Exoscope-Associated Upper-Limb Rather than Neck Postural Changes During Frontal Sinus Procedures in Bifrontal...

Objectives: Exoscopes decouple viewing from eyepieces and may improve surgeon ergonomics. We compared upper-limb and neck posture during microscope- and exoscope-assisted frontal sinus procedures in bifrontal craniotomies. Methods: Five surgical cases involving five surgeons yielded 12 paired microscope-exoscope posture observations. Eight pairs from four cases met image-selection criteria and underwent angular measurement using ImageJ version 1.54g and RULA-inspired partial postural assessment. Results: Upper arm elevation decreased from 67.3 ± 6.9° under the microscope to 53.5 ± 5.2° under the exoscope (mean change [exoscope minus microscope], -13.8°; 95% CI, -18.0 to -9.6°; p = 0.0001). Elbow angle increased from 36.1 ± 16.6° to 64.4 ± 8.0° (mean change, +28.3°; 95% CI, +15.5 to +41.2°; p = 0.0012). Neck angle showed no clear change (12.3 ± 4.0° vs. 12.9 ± 7.2°; mean change, +0.6°; 95% CI, -4.1 to +5.4°; p = 0.7666). The upper-arm-related score, including shoulder-elevation and abduction points, was lower under the exoscope (p = 0.0156), whereas the forearm score was numerically lower (p = 0.1250). Conclusions: In this exploratory study, exoscope use was associated with reduced upper arm elevation and an increased elbow angle, but no clear change in the neck angle. The predominance and consistency of the upper-limb findings raise the hypothesis that exoscopic visualization may lessen cervicoscapular muscular demand through reduced upper arm and shoulder elevation, even without a measurable change in the static two-dimensional neck angle. Larger studies incorporating three-dimensional motion analysis, muscle activity, fatigue assessment, and clinical outcome measures are needed to determine whether these postural differences translate into reduced musculoskeletal load or injury risk.