Factors associated with failure of surgical revision and IV antibiotics to resolve Cutibacterium periprosthetic infection of the shoulder.

PURPOSE: Cutibacterium is the most common organism causing shoulder periprosthetic infection (PJI). While most shoulder PJIs are well treated by prosthesis exchange and antibiotics, in some cases this treatment fails to resolve the infection. The factors associated with these failures have not been previously identified. The aim of this study was to identify the characteristics of patients with failure of treatment for PJI. METHODS: Thirty-five patients suspected of having Cutibacterium PJI had revision arthroplasty with single-stage implant exchange followed by intravenous antibiotics. The characteristics of those with ≥ two positive cultures at revision surgery were compared to those who did not. The characteristics of those patients having a re-revision with ≥ two positive deep cultures (documented treatment failures) were compared to those who did not. RESULTS: The 17 patients that had ≥ two positive cultures at their index revision were more likely to be male, to have had ream and run procedures, and to have higher loads of Cutibacterium on pre-operative cultures of their unprepared skin. The five patients that had documented treatment failure had higher loads of Cutibacterium on their skin and in deep cultures obtained at their index revision. CONCLUSION: Patients harboring high loads of Cutibacterium on their unprepared skin prior to revision and high loads of Cutibacterium on deep cultures at the time of their index revision are at increased risk for failure of implant exchange and antibiotics to resolve a Cutibacterium PJI.