Rise in serum C reactive protein after hip and knee arthroplasties in patients with rheumatoid arthritis

Objective-Serum C reactive protein (CRP) concentration was evaluated in pat ients with rheumatoid arthritis (RA) undergoing total hip arthroplasty (THA ) or total knee arthroplasty (TKA) to ascertain the postoperative CRP respo nse. Methods-Thirty seven consecutive patients with RA who had undergone THA or TKA were included in the study. The CRP concentration was measured in every patient once preoperatively and every other day for one week postoperative ly. Results-The peak median CRP concentration (94 mg/l) was achieved on the fir st and second day postoperatively and was seven times higher than the media n preoperative concentration (13 mg/l). CRP declined to the preoperative co ncentration in about one week. The rise of the CRP concentration was signif icant (p<0.001). No infection was encountered in this series. Conclusion-A rapid rise in the postoperative CRP concentration is normal in patients with RA treated by THA or TKA. The CRP concentration decreases to the preoperative value in about one week. Serial CRP measurements, includi ng at least one preoperative measurement, are needed when the clinical sign ificance of the postoperative CRP values is evaluated. When the postoperati ve CRF concentration remains raised for several days compared with the preo perative value, or even rises, it may indicate the presence of a complicati on in these patients.