Prevention of late PJI.

The definition of late PJI is variable in literature. Majority of the members of the consensus felt that any infection occurring after one year should be considered as late. Coventry defined stages of PJI, where Stage I is an acute infection that occurred within 3 months of the index procedure, Stage II is a delayed infection that occurred between 3 months and 2 years after the index procedure where there was no pain-free interval, and Stage III is a hematogenous infection where there is a pain-free stage [1]. Garvin and Hanssen defined a late chronic PJI as one that occurred 4 weeks after the index procedure with an insidious clinical onset [2]. McPherson et al defined a chronic infection as one that had symptoms for 4 weeks or longer [3]. In Sweden, a late PJI is defined as one that occurs 2 years after the index procedure. Due to the huge variation in time frames, we did not find consensus in defining a timeframe for a late PJI. However, we classified late PJI as late hematogenous PJI, where there was an asymptomatic period followed by clinical and/or radiographical signs of infection. The workgroup feels that late PJI arises as a result of bacteremia at a later stage [4] and should be distinguished with infections arising as a result of intraoperative contamination. Risk factors for late PJI are similar to those described for PJI in Workgroup 1 (Please see Question 1, Workgroup 1).