Diagnostic and Predictive Efficacy of Synovial Fluid Versus Serum C-Reactive Protein Levels for Periprosthetic Joint Infection and Reimplantation Success

Feilong Li; Haotian Zhou; Yaji Yang; Jianye Yang; Hai Wang; Ning Hu

doi:10.1016/j.arth.2024.04.054

Diagnostic and Predictive Efficacy of Synovial Fluid Versus Serum C-Reactive Protein Levels for Periprosthetic Joint Infection and Reimplantation Success

J Arthroplasty. 2024 Apr 24:S0883-5403(24)00377-2. doi: 10.1016/j.arth.2024.04.054. Online ahead of print.

Authors

Feilong Li¹, Haotian Zhou², Yaji Yang², Jianye Yang², Hai Wang³, Ning Hu²

Affiliations

¹ Department of Orthopaedics, The First Afﬁliated Hospital of Chongqing Medical University, Chongqing, China; Department of Orthopaedics, The People's Hospital of Dazu, Chongqing, China.
² Department of Orthopaedics, The First Afﬁliated Hospital of Chongqing Medical University, Chongqing, China.
³ Department of Orthopaedics, Fuling Central Hospital affiliated of Chongqing University.

PMID: 38670172
DOI: 10.1016/j.arth.2024.04.054

Abstract

Introduction: A two-stage exchange revision for periprosthetic joint infection (PJI) is associated with major risks for reinfection. Although serum markers are frequently used for diagnosis, their effectiveness remains debatable. Synovial fluid markers may offer a more accurate diagnosis of PJI; however, the importance of these biomarkers, notably synovial fluid C-reactive protein (syCRP), remains controversial, particularly in the context of reimplantation. The present study aimed to clarify these diagnostic uncertainties by evaluating the diagnostic efficacy of syCRP versus serum CRP (seCRP) levels in the context of PJI and recurring or persisting infections before reimplantation.

Methods: A total of 186 patients were enrolled and divided into two groups: aseptic revision (n = 112) and PJI revision (n = 74). Of the PJI group, 65 were categorized as success and 9 as failure, based on the presence of recurrent or persistent infection before reimplantation. The syCRP and seCRP levels and their changes were assessed preoperatively and in the first- and second-stage revisions. Additionally, receiver operating characteristic (ROC) curves and area under the ROC curves (AUC) were analyzed.

Results: Both seCRP and syCRP levels were significantly elevated in the PJI group compared with the aseptic group (P < 0.001). The ROC curve analysis highlighted the enhanced diagnostic accuracy of syCRP for PJI, with an AUC of 0.93 versus 0.80 for seCRP. Furthermore, syCRP proved to be more reliable in predicting reimplantation success, exhibiting an AUC of 0.86 versus 0.63 for seCRP. In evaluating trends in CRP levels to determine reimplantation timing, changes in syCRP levels demonstrated superior diagnostic utility, exhibiting an AUC of 0.79 versus 0.63 for changes in seCRP levels.

Conclusion: In assessing PJI and infections before reimplantation, syCRP may offer enhanced accuracy compared with seCRP. Nevertheless, variations in both syCRP and seCRP levels did not consistently predict the outcome of reimplantation.

Keywords: C-reactive protein; Diagnosis; Joint fluid; Periprosthetic infection.