Infection risk assessment in patients undergoing primary total knee arthroplasty

To determine the incidence and to identify potential risk factors for in-hospital and late infections, as well as for deep periprosthetic joint infection (PJI) following TKA.

We identified 17,959 patients treated with primary TKA between 2000 and 2009. We recorded patient demographics, comorbidities and in-hospital complications. The rates of in-hospital, late, and deep PJIs were determined. Different logistic regression models were built to identify risk factors for each of the above types of infection.

The rates for in-hospital, post-discharge, and deep PJI were 0.65%, 0.41%, and 0.26%, respectively. Younger age, allogeneic blood transfusion, liver disease, and unilateral or staged bilateral TKA were risk factors for in-hospital infection. Renal and pulmonary disease, urinary tract infection, wound dehiscence, and prior in-hospital infection were risk factors for post-discharge infection. Male gender, history of in-hospital infection, prolonged length of stay, and pulmonary disease were identified as risk factors for deep PJI.

Despite low infection rates after primary TKA, there are patients at higher risk that would benefit by addressing modifiable risk factors for both in-hospital or post-discharge infections, including deep PJIs.