PURPOSE: Robotic-arm-assisted surgery is increasingly used in orthopaedics due to its potential clinical benefits. This real-world data analysis evaluated the impact of image-based, robotic-arm-assisted total knee arthroplasty (raTKA) over non-robotic-arm-assisted total knee arthroplasty (nraTKA) on perioperative outcomes in Germany based on a large, multi-hospital administrative dataset. METHODS: This observational, cohort study used a large set of pooled administrative data from 91 hospitals from 2018 to 2023. Perioperative outcomes analysed included length of stay (LOS), extended hospitalization, inpatient complications, blood transfusions and intensive care unit (ICU) admission. A two-stage model was conducted: propensity score matching (PSM) to balance various patient characteristics, followed by multi-level regression analysis with hospital-level random intercepts to account for hospital effects. Using this multi-level model specification accounts for hospital-level differences in institutional practices. Significance was set at p < 0.05, and 95% confidence intervals were consistently reported. RESULTS: A total of 63,931 TKA cases were included: 11,305 raTKA and 52,626 nraTKA. PSM successfully eliminated baseline differences between groups, with all raTKA matched 1:1 to nraTKA controls. raTKA was associated with a 0.99-day shorter LOS (confidence interval CI -1.04 to -0.93), corresponding to a 14% reduction relative to the median LOS of nraTKA and a significant reduction in the risk of extended hospitalization (2266 vs. 5372 events, odds ratio OR = 0.375, CI 0.334-0.420). The risk of inpatient complications (93 vs. 186 events, OR = 0.728, CI 0.727-0.729), blood transfusions (68 vs. 118 events, OR = 0.435, CI 0.293-0.644) and ICU admission (220 vs. 459 events, OR = 0.495, 0.398-0.615) were also significantly lower in the raTKA group. CONCLUSIONS: In this real-world analysis of 63,931 cases from 91 German hospitals, raTKA is associated with clinically and statistically significant improvements in perioperative outcomes compared to non-robotic procedures. These clinical improvements might translate into cost efficiencies that can compensate for extra procedural costs of raTKA; however, the economic impact of raTKA should be examined further, considering also long-term outcomes and their health economic implications. Employing a large real-world data set, closely matched cohorts and explicit adjustment for hospital-level effects, this study isolates associations between raTKA and perioperative outcomes that are not solely attributable to institutional differences between hospitals and thus provides valuable information for policymakers and hospital decision-makers. LEVEL OF EVIDENCE: Level III, retrospective comparative, cohort study.
Tuecking et al. (2026) studied this question.