Diagnostic value of erythrocyte sedimentation rate combined with C-reactive protein in postprocedure discitis

Abstract

Background Previous investigations of the value of serum erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in postprocedure discitis were mainly focused on the relative power of ESR and CRP in the prediction of discitis outcome. Studies on the association between ESR combined with CRP and postprocedure discitis are limited. This study was done to investigate the diagnostic value of ESR combined with CRP measurements in postprocedure discitis. Methods From January, 2000 to October, 2008, 34 patients with postprocedure discitis who returned for back pain had repeat surgery. Forty patients who had spine surgery without recurrent back pain served as control group. Serum ESR and CRP levels were measured with the Westergren and immunonephelometry methodology. The difference attained between the two study groups was evaluated by logistic regression and receiver operating characteristic (ROC) curve analysis. Results The mean serum levels of ESR and CRP in postprocedure discitis (61.8±8.3 mm/h, 24.1±2.2 mg/L, respectively) were significantly higher than these levels in the control group (35.47±6.1 mm/h, 13.6±5.7 mg/L, respectively). Serum ESR combined with CRP measurements, which had a sensitivity of 79.4% and a specificity of 82.5%, had the best prognostic reliability. Significant differences were found when compared with the predictive value of a single ESR (sensitivity 70.16%, specificity 70%) or a single CRP (sensitivity 64.7%, specificity 70%). Conclusions ESR combined with CRP measurements between the first and second weeks after surgery is useful for diagnosing postprocedure discitis.