How to handle concomitant asymptomatic prosthetic joints during an episode of hematogenous PJI, a multicentre analysis.

Introduction Prosthetic joints are at risk of becoming infected during an episode of bacteremia, especially during S. aureus bacteremia. However, it is unclear how often asymptomatic PJI occurs and whether additional diagnostics should be considered. Methods In this multicenter study, we retrospectively analyzed a cohort of patients with a late acute (hematogenous) PJI between 2005-2015 who had concomitant prosthetic joints in situ. Patients without at least 1 year of follow -up were excluded. Results 91 patients with a hematogenous PJI and 108 concomitant prosthetic joints were included. The incident PJI was most frequently caused by Staphylococcus aureus (43%), followed by streptococci (26%) and Gram negative rods (18%). Of 108 concomitant prosthetic joints, 13 were symptomatic, of which 10 were subsequently diagnosed as a second PJI. Of the 95 asymptomatic prosthetic joints, 1 PJI developed during the follow-up period and was classified as a 'missed' PJI at the time of bacteremia with S. aureus (1.1%). Infected prosthetic joints were younger than the non-infected ones in 67% of cases, and prosthetic knees were affected more often than prosthetic hips (78%). Conclusion During an episode of hematogenous PJI, concomitant asymptomatic prosthetic joints have a very low risk of being infected, and additional diagnostic work-up for these joints is not necessary.