Surgeon Ergonomics of Lateral Lumbar Interbody Fusion Across Four Patient Positions: A Proof-of-Concept Simulation Study Using Motion Capture and Electromyography
Philip K. Louie, Anthony Y. Jeong, Renzo A. Laynes, Mir Amaan Ali, Kento Yamanouchi, Kenneth T. Nguyen, Jean-Christophe Leveque, Venu M. Nemani, Aiyush BansalStudy Design
Proof-of-concept simulation-based biomechanical pilot study.
Objectives
To compare surgeon posture and muscle activity across four lateral lumbar interbody fusion (LLIF) positions and rank them by overall ergonomic burden.
Methods
Five right-handed spine surgeons (case volumes 15 to 500 or more) each simulated a single-level LLIF on a synthetic model in four positions, three using direct vision (lateral decubitus, prone seated, prone lateral) and one using a camera and monitor (prone camera). Whole-body motion capture and surface EMG were recorded simultaneously, analyzed by surgical phase, and summarized per surgeon.
Results
Neck-flexion intensity was greatest in lateral decubitus and lower in every prone position, with the same ranking in all five surgeons (exact Friedman p=3.0e-06, Kendall W=1.00). Arm elevation was highest in prone seated. Across four summaries of posture and muscle activity, prone camera was the most favorable position in every surgeon, while the others reordered by measure. All positions scored medium-to-high risk. No two-position comparison reached adjusted significance, as expected at this sample size.
Conclusions
Patient position in LLIF does not appear to change patient outcome, but it changes what the operation costs the surgeon. Lateral decubitus loaded the neck in every surgeon regardless of case volume or preference, prone seated loaded the shoulder, and prone camera was most favorable overall . Surgeons can reduce their exposure through position and setup, and ergonomics offers an objective way to compare setups when patient outcomes cannot separate them. These are proof-of-concept findings in five surgeons and require confirmation in a larger sample.