H. Mohamadipanah1, C. T. Millar1, D. N. Rutherford1, K. E. Law1, R. D. Ray1, C. M. Pugh1 1University Of Wisconsin,Department Of Surgery,Madison, WI, USA
Introduction:
Objective measures of surgical skill are needed to improve the feedback trainees receive during their surgical education. Research using motion tracking technology has helped to quantify surgeons' dexterity into performance metrics such as path length, working volume and motion smoothness. This work has successfully shown a difference in these metrics when comparing experts and novices. However, comparing motion metrics with end product quality could provide specific feedback on psychomotor skills and how trainees may improve task completion quality. The purpose of this study is to identify and model the relationship between motion metrics and a quantitative measure of end product quality (‘hernia repair score’) in a simulated laparoscopic ventral hernia (LVH) repair. We hypothesize that lower values of path length, working volume, and motion smoothness relate to higher hernia repair score.
Methods:
Surgical residents (PGY 2-3, N = 39) from Midwestern programs performed a simulated LVH repair. During the procedure, three electromagnetic sensors were placed on each hand (thumb, index finger, and wrist). Position data was used to calculate path length, working volume, and motion smoothness during the placement of the first transfacial suture. After the simulation, the hernia repair was rated using a previously validated checklist to score the quality of mesh attachment on a 24-point scale. To prepare the data, a log transform was applied to the motion smoothness data and factor analysis was used to combine metrics from the six sensors into one or two standardized variables. The relationship between these standardized variables and hernia product score was modeled using linear regression.
Results:
Multiple regression analysis tested if path length significantly predicted hernia repair score. The results indicated that the path length of the dominant (β = -2.084, p = .021) and non-dominant hand (β = -1.830, p = .040) explained 26.1% of the variance in hernia repair score (R2 = .261, F(2, 30) = 5.284, p = .011). However, multiple regression analysis showed that working volume did not significantly predict hernia product score (R2 = .083, F(2, 31) = 1.412, p = .259). A simple regression analysis demonstrated that the log transform of motion smoothness (β = -2.878, p = .001) significantly predicted hernia product score, explaining 28.9% of the variance (R2 = .289, F(2, 31) = 12.616, p = .001).
Conclusion:
Regression analyses show that shorter path lengths and smoother movements significantly predict higher hernia repair quality. While the independent variables account for less than 30% of the variance, it is noteworthy that the motion metrics of a single stitch have significant, predictive validity for final product outcomes. While additional work is needed, these findings have significant implications for the potential use of motion tracking in measuring surgical performance.