterior transpedicular root screw plate fixation

Purpose To compare the biomechanical properties of anterior transpedicular root screw (ATPRS), anterior transpedicular screw (ATPS) and anterior cervical locked-plate (ACLP) in the lower cervical spine by finite element method. Methods We collect CT data of the cervical spine from a healthy 34-year-old adult male volunteer. Use Mimics 10.01 software to build a nonlinear complete model of the lower cervical spine. The model was subjected to 75N axial force and 1.0 N·M to induce various movements. The range of motion (ROM) and stress distribution of each model under different working conditions were compared. Results Compared with the intact model, the ROM in the ACLP, ATPS and ATPRS groups decreased to 0.65, 0.58 and 0.62 during flexion and extension. In terms of titanium mesh graft stress, the ATPS and ATPRS groups had the largest load during extension and the smallest load during flexion. In terms of bone-screw interface stress, the peak stress around screw C7 was higher than that around screw C4 during extension in ACLP, ATPS and ATPRS groups, respectively. Conclusion Biomechanical characteristics of anterior transpedicular root screw system are favorable.