A comparison of postoperative C-reactive protein changes in primary and revision hip arthroplasty in patients with rheumatoid arthritis.

C-reactive protein (CRP) response was studied in 40 consecutive patients with rheumatoid arthritis undergoing primary (n = 20) or revision (n = 20) total hip arthroplasty (THA). In patients with primary THA, the median preoperative CRP concentration was 10 mg/L (interquartile range [IQR], 6-17 mg/L), and the median change in CRP was 69 mg/L (IQR, 43-69 mg/L) at the 1st or 2nd postoperative day (P< .001). In the patients with revision THA, the results were 8 mg/L (IQR, 0-32 mg/L) and 48 mg/L (IQR, 21-78 mg/L) (P< .001). Median change in CRP from preoperative to postoperative values did not differ significantly among the patients with primary and revision THA. No correlation was found between the preoperative and perioperative background variables and the change in CRP compared with patients with primary and revision THA. It seems that the revision operation has no significant additional influence on the postoperative CRP response. More detailed analyses are needed to evaluate the significance of endocrine, metabolic, and inflammatory responses in these patients.