Preoperatively elevated serum inflammatory markers increase the risk of periprosthetic joint infection following total knee arthroplasty in patients with osteoarthritis.

BACKGROUND

The purpose of this study was to evaluate the prevalence of preoperatively elevated serum inflammatory markers and to determine its association with periprosthetic joint infection (PJI) in patients with osteoarthritis (OA) undergoing total knee arthroplasty (TKA).

METHODS

From January 2010 to May 2014, we retrospectively reviewed 3,376 consecutive patients who were scheduled for unilateral TKA due to OA. Patients with inflammatory arthritis, posttraumatic arthritis, previous knee surgery, simultaneous surgery or arthroplasty, and comorbidity with autoimmune disease, hepatitis, renal disease, respiratory tract infections, urinary tract infection, and malignancy were excluded. One hundred and forty patients with preoperatively elevated erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) were enrolled. The control group was matched by age, sex, body mass index, and year of index surgery in 1:1 ratio. All patients were followed for a minimum of 1 year or until the occurrence of PJI. PJI was defined based on the criteria in the International Consensus Meeting. A multivariate Cox proportional hazards model was utilized to calculate the HR and 95% CI.

RESULTS

The prevalence of preoperatively elevated inflammatory markers was 4.1%. The rate of PJI was significantly higher in the both elevated ESR and CRP groups (12.5%, 4/32) compared with both normal group (1.4%, 2/140) and either high group (0.9%, 1/108) (P<0.001). Patients with preoperative elevated ESR and CRP had a significant risk of PJI compared to those with normal serum inflammatory markers (HR: 15.8, 95% CI: 2.57-96.7, P=0.003) after adjusting confounding factors. The cumulative rate for PJI was 6.3% (95% CI: 0%-14.27%) at 1 year and 16.5% (95% CI: 0%-30.66%) at 5 years for both high ESR and CRP groups, which was significantly higher than other 2 groups (P=0.0002).

CONCLUSION

Although the prevalence of preoperatively elevated ESR and CRP is low, routine examination of ESR and CRP preoperatively might be necessary to prevent subsequent PJI in patients with OA following TKA.