The Most Common Organisms in Periprosthetic Joint Infection: A Survey of the International Orthopaedic Device Infection Network.

BACKGROUND

Periprosthetic joint infection (PJI) remains a major source of morbidity, mortality, and economic burden, both in the United States and internationally. Understanding regional microbiology profiles in PJI is essential to assist with empiric antibiotic selection. The purpose of this study was to survey an international database to identify and compare the microbiological profile of hip and knee PJI across international sites.

METHODS

A multicenter, international database that included all patients admitted to participating hospitals who had a confirmed diagnosis of PJI was utilized. In the present study, data from four institutions in the following cities were retrospectively reviewed: Melbourne (Australia, n = 167), Groningen (the Netherlands, n = 117), Weston (Florida, United States of America, n = 201), and Charlotte (North Carolina, United States of America, n = 180). The most common organisms identified in hip and knee PJI were compared between institutions. Rates of polymicrobial, fungal, and culture-negative PJI specifically were also evaluated. A total of 665 patients who had PJI were included (311 hip and 354 knee).

RESULTS

Coagulase-negative staphylococci were the most frequently isolated pathogens across all centers (26.5 to 38%), followed by Staphylococcus aureus (13 to 27%). Rates of polymicrobial PJI were high and varied widely between institutions (14 to 51%), whereas rates of fungal PJI were low and consistent between regions (1 to 3%). The prevalence of culture-negative PJI varied between 8% (Australia) and 22% (Florida).

CONCLUSIONS

While subtle regional differences in the microbiology of PJI exist, Staphylococcus species remained the dominant pathogen, accounting for nearly half of the PJIs at each center. Differences in polymicrobial and culture-negative infections emphasize the impact of institutional and geographic factors, supporting the development of region-specific empiric and prophylactic antibiotic protocols.