Does Resident Rotation Affect the Learning Curve of Active Robotic TKA? A Study of Surgical Efficiency and Radiographic Precision

TL;DR

This study shows that robotic TKA surgery becomes more efficient after 39 cases, even with rotating residents, without affecting precision.

Contribution

The study identifies a learning curve for active robotic TKA and confirms its precision despite resident rotation.

Findings

Operative time decreased by 20 minutes after the 39th case.

Implant positioning and alignment remained precise throughout the study.

Case number was the sole predictor of surgical duration.

Abstract

Background and Objectives: Learning curves robotic arm-assisted total knee arthroplasty (TKA) are well-documented for semi-active systems, but evidence for advanced fully active robotic systems remains scarce. This study aimed to characterize the learning curve for operative time, implant positioning, and lower-limb alignment using a fully active robotic TKA system, specifically accounting for the impact of rotating resident involvement in a tertiary center. Materials and Methods: Sixty consecutive primary TKAs were performed using the advanced active robotic system (CUVIS-Joint®). The learning curve for operative time was evaluated using cumulative summation (CUSUM) analysis. To identify independent predictors of surgical duration and radiographic precision, a multivariate linear regression model was constructed, including case number, implant type, and resident rotation period as variables. Results: CUSUM analysis identified a statistically significant inflection point at the 39th case. Beyond this point, mean operative time decreased approximately 20 min (133.3 ± 13.5 vs. 113.8 ± 7.9 min, p < 0.001). Multivariate regression confirmed that case number was the sole independent predictor of operative time (p < 0.001). Notably, implant positioning and lower-limb alignment showed no detectable difference across the sequential cases (p > 0.05), maintaining high precision from the outset. Conclusions: Active robotic TKA demonstrated a learning curve for operative time that stabilized after 39 cases within a clinical setting of rotational resident participation. Radiographic accuracy remained consistent despite these educational requirements, supporting the technical feasibility and reliability of this advanced system for the management of end-stage knee osteoarthritis

Figures