Manual vs robotic patellofemoral arthroplasty outcomes: A Michigan arthroplasty registry collaborative quality initiative-based study.

Background: Historically, all patellofemoral arthroplasty (PFA) was performed manually. Recently, robotic-assisted PFA has gained popularity. The purpose of this study was to determine whether a robotic-assisted technique influenced outcomes and revision rates. We hypothesized that robotic-assisted PFA would have improved 90-day complication and revision rates. Methods: A single center's data from the Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI) was queried for all primary PFAs from January 2014 to December 2022. Manual and robotic cohorts were compared for revisions and 90-day complications, including emergency visits, readmissions, and returns to the operating room (OR). Chi-square and Fisher's exact tests were used for categorical data and t-tests for continuous data. Results: Among 75 PFAs (mean age 53.0 ± 12.9 years, 78% women), 19 were manual and 56 robotic. Manual PFA experienced more 90-day complications (31% vs 10%, p = 0.0321) and a longer mean length of stay (30.9 ± 14.4 vs 20.6 ± 17.7 h, p = 0.03). No significant differences existed in age, BMI, gender, race, surgical time, 30-day complications, or revision rate. Manual PFA had no revisions, while 5% of robotic PFAs were revised for osteoarthritis progression, with a mean conversion time of 4.5 ± 2.7 years. Five-year cumulative percent revision (CPR) for all PFAs was 7.37%. Logistical regression showed manual PFA patients were more likely to experience 90-day complications (OR 3.84, p = 0.04). Conclusions: Manual PFA were prone to more 90-day complications and longer hospital stays compared to robotic PFA, which may minimize complications without affecting revision rates. Importantly, the PFA revision rate herein exceeded MARCQI-reported rates for unicompartmental and total knee arthroplasty.