Risk Factors, Diagnoses, and Clinical Characteristics of Synchronous and Metachronous Periprosthetic Joint Infections Following Total Joint Arthroplasty.

BACKGROUND: Although multiple PJIs (periprosthetic joint infections), either synchronous or metachronous, occur in up to 20% of patients who have an index PJI after total joint arthroplasty (TJA), there remains a lack of understanding regarding multiple PJI risk factors, diagnosis, and management. Therefore, we asked: (1) What risk factors have been identified for synchronous and metachronous PJI after TJA compared to single-PJI patients? (2) What is the clinical relation of additional PJIs to the index PJI (time and location)? (3) Are the infectious organisms in multiple PJIs the same? and (4) Are clinical suspicion and blood cultures reliable in working up a possible multiple PJI?

METHODS: PubMed, Medline, Embase, Google Scholar, and EBSCOhost were queried to identify studies assessing prevalence, risk factors, and clinical features of synchronous and metachronous PJI following TJA through December 2024. A total of 372 distinct articles were retrieved. After screening, 18 studies were included, comprising 3,292 patients.

RESULTS: Primary risk factors for developing multiple PJIs included having 3+ prosthetic joints, methicillin-resistant Staphylococcus aureus (MRSA) in the joint space, and positive blood cultures. Metachronous PJI comprised roughly two-thirds of multiple PJIs, with 80% presenting within one year of the index PJI. Additionally, 72 to 90% of synchronous and metachronous PJI involved the contralateral knee prosthetic joint. Identical organism cultures were found in 72.7% of synchronous PJI cases and up to 88.9% of metachronous PJI cases. Blood cultures were inconsistent in differentiating single from multiple PJIs, but clinical suspicion of multiple PJIs was found to be highly specific.

CONCLUSIONS: Our findings suggest that sepsis and MRSA from local tissue are major risk factors for multiple PJIs, necessitating frequent monitoring of patients who have primary PJI. Surgeons should maintain a high suspicion for Staphylococcus and polymicrobial infections, standardize blood culture reporting, and closely monitor preimplanted prostheses, as multiple PJIs can remain elusive.

LEVEL OF EVIDENCE: Level III, Therapeutic study.