The Risk of Acute Infection Following Intra-articular Corticosteroid Injection Into a Pre-existing Total Knee Arthroplasty

Abstract

BackgroundNo previous studies have investigated the risk of infection following intra-articular corticosteroid injection (IACI) into a pre-existing total knee arthroplasty (TKA). The aim of this study is to determine the risk of acute infection following IACI into a pre-existing TKA. MethodsA retrospective chart review identified all patients at a single institution between October 2009 and May 2015 that had an ipsilateral knee injection subsequent to a TKA. The risk of acute infection, as defined by development of an infection within 3 months of IACI, was determined via review of clinic notes, operative reports, laboratory records, and telephone interviews. ResultsA total of 1845 injections in 736 patients met the inclusion criteria. In total, 101 (4.8%) patients were lost to follow-up. Three infections in 3 patients occurred within 3 months of IACI, yielding an infection rate of 0.16% per injection, or 1 infection in every 625 IACIs following TKA. ConclusionThis study is the first to investigate the risk of acute infection following injection of corticosteroid into a pre-existing TKA. Given the dire consequences of infection following TKA, the routine use of IACI into a pre-existing TKA should be avoided, and a thorough workup should be performed in any patient with a painful TKA prior to consideration of IACI.