Do Elevated Inflammatory Markers Associate With Infection in Revision Shoulder Arthroplasty?

Abstract

Background Serologic erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) measurements, which have been successfully utilized in the lower extremity, are thought to lack adequate sensitivity in the diagnosis of infection after shoulder arthroplasty. The purpose of this study is to determine the diagnostic performance of preoperative white blood cell (WBC) count, ESR, and CRP in the diagnosis of infection in the setting of revision shoulder arthroplasty with the gold standard of infection being defined as a later diagnosis of infection. Patients and methods A national insurance database between the years of 2007 and 2015 (PearlDiver, Warsaw, IN) was queried for those patients who underwent revision shoulder arthroplasty using a combination of procedural (common procedural terminology codes 23472 and 23474) and diagnostic codes (International Classification of Diseases [ICD]-9 code 81.97 and equivalent ICD-10 codes). This database contains demographics, laboratory data, and complication data to allow identification of patients with an infection within 1 year postoperatively. Results The database contained 1392 patients who met criteria. Among these, the best diagnostic performance was with a combined test which was positive if CRP, ESR, or WBC was positive with a sensitivity of 7% to 42%, a specificity of 92%, a positive predictive value of 8% to 45%, a negative predictive value of 91%, and an accuracy of 84% to 85%. On multivariate analyses, predictors included an abnormal ESR (odds ratio 2.4, P = .05) and male gender (3.8, <.001). Conclusions Those patients with an abnormal preoperative ESR have significantly increased odds of a subsequent infection following revision shoulder arthroplasty. ESR, CRP, and WBC in combination are specific but insensitive. Level of Evidence: Diagnostic, Level III