Off-Hours Robotic-Assisted Spine Instrumentation in a Teaching Hospital: Feasibility Under Increased Emergency and Workflow Burden.

Background/Objectives: Robotic-assisted spine instrumentation is resource-intensive and may be challenging during off-hours emergency care. This study evaluated its operational feasibility and technical reliability in a teaching hospital. Methods: We performed an exploratory post hoc secondary analysis of 146 consecutive robotic-assisted spine instrumentation procedures comprising 1006 pedicle or sacral-alar-iliac screws. Off-hours surgery was defined as night and/or weekend surgery. The primary outcome was screw-level Gertzbein-Robbins (GR) accuracy. Secondary outcomes included workflow, perioperative, and 30-day clinical measures. Because all off-hours procedures were emergencies, an additional sensitivity analysis compared off-hours with regular-hours emergency procedures. Results: Sixteen procedures comprising 150 screws were performed off-hours. In the unadjusted primary comparison, off-hours cases had greater trauma and emergency burden, more frequent repeat imaging or re-registration, higher intensive care unit (ICU) utilization, and longer hospitalization. GR A/B accuracy was 96.0% off-hours and 98.2% during regular hours, while GR C-E rates were 4.0% and 1.8%, respectively. Severe deviations were uncommon, and no screw-related postoperative neurological deficit occurred. In the emergency-only analysis, GR A/B accuracy was 96.0% off-hours and 96.7% during regular-hours emergency surgery, while several perioperative differences were attenuated. Conclusions: Robotic-assisted spine instrumentation remained operationally feasible during off-hours emergency surgery, with high screw accuracy and few severe deviations. However, the small and highly selected off-hours subgroup and marked case-mix differences preclude conclusions regarding equivalence, comparative safety, or an independent effect of surgical timing. These findings should be considered hypothesis-generating.