The Effect of Uncomplicated Knee Arthroscopy on C-reactive Protein and Erythrocyte Sedimentation Rate
BACKGROUND: Anticipated changes in erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) following uncomplicated knee arthroscopy have not previously been described. AIM: We aim to identify these values to aid the management of patients who re-present with a suspicion of infection. MATERIALS AND METHODS: Patients between 18 and 50 years undergoing day-case arthroscopic knee surgery under the care of the senior authors were recruited. Patients undergoing any bony intervention and those with a known inflammatory arthropathy were excluded from the study. Ethical approval was granted and patients consented to the study. ESR and CRP measurements were performed immediately prior to surgery, then at 1, 7, and 14 days postoperatively. RESULTS: A total of 29 patients consented to the study. A full set of results were achieved for 17 patients. There was a significant increase in CRP on day 1 and day 7 following knee arthroscopy with a mean increase of 4.55 mg/L (P = 0.003) on day 1 and 1.78 mg/L (P = 0.026) on day 7. ESR did not change significantly at any of the measured points. The maximum value for CRP was 16 mg/L on day 1 and 11.5 mg/L on day 7. All CRP measurements had returned to baseline (<5 mg/L) by 14 days. DISCUSSION AND CONCLUSION: Our study suggests that CRP measurement is a useful tool in the investigation of possible joint infection following simple knee arthroscopy. Continued elevation of CRP beyond 14 days or any significant elevation is not usual and suggests an abnormal post-operative recovery, which should prompt further investigation.