Does operative start time influence the accuracy of cervical pedicle screw insertion using preoperative CT-based navigation?

PURPOSE: This study investigated whether procedures performed outside regular working hours affected the precision of cervical pedicle screw (CPS) insertion under computed tomography (CT)-based navigation guidance.

SUMMARY OF

BACKGROUND

Although navigation systems improve insertion accuracy, the impact of operative start time on CPS placement remains unclear.

METHODS

We retrospectively analyzed 138 patients (561 screws) who underwent CPS insertion using preoperative CT-based navigation between 2016 and 2022. CPS placement accuracy was assessed by postoperative CT and classified according to the extent of cortical perforation. Procedures initiated between 5:16 PM to 8:29 AM defined as after-hours. Multivariable generalized linear mixed models were constructed to identify factors associated with screw perforation.

RESULTS

Clinically significant perforation occurred in 10.0% (12/120) of screws placed during after-hours procedures and in 7.5% (33/441) of regular-hours placements. Multivariate analysis demonstrated that while screw placement in the middle cervical spine (C3-5) was independently associated with perforation (odds ratio: 3.31, p <0.01), operative start time was not (odds ratio: 1.07, p = 0.90).

CONCLUSIONS

Operative start time was not independently associated with CPS placement accuracy in this cohort. Due to the wide confidence intervals, these exploratory findings do not establish the non-inferiority or equivalent safety of after-hours surgery. Further large-scale studies are warranted.