The Impact of Culture Negativity on the Outcomes of Revision Total Knee Arthroplasty for Chronic PJI

Abstract

Culture-positive (CP) and culture-negative (CN) periprosthetic joint infections (PJI) remain a crucial area of research; however, current studies comparing these infections rely on unstandardized outcome reporting tools. Our study aimed to compare the outcomes of CP and CN PJI using the standardized Musculoskeletal Infection Society (MSIS) outcome reporting tool. We retrospectively reviewed 138 patients who were diagnosed with PJI and indicated for two-stage revision total knee arthroplasty (rTKA). The majority of patients in both CP and CN cohorts achieved infection control without the need for reoperation (54.1% and 62.5%, respectively). There was a significant difference in the overall distribution of MSIS outcomes (p=0.043), with a significantly greater rate of CN patients falling into Tier 1 (infection control without the use of suppressive antibiotics) (52.5% versus 29.6%, p=0.011). There was also a significant difference in the distribution of septic versus aseptic reoperations after 2nd stage (p=0.013), with more CP reoperations being septic and more CN reoperations being aseptic. The duration from 1st to 2nd stage was significantly shorter in the CN cohort (p=0.002). While overall infection control was similar between cohorts, these data suggest that the outcomes of two-stage rTKA are favorable in cases of CN PJI.