MR-based outcome predictors of lumbar transforaminal epidural steroid injection for lumbar radiculopathy caused by herniated intervertebral disc.

OBJECTIVES

To evaluate the MR-based outcome predictors of lumbar transforaminal epidural steroid injection (ESI) for lumbar radiculopathy caused by herniated intervertebral disc (HIVD).

METHODS

A total of 149 patients (male/female 75:74; mean age 51.5 years) with the very worst (87 patients) or the very best outcome (62 patients) after ESI were enrolled in this study. They were selected from 1,881 patients who underwent lumbar transforaminal ESI for lumbar radiculopathy caused by HIVD from January 2007 to December 2008. Two radiologists reviewed MR in consensus. Chi-square test and Fisher's exact test were used to evaluate the difference between the two groups.

RESULTS

HIVD in the foraminal-extraforaminal zone were significantly more common in the very best outcome group (16/24, 66.6 %) than HIVD in the central-subarticular zone (46/125, 36.8 %) (P = 0.012). Other factors such as HIVD zone, T2-high signal, relation to nerve root, corner change, Modic change, disc height loss, grade of disc degeneration, and osteophyte were not statistically significant.

CONCLUSION

HIVD in the foraminal or extraforaminal zone is the only good MR-based outcome predictor of lumbar transforamial ESI for lumbar radiculopathy.