Incidence, cost, and risk factors for early sepsis following revision total knee arthroplasty for periprosthetic joint infection.

INTRODUCTION: We aimed to estimate the incidence, predictors, and cost of sepsis within 90 days of revision of total knee arthroplasty (TKA) for periprosthetic joint infection (PJI).

METHODS: A retrospective analysis of first-time both-component revision TKA for PJI (n = 16,535) using a national all-payer database between 2016 and 2022 was performed. Patients were divided into those who developed sepsis within 90 days of revision TKA for PJI (n = 2365) and those who did not (n = 14,170). Overall and annual incidence of sepsis were estimated. Multivariate regression was performed to predict risk of 90-day sepsis following surgery. Average 90-day reimbursement per patient was compared between patients with and without sepsis after propensity score matching.

RESULTS: Overall, 14% of patients developed sepsis within 90 days of surgery. Male gender (OR 1.2, p < 0.001), renal failure (OR 1.2, p < 0.001), tobacco use (OR 1.1, p < 0.01), morbid obesity (OR 1.1, p = 0.01), Elixhauser Comorbidity Index (ECI) (OR 1.08, p < 0.001), and hypoalbuminemia (OR 1.1, p = 0.03) were associated with a higher risk of sepsis within 90 days of revision TKA for PJI. Average reimbursement per patient in the 90 days following surgery was significantly higher among patients who developed sepsis compared to those who did not ($15,979 vs $11,306, p < 0.001).

CONCLUSION: Approximately, 14% of revision TKA for PJI patients developed sepsis within 90 days. Male gender, renal failure, tobacco use, morbid obesity, higher ECI, and hypoalbuminemia independently increased the risk of sepsis. Optimizing modifiable risk factors such as smoking may help reduce the incidence and associated cost of sepsis following revision TKA for PJI.

LEVEL OF EVIDENCE: IV (retrospective).