Individual navigation templates for the installation of pedicle screws in the cervical spine

Abstract

The experiment was performed on 2 samples of the pig's cervical spine. 12 transpedicular screws were implanted using navigation templates. The safety and accuracy of installation of screws were evaluated by analyzing the results of computed tomography. 12 screws had a level of implantation safety of 0 degree – the screw was completely inside the bone structures of the vertebra. The accuracy of the implanted screws was evaluated by determining the degree of deviation of the obtained screw trajectory from the planned one. The resulting accuracy of the installed screws is 91 % and corresponds to class 1. At standard deviation, there were no significant differences in the axial and sagittal angles between the planned installation and the actual trajectory of the screw for the subaxial cervical spine on the left and right. There were no significant differences in the standard deviation in the axial projection at the points of entry and intended exit of the screw. Statistical analysis did not reveal significant differences between planned and actual results (P > 0.05).