Assessment of surgeon workload using the NASA-TLX during the early introduction of robot-assisted total knee arthroplasty.

Abstract

Robot-assisted total knee arthroplasty (RA-TKA) improves accuracy, but surgeon workload during early adoption is poorly studied. We quantified workload using the NASA Task Load Index (NASA-TLX) and examined its relation to operative efficiency. Fifty consecutive RA-TKA procedures were performed by one surgeon. After each case, workload was assessed with the NASA-TLX. Outcomes were changes in NASA-TLX scores, operative time learning curves, and perioperative safety. Analyses included segmented regression, CUSUM, and correlation tests. Fifty knees (mean age 73 years, BMI 27) were included. Mean operative time was 97 min. Four complications occurred within 30 days, with no system failures. NASA-TLX scores declined significantly with case number (ρ = -0.54, p < 0.001), stabilizing after ∼8 cases. Operative time showed a breakpoint at 9 cases. Subscales improved earlier for mental demand, effort, temporal demand, and frustration, while performance stabilized later (∼19 cases). NASA-TLX correlated with operative time (r = 0.62, p < 0.001). Surgeon workload and operative efficiency improved in parallel, stabilizing after the first 8-10 RA-TKA cases. NASA-TLX is a practical tool for monitoring workload during robotic adoption and may guide training strategies in medium-volume institutions.