| Objective To explore the feasibility of achieving a high dual cortical fixation rate for sacral screws using manual techniques combined with torque measurement, and to determine the optimal depth for dual cortical fixation.Methods Between October 2020 and October 2021, 48 patients who underwent posterior lumbar dynamic fixation were included. All the cases were randomly divided into the dual cortical 180° group, 360° group, and 720° group based on screw insertion depth . A comparative analysis was conducted among the groups regarding sacral screw insertion torque, dual cortical fixation rate, and screw loosening occurrences.Results The average follow-up time for all cases was (13.5±5.1) months (range: 12-21 months). The dual cortical fixation rates were 66.67%, 94.12% and 93.75% in the dual cortical 180°, 360°, and 720° groups, respectively. The differences in dual cortical fixation rates were statistically significant between the dual cortical 180° group and the 360° group as well as the 720° group (P<0.05); there were no statistically significant differences in dual cortical fixation rates between the 360° group and the 720° group (P>0.05). The rates of sacral screw loosening were 23.33%, 5.88%, and 3.13% in the dual cortical 180°, 360°, and 720° groups, respectively. The differences in screw loosening rates were statistically significant between the dual cortical 180° group and the 360° group as well as the 720° group (P<0.05); there were no statistically significant differences in screw loosening rates between the 360° group and the 720° group (P>0.05).Conclusion The manual technique combined with the torque measurement method is a safe, effective, and stable approach for achieving dual cortical fixation of the sacral bone. |
