Significance of Perioperative Tests to Diagnose the Infection in Revision Total Shoulder Arthroplasty

Background: The purpose of this study was to evaluate the value of perioperative tests for the diagnosis of infectionin revision shoulder arthroplasty.Methods: A retrospective analysis was performed on 537 shoulder arthroplasties (429 patients) that underwent revisionshoulder arthroplasty at our institution. Periprosthetic tissue cultures were positive in 169/537 surgeries.Results: White-blood cell count (WBC) was elevated in 3.8% revision arthroplasties. Erythrocyte sedimentation rate (ESR)was elevated in 23.1% revision arthroplasties. The C-reactive protein (CRP) was elevated in 20.8% revision arthroplasties.Bone scans (technetium, indium) were performed on 9.9% patients and it was positive for osteomyelitis in just one revisionarthroplasty. Intra-operative pathology was read as consistent with acute inflammation in 11.9% revision arthroplasties.The positive and negative predictive values for intra-operative pathology were 56.7% and 71.6% respectively.Conclusion: All of the perioperative tests had a high specificity and negative predictive value, but low sensitivity andpositive predictive value.Level of evidence: III