Alpha-defensin-novel synovial fluid biomarker for the diagnosis of periprosthetic joint infection

Periprosthetic joint infection (PJI) continues to be a significant complication after total joint arthroplasty. Diagnosis of PJI can be challenging and elusive in the absence of a gold standard. This purpose of this article is to review the current evidence on the utility of serum and synovial fluid biomarkers to help aid in the diagnosis of PJI with focusing on synovial fluid alpha-defensin. Articles and data for this review were identified by searches of PubMed and Ovid MEDLINE up to June 1, 2016. In addition, we manually reviewed the bibliographies of the retrieved articles for additional citations for references from relevant articles on the diagnosis of PJI. Serum biomarkers can be elevated in various inflammatory conditions. Synovial fluid biomarkers are more accurate for the diagnosis of PJI compared to serum biomarkers. Based on current available data, alpha-defensin is the most promising synovial fluid biomarker for the diagnosis of PJI and is commercially available. Synovial fluid alpha-defensin could enhance our ability to identify PJI and incorporate into the diagnostic algorithm in the future. Large-scale studies are needed to provide more data for its significance for the diagnosis of PJI.