Archives of Orthopaedic and Trauma Surgery - 2026-04-17 - Journal Article
Long-term outcomes and revision-free survival following robotic-assisted unicompartmental and total knee arthroplasty.
Fleisher A, Kennedy M, Trudeau M, Piergrossi D, Madrid I, Meftah M
Topics
Key Takeaway
Robotic-assisted UKA and TKA demonstrated equivalent 5-year revision-free survivorship (97.6% vs. 96.2%, p=0.866) with similar 90-day ED visit and readmission rates in a single-center cohort with minimum 5-year follow-up.
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Summary
This single-center retrospective study compared perioperative outcomes and Kaplan-Meier revision-free survivorship between robotic-assisted UKA and TKA in 163 patients operated between 2011 and 2020. R-TKA had longer operative times (131 vs. 112.5 min, p<0.001), but 90-day ED visits (3.8 vs. 4.8%), readmissions (2.5 vs. 3.6%), and revision rates (3.8 vs. 4.8%) were statistically equivalent. Five-year revision-free survivorship was 97.6% for R-UKA and 96.2% for R-TKA with no significant log-rank difference (p=0.866).
Key Limitation
The significant difference in median follow-up between cohorts (9.55 vs. 6.07 years) means R-TKA patients had substantially less time at risk for revision, making direct survivorship comparison unreliable despite equivalent Kaplan-Meier curves at 5 years.
Original Abstract
BACKGROUND
While robotic assistance improves precision in unicompartmental (R-UKA) and total knee arthroplasty (R-TKA), long-term comparative data are limited. This study evaluated perioperative outcomes and mid- to long-term survivorship for R-UKA versus R-TKA.
METHODS
A retrospective review was performed of 163 patients who underwent primary, elective, R-UKA ( n = 84) or R-TKA ( n = 79) between 2011 and 2020 at a single, tertiary academic medical center, with a minimum follow-up of five years. Demographics, perioperative characteristics, and postoperative outcomes were compared between cohorts. Revision-free implant survivorship was evaluated using Kaplan–Meier analysis.
RESULTS
R-TKA procedures had longer operative times than R-UKA (131 vs. 112.5 min; P < 0.001) and both were performed primarily for primary osteoarthritis. Cohorts had similar 90-day ED visit rates (3.8 vs. 4.8%; P = 1), for both surgical (2.5 vs. 3.6%) and medical causes (1.3 vs. 1.2%), while readmission rates were also similar (2.5 vs. 3.6%, P = 1). Median follow-up (9.55 vs. 6.07 years) and time since surgery (12.33 vs. 7.48 years) were significantly longer for R-UKA (both P < 0.001). At final follow-up, revision occurred in 3.8% of R-TKA and 4.8% of R-UKA cases ( P = 1). Time to revision was shorter for R-TKA (1.36 vs. 5.22 years; P = 0.114). Kaplan–Meier analysis demonstrated 5-year revision-free survivorship of 96.2% for R-TKA and 97.6% for R-UKA, with the overall log-rank test showing no significant survivorship difference between groups ( P = 0.866).
CONCLUSIONS
In this cohort, R-UKA and R-TKA demonstrated favorable long-term survivorship with no statistically significant differences in ED visits, readmissions, or revision rates. These findings show comparable safety profiles and low revision rates at long-term follow-up for both procedures, suggesting that for patients meeting specific indications for either procedure, robotic-assisted knee arthroplasty provides durable outcomes for appropriately selected patients.