EPIDURAL CORTICOSTEROID INJECTIONS FOR SCIATICA DUE TO HERNIATED NUCLEUS PULPOSUS

Background Although epidural corticosteroid injections are commonly us ed for sciatica, their efficacy has not been established. Methods In a randomized, double-blind trial, we administered up to three epidural injections of methylprednisolone acetate (80 mg in 8 ml of isotonic sa line) or isotonic saline (1 ml) to 158 patients with sciatica due to a herniated nucleus pulposus. All patients had Oswestry disability scor es higher than 20 (on a scale of 1 to 100, with scores of 20 or less i ndicating minimal disability, and higher scores greater disability). R esults At three weeks, the Oswestry score had improved by a mean of -8 .0 in the methylprednisolone group and -5.5 in the placebo group (95 p ercent confidence interval for the difference, -7.1 to 2.2). Differenc es in improvements between the groups were not significant, except for improvements in the finger-to-floor distance (P=0.006) and sensory de ficits (P=0.03), which were greater in the methylprednisolone group. A fter six weeks, the only significant difference was the improvement in leg pain, which was greater in the methylprednisolone group (P=0.03). After three months, there were no significant differences between the groups. The Oswestry score had improved by a mean of -17.3 in the met hylprednisolone group and -15.4 in the placebo group (95 percent confi dence interval for the difference, -9.3 to 5.4). At 12 months, the cum ulative probability of back surgery was 25.8 percent in the methylpred nisolone group and 24.8 percent in the placebo group (P=0.90). Conclus ions Although epidural injections of methylprednisolone may afford sho rt-term improvement in leg pain and sensory deficits in patients with sciatica due to a herniated nucleus pulposus, this treatment offers no significant functional benefit, nor does it reduce the need for surge ry. (C) 1997, Massachusetts Medical Society.