Nationwide Comparison of Robotic and Navigation-Assisted Total Knee Arthroplasty: Trends, Perioperative Complications, and 90-Day Readmissions (2020–2022 NRD)

Background: Both robotic-assisted (RA-TKA) and navigation-guided (NG-TKA) total knee arthroplasty were developed to enhance component accuracy and alignment. While several studies have examined intraoperative precision and early outcomes, nationwide comparisons of postoperative complications and 90-day readmissions remain limited. Methods: retrospective cohort analysis was performed using the Nationwide Readmissions Database (NRD) 2020-2022, identifying elective primary TKAs performed with computer assistance. Robotic procedures were identified using ICD-10-PCS codes 8E0Y0CZ and 8E0YXCZ, and navigation procedures using 8E0YXBZ, 8E0YXBG, and 8E0YXBF. After exclusions, 1:1 propensity-score matching (caliper 0.01) was applied across demographics, comorbidities, hospital factors, and surgical year. Primary outcome was 90-day all-cause readmission; secondary outcomes included cause-specific readmissions, in-hospital complications, and healthcare resource utilization. Results: Among 72,827 elective computer-assisted TKAs, 48,491 (66.6%) were robotic and 24,336 (33.4%) navigation. Robotic utilization rose from 61.5% in 2020 to 71.0% in 2022 (p<0.001). After matching, 49,219 cases remained. In-hospital complications were generally low, but navigation-assisted TKA showed higher rates of sepsis (0.3% vs 0.1%), venous thromboembolism (0.3% vs 0.2%), pulmonary embolism (0.2% vs 0.1%), and blood transfusion (1.5% vs 0.5%) (all p<0.05). The 90-day readmission rate was similar (4.7% vs 4.6%, p=0.56), though readmission causes differed slightly (p<0.001), with navigation cases more often readmitted for infection, sepsis, or respiratory complications. Index charges were lower in robotic cases (USD 78,123 vs 88,344, p<0.001). Conclusions: Robotic-assisted TKA demonstrated lower perioperative complication rates and comparable short-term readmission risk compared with navigation-guided TKA, with modestly reduced hospital costs. These findings from the most contemporary national cohort support the expanding adoption of robotic systems in knee arthroplasty. Levels of Evidence: Level III