Change in Serum Markers Failed to Predict Persistent Infection after Two-stage Exchange ArthroplastyChange in Serum Markers Failed to Predict Persistent Infection after Two-stage Exchange Arthroplasty

Abstract

BackgroundTwo-stage exchange arthroplasty is a viable choice for prosthetic joint infection (PJI). After removing the infected prosthesis and implanting an antibiotic-loaded spacer in first stage, the proper timing of reimplantation is crucial for successful treatment. So far, there is no gold reference to determine the eradication of PJI before reimplantation. The combination of serum indicators, synovial white cell count (WBC), culture results, intraoperative histology, and clinical symptoms is used extensively to guide the timing of reimplantation. However, the proper timing of reimplantation was ill defined.PurposeWe wonder: (1) the utility of serum indicators, including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), interleukin-6 (IL-6) and fibrinogen, when predicted failure of reimplantation; (2) correlation between primary culture results and serum markers’ change.MethodA retrospective review of 226 patients treated with a two-stage exchange arthroplasty from 2014 to 2017 was conducted. PJI was diagnosed by using the Musculoskeletal Infection Society (MSIS) criteria. Serum biomarkers and organisms results at the set of PJI diagnosis and reimplantation were reviewed. Treatment success was defined according to the Delphi consensus criteria with a minimum follow-up of 2 year; receiver operator characteristic (ROC) depicted the utility of change in four serum markers when predicted failure.ResultsThe ROC area under the curves (AUC) was 0.543 in CRP, 0.572 in IL-6, 0.621 in ESR, 0.463 in fibrinogen and the combination of them was 0.709 when predicted persistent PJI using value change. The AUC of ROC was 0.521 in CRP, 0.472 in IL-6, 0.413 in ESR, 0.552 in fibrinogen and the combination was 0.630 when determine reimplantation by percent change. No significant association was found between culture results and change in serum markers.ConclusionNeither percent change nor value change in serum makers was proved to be poor markers when predicted persistent PJI, and initial causative organism didn’t influence the normalize of serum markers. Persistent PJI after TJA was still tough to diagnose. The combination of clinical symptom, pathology results, synovial fluid analysis and serum markers may improve the utility.