Does Transitioning to Robotic-Assisted Total Knee Arthroplasty Change Surgeon Revision Risk or Failure Modes?: A Baseline Comparative Analysis Before and After Robotic Adoption.

Background: Robotic-assisted total knee arthroplasty (RA-TKA) may disproportionately affect revision rates based on a surgeon's revision profile. This national registry study (1) stratified surgeons by pre-RA-TKA revision rates as low, medium, or high and (2) compared the change in revision rates and modes of failure within each cohort after commencing RA-TKA. Methods: All TKA procedures performed for osteoarthritis and recorded by the Australian Orthopaedic Association National Joint Replacement Registry from September 1999 to December 2023 were screened for eligibility. A total of 178 surgeons were included, performing 85,075 TKAs since commencing RA-TKA. TKA with hinged, constrained or medial pivot bearings, and American Society of Anesthesiologists (ASA) Scores 4 and 5 were excluded. Surgeons were stratified into quartiles based on their 2-year cumulative-percent-revision (CPR) rates before commencing RA-TKA into low (2-year CPR ≤1%), middle (1%-2.5%), and high revision cohorts (≥2.5%). The primary outcome was CPR with comparisons between time-matched RA-TKA and non-RA-TKA for each surgeon cohort after commencing RA-TKA. Secondary outcomes were changes in failure modes. Cox proportional hazards modelling controlled for age, sex, body mass index, ASA, patellar resurfacing, surgical year, fixation, polyethylene, and bearing type. Results: After commencing RA-TKA, there was no difference in CPR between RA-TKA and non-RA-TKA in low (hazard ratio [HR] 1.27; 95% CI 0.84-1.91; Conclusions: At a grouped cohort level, commencing RA-TKA does not improve revision rates nor change failure modes. Surgeons with higher revision rates before commencing RA-TKA experienced further increases in revision rates. Level of Evidence: Level III. See Instructions for Authors for a complete description of levels of evidence.