What is a "periprosthetic shoulder infection"? A systematic review of two decades of publications.

PURPOSE: While as many as 50% of revision shoulder arthroplasties are culture positive, a consistent, clinically useful definition of a "periprosthetic shoulder infection" is lacking. We conducted a systematic review of the published literature with respect to (1) the definition of a "periprosthetic shoulder infection", (2) the pre-operative evaluation for possible infection, and (3) the harvesting and culturing of specimens at the time of surgical revision.

METHODS: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we identified 20 studies concerning infection at the time of revision shoulder arthroplasty. The review was registered in the international Prospective Register of Systematic Reviews.

RESULTS: An explicit definition of infection was not present in six studies (27%). Classification systems used for periprosthetic hip and knee infections were used in three studies (14%). Clinical signs and symptoms were used in all definitions, but most studies did not report microbiologic results or culturing practices.

CONCLUSIONS: Synthesis of the literature on failed arthroplasties with positive cultures is compromised by lack of standardization, leaving surgeons without secure evidence on which to base diagnostic and treatment decisions. These decisions would be better informed if authors used a consistent approach in the evaluation of failed arthroplasties with respect to the number and source of specimens submitted, the culture technique, the number of specimens that became culture positive, the bacteria identified, and the bacterial load recovered from the shoulder.

LEVEL OF EVIDENCE: This was a systematic review of reports of all levels.