Discriminating extrusive and bulging disk herniations by using serum hs CRP

It has been proposed that because there is inflammation around the nerve roots in disk herniation, there might be an association between serum C Reactive Protein (CRP) with this disease. This study aimed to distinguish between two forms of disk herniation (extrusion, bulging) by comparing the level of serum high-sensitivity CRP (hs CRP). In this perspective study, a total of 62 candidates for lumbar disk herniation surgery were recruited in Tabriz Imam Reza Hospital from 2012 to 2013. The patients categorized in two groups; with extrusion (n = 34) and with bulging (n = 28). Pre-operative serum hs CRP was measured by turbidimetric immunoassay. Both extrusion and bulging groups were matched for their patients' sex (males: 61.8% vs. 57.1%, respectively; p = 0.71) and age (mean: 52.22 +/- 7.32 years vs. 49.69 +/- 9.40 years, respectively; p = 0.48). The mean serum hs CRP was significantly higher in the extrusion group (3.56 +/- 2.90 with a range of 0.1 to 19 mg dL(-1) vs. 0.74 +/- 0.91 with a range of 0 to 5 mg dL(-1); p < 0.001). Based on the results of the receiver operator characteristics (ROC) cure, a cut-off point of hs CRP was =2.6 was highly indicative of extrusion, with a sensitivity and specificity of 66 and 63%, respectively. Based on the findings of the present study, the mean serum hs CRP is significantly higher in the patients with extrusive disk herniation vs. those with bulging. The proposed cut-off point may be useful as a preliminary indicator of the type of herniation, before more detailed imaging becomes available.