Clinical and mechanical outcomes of robotic-assisted versus conventional total knee arthroplasty: a retrospective propensity-matched analysis of 163,516 patients
Recommended Citation
Ghafarian A, Wajahath M, Hodson N, Saad J, Mehaidli A. Clinical and mechanical outcomes of robotic-assisted versus conventional total knee arthroplasty: a retrospective propensity-matched analysis of 163,516 patients. J Orthop Surg Res. 2026.
Document Type
Article
Publication Date
4-5-2026
Publication Title
J Orthop Surg Res
Keywords
90-day inpatient hospitalization encounter; Mechanical complications; Opioid utilization; Propensity-matched analysis; Real-world evidence; Revision surgery; Robotic-assisted total knee arthroplasty; Total knee arthroplasty; TriNetX database
Abstract
BACKGROUND: Total knee arthroplasty (TKA) achieves good overall outcomes, yet 15-30% of patients remain dissatisfied, often attributed in part to variability in implant positioning and soft-tissue balance. Robotic-assisted TKA (RA-TKA) aims to improve intraoperative accuracy, but its real-world association with postoperative healthcare utilization and mid-term mechanical outcomes remains uncertain at scale. This study compared 90-day utilization and complication outcomes and 2-year mechanical outcomes of RA-TKA versus conventional TKA (C-TKA) in a large, national propensity-matched cohort.
METHODS: This retrospective cohort study used the TriNetX US Collaborative Network to evaluate outcomes following primary TKA among adults undergoing TKA between January 2018 and January 2023. Patients receiving RA-TKA were identified and 1:1 propensity-matched to C-TKA patients based on demographics and comorbidities. Primary outcomes were 90-day inpatient hospitalization encounter and 90-day opioid prescription fill. Secondary outcomes included 2-year mechanical outcomes (revision TKA and mechanical loosening diagnoses). Analyses were performed within TriNetX using built-in propensity matching and risk ratio calculations with 95% confidence intervals. After propensity score matching, covariate balance was assessed using standardized mean differences, with values < 0.10 indicating acceptable balance.
RESULTS: PSM analysis yielded 6,176 pairs of RA-TKA and C-TKA patients (mean age 65.3 ± 8.6 years; 37.5% female; BMI 32.1 ± 8.7). RA-TKA was associated with lower 90-day inpatient hospitalization encounters (4.0% vs. 5.7%, RR 0.69; p < 0.001) and fewer opioid prescription fills (78.4% vs. 85.8%, RR 0.91; p < 0.001). Early medical and surgical complication rates were similar between groups (all p > 0.05). At 2 years, RA-TKA demonstrated lower rates of revision (1.3% vs. 2.2%, RR 0.58; p < 0.001) and mechanical loosening diagnoses (0.28% vs. 0.78%, RR 0.35; p < 0.001), with no difference in manipulation under anesthesia (3.26% vs. 3.22%, p = 0.919).
CONCLUSION: In this large propensity-matched national cohort, RA-TKA was associated with lower 90-day inpatient hospitalization encounters and opioid prescription fills, and lower coded revision and loosening outcomes at 2 years, while early complication rates were similar. These findings should be interpreted as associations given the use of administrative coding and unmeasured confounding.
PubMed ID
41937162
ePublication
ePub ahead of print
