The MusculoSkeletal Infection Society Diagnostic Criteria are Insufficient to Diagnose Shoulder Periprosthetic Infection: a retrospective study case and literature review.

Periprosthetic shoulder infection (PSI) management is very complicated because of its unique microbiology and due to the heterogeneity of studies published about it. Nowadays, there isn't a strict consensus on the diagnosis. Nevertheless, the criteria established by the musculoskeletal infection society (MSIS) are generally used by the scientific community. The objective of this retrospective study case and literature review is to establish that the MSIS criteria are insufficient to diagnose PSI. We did a retrospective monocentric analysis concerning PSI. Out of the 25 shoulder arthroplasty revisions conducted in our institution from January 2010 till January 2022 (including primary implants placed in other facilities), 10 had a positive periprosthetic culture from samples taken during surgery. In 60% of cases, the diagnosis of PSI has been made because of 2 positive periprosthetic cultures (major criterion). In 10% of cases, the diagnosis of prosthetic shoulder infection was recognized from the presence of a cutaneous fistula in communication with the joint implants (major criterion). In no case was the diagnosis of PSI determined by the presence of 4 out of 6 minor MSIS criteria. In 30% of cases, the MSIS criteria were insufficient to establish the PSI diagnosis. The MSIS criteria are insufficient to establish the diagnosis of PSI and should be considered as a methodological bias in published studies on this subject.