Objective
This study is designed to compare the therapeutic effect of continuous epidural injection with catheter and intermittent epidural injection without catheter in the patients with low back pain.

Method
One hundred and nine patients with low back pain were randomly divided into two groups. First group (49 patients) were treated with two or three times of intermittent epidural injections with steroid mixed with local anesthetics. Second group (60 patients) were treated with continuous steroid mixed with local anesthetics injection through epidural catheter. The effect of the epidural injections was assessed by visual analog scale (VAS) at pre-injection and post- injection.

Results
Pre- and post-injection VAS scores of the first group were 6.5⁑1.2 and 3.5⁑1.5, respectively. Pre- and post-injection VAS scores of the second group were 6.2⁑1.6 and 2.3⁑1.1, respectively. VAS score changes between pre-and post-injection were significant (p＜0.01) in both groups. VAS score changes between two groups were greater (p＜0.01) in the second group. The more severe the disc herniation (protrusion and extrusion) in MRI finding, the more marked VAS score changes in the second group. When morbidity period was less than 1 year, the VAS score changes in the second group were greater (p＜0.05).

Conclusion
The therapeutic effect of catheter inserted continuous epidural injection is better than that of intermittent epidural injection in patients with low back pain.