Perioperative Changes in C-Reactive Protein Levels after Unilateral and Simultaneous Bilateral Total Knee Replacement

Abstract

Purpose: The objective of this study was to determine the patterns of C-reactive protein (CRP) changes during the postoperative period after total knee replacement (TKR), and to determine the CRP changes associated with infection after TKR. Materials and Methods: A retrospective analysis of the pattern of CRP changes during the first 6 postoperative months was conducted on 2,315 patients who underwent unilateral or simultaneous bilateral TKR. This data was also compared with the pattern of CRP changes which occurred in 19 patients with a deep prosthesis infection who were not enrolled in the main study. Results: The CRP levels peaked 3 days postoperatively, and then decreased to baseline levels at 15-28 days postoperatively. Within 14 days postoperatively, the CRP levels were significantly higher in the simultaneous bilateral TKA group than in the unilateral group (p<0.01). Thereafter, no significant difference in CRP levels existed between two groups. After the 8 th postoperative day, a significant difference in CRP level existed between patients with and without deep prosthesis infections. Conclusion: CRP changes post-TKR provide an effective means of monitoring of infections. In cases of non-inflammatory arthritis in which the CRP levels are significantly difference after the 8 th postoperative day or are elevated after the 4 th postoperative week, an infection should be suspected.