Complications and costs of patellofemoral arthroplasty versus total knee arthroplasty

Background: Patellofemoral arthroplasty (PFA) is an alternative to total knee arthroplasty (TKA) for the treatment of patellofemoral arthritis. Although PFA may preserve native kine-matics and accelerate recovery, it has been associated with higher revision rates. The pur-pose of this study is to compare complication rates and costs between PFA and TKA.Methods: Using the PearlDiver database, 6,179 patients with isolated patellofemoral arthri-tis treated with PFA or TKA from 2010-2015 were retrospectively reviewed with 5-year fol-low up. PFA and TKA patients were matched by age, sex, and Elixhauser Comorbidity Index via a 1:1 stepwise algorithm. Five-year costs and complications were compared between matched cohorts. The lifetime costs of PFA and TKA were evaluated with Markov decision modeling.Results: Compared to TKA, PFA was associated with fewer Emergency Department (ED) vis-its (6.1% vs 3.9%, p = 0.004) but a higher 5-year revision rate (9.9% vs 4.2%, p < 0.001). After multivariate regression, PFA was independently more likely to require revision (odds ratio 2.60, 95% confidence interval 1.32-4.71, p = 0.003). PFA was associated with lower total healthcare costs at every time point between 3 months ($18,014 vs $26,473, p < 0.001) and 5 years ($20,837 vs $27,942, p < 0.001). On average, the lifetime cost of PFA per patient was $5,235 less than for TKA ($26,343 vs $31,578).Conclusions: PFA is a less expensive alternative to TKA with a similar risk of medical com-plications but is associated with a significantly higher 5-year revision rate. Future studies should examine the reasons for PFA failure and methods to mitigate this risk.(c) 2022 Elsevier B.V. All rights reserved.