Comparison of Procalcitonin and C-Reactive Protein for the Diagnosis of Periprosthetic Joint Infection before Revision Total Hip Arthroplasty

Objective: To compare the clinical informative value of procalcitonin (PCT) and C-reactive protein (CRP) serum concentrations in the diagnosis of periprosthetic joint infection (PJI) before revision total hip arthroplasty (THA). Design and Methods: We conducted a prospective observational study of 71 consecutive patients (74 hips) undergoing revision THA. Procalcitonin and CRP serum concentrations and white blood cell (WBC) count were measured pre-operatively. Diagnostic accuracy was analyzed by the receiver-operating characteristic (ROC) curve and the area under the curve (AUC). Results: The PJI incidence was 35.2% in patients with revision THA. Procalcitonin and CRP serum concentrations and WBC count were statistically higher in the PJI cohort compared with the no PJI cohort (p<0.05). The AUCs for PCT, CRP, and WBC count were 0.851 (95% confidence interval [CI] 0.773-0.929), 0.830 (95% CI 0.751-0.910), and 0.633 (95% CI 0.518-0.747), respectively. Serum PCT and CRP showed a significantly higher diagnostic ability than WBC count (p<0.05). No significant difference was found between serum PCT and CRP (p=0.367). Conclusion: Procalcitonin does not offer an advantage over CRP in diagnosing PJI. However, PCT and CRP proved to be more reliable than WBC count.