C‐reactive protein may rise after closed‐suction drainage removal in patients undergoing revision arthroplasty: a retrospective study

Background Serum C‐reactive protein (CRP) has been one of the most commonly used markers to rule out early post‐operative infection following total joint arthroplasty. The phenomenon that CRP values rise after prolonged drainage removal may occur in clinical settings. The purpose of this study is to investigate (i) the prevalence and risk factors of such a phenomenon and (ii) whether the raised CRP is associated with post‐operative infection. Methods A retrospective review of 72 revision arthroplasties of the knee and hip with prolonged drainage from 2011 to 2016 was conducted. Perioperative CRP levels were obtained, and patients were divided into two groups according to whether CRP levels were elevated after drainage removal (raised CRP group and control group). Multivariate logistic regression analyses were performed to identify risk factors of raised CRP after drainage removal. The incidence of post‐operative wound complications and infection was compared between groups. Results Overall, the prevalence of raised CRP after drainage removal was 29.17% (21/72). CRP level before drainage removal was associated with the occurrence of such a phenomenon (adjusted odds ratio per 10‐mg/L increase 0.92, 95% confidence interval 0.87–0.97). The raised CRP levels decrease again within 3 days after drainage removal. There was no significant difference in the incidence of wound complications and infection between the raised CRP group and control group. Conclusion Almost one in three patients have raised CRP values after prolonged drainage removal following revision arthroplasty. However, CRP values can decrease again within 3 days after drainage removal without specific management. Almost one in three patients have raised C‐reactive protein values after prolonged drainage removal following revision arthroplasty. However, C‐reactive protein values can decrease again within 3 days after drainage removal without specific management. Surgeons should remember that such a phenomenon may be not be a proxy for post‐operative infection following revision arthroplasty.