Combined serum and synovial C-reactive protein tests: a valuable adjunct to the diagnosis of chronic prosthetic joint infection

Abstract

Background Diagnosis of periprosthetic joint infection (PJI), especially chronic PJI, is very confusing and challenging. The value of C-reactive protein (CRP) in infectious diseases has been recognized, but the diagnostic value of CRP in chronic PJI is unknown. Our aim was to investigate the diagnostic value of synovial CRP in chronic PJI and to explore the role of combined serum and synovial CRP in distinguishing chronic PJI from aseptic failure after knee and hip arthroplasties. Methods We prospectively enrolled patients scheduled to have a revision surgery for chronic PJI or aseptic loosening from January 2019 to December 2020, in which synovial CRP was additionally measured along with routine preoperative diagnostic serum ((ESR, CRP) and synovial (PMN%) biomarkers. The receiver operating characteristic (ROC) curves and area under the curve (AUC) were analyzed for each biomarker to determine diagnostic efficacy. Results There were no statistically significant differences between the infection (n = 39) and aseptic (n = 58) groups, including 61 hips and 36 knees. The synovial CRP levels were significantly higher in the infection group than in the aseptic group (median: 9.93 mg/l vs 3.58 mg/l; p < .001). The optimal cut-off value for detecting chronic PJI of Synovial fluid (SF) CRP was of 7.26 mg/l with a sensitivity of 84.62%, a specificity of 93.10%. The combined model I (Serum CRP > 10.2 mg/l OR SF CRP > 7.26 mg/l) had a negative predictive value (NPV) of 96.67%, and a sensitivity of 97.44%. The combined model II (Serum CRP > 10.2 mg/l AND Synovial CRP > 7.26 mg/l) led to a specificity of 1, and a positive predictive value (PPV) of 1. Conclusions The present study demonstrated that the combination of serum and synovial CRP can be used as an adjunct to the diagnosis of chronic PJI.

Predicting the Exception—CRP and Primary Hip Arthroplasty

“…The development of a PJI prolongs the inpatient stay considerably [31,32]. The maximum CRP and the presence of a second peak can be helpful for early infection detection [33][34][35]. This study was able to demonstrate the clinical applicability of two formulas forecasting a PJI.…”

Reliable Diagnostic Tests and Thresholds for Preoperative Diagnosis of Non‐Inflammatory Arthritis Periprosthetic Joint Infection: A Meta‐analysis and Systematic Review

“…1, and the QUADAS‐2 score criteria revealed that most of the extracted studies had high risks. Excluding brand new markers that only appeared recently and have limited data, 129 records reported diagnostic information of serum markers (serum CRP, ESR, procalcitonin, IL‐6, D‐Dimer, WBC, platelet count [PLT], neutrophil to lymphocyte ratio [NLR], monocyte to lymphocyte ratio [MLR], platelet to lymphocyte ratio [PLR], platelet to mean platelet volume ratio [PVR], FDP [fibrin degradation product] and Fibrinogen), 9–11,24–149 114 studies reported synovial markers (synovial WBC, PMN%, IL‐6, IL‐1β, CRP, TNF‐α, Calprotectin, and leucocyte esterase [LE] and laboratory or lateral‐flow based α‐defensin test),…”

“…Final analysis was performed on 215 articles with six additional studies searched manually, as shown in platelet to mean platelet volume ratio [PVR], FDP [fibrin degradation product] and Fibrinogen), [9][10][11] 114 studies reported synovial markers (synovial WBC, PMN%, IL-6, IL-1β, CRP, TNF-α, Calprotectin, and leucocyte esterase [LE] and laboratory or lateral-flow based α-defensin test), 10,29,31,34,36,43,49,51,52,58,59,61,62,64,65,[72][73][74]76,77,[79][80][81][84][85][86][87][88]90,95,97,99,117,118,122,124,125,127,129,132,[135][136][137][138]142,1...…”

Serum acute‐phase protein concentrations following uncomplicated total hip arthroplasty in dogs

“…The magnitude and the timing of peak concentrations, as well as the duration of elevation, vary between each test and type of procedure 20,21 . C‐reactive protein levels peak on postoperative day 2 and return to preoperative levels by day 21 in uncomplicated total hip arthroplasty (THA) in humans; elevations that persist beyond established acute and chronic time points are highly indicative of infection 14–24 …”

“…20,21 C-reactive protein levels peak on postoperative day 2 and return to preoperative levels by day 21 in uncomplicated total hip arthroplasty (THA) in humans; elevations that persist beyond established acute and chronic time points are highly indicative of infection. [14][15][16][17][18][19][20][21][22][23][24] Serum CRP and serum amyloid A (SAA) are reliable biomarkers of inflammation in dogs, [25][26][27][28] with some evidence that SAA is better able to differentiate between inflammatory and noninflammatory states than CRP. 29 Acute-phase proteins in dogs with postoperative orthopedic infection have been investigated previously, 30 but their clinical utility for dogs undergoing joint replacement surgery is unknown.…”