Corticosteroids in peri-radicular infiltration for radicular pain: a randomised double blind controlled trial. One year results and subgroup analysis

The objective of this study is to evaluate the efficacy of corticosteroids in patients with radicular pain due to lumbar disc herniation or lumbar spinal stenosis through a prospective randomised, double blind controlled trial, and whether there was an effect on subsequent interventions such as additional root blocks or surgery. Peri-radicular infiltration of corticosteroids has previously been shown to offer no additional benefit in patients with sciatica compared to local anaesthetic alone. It is not known if the response to peri-radicular infiltration is less marked in certain subgroups of patients such as those with radicular pain due to lumbar spinal stenosis. Previous studies have suggested that peri-radicular infiltration of corticosteroids may obviate the need for subsequent interventions and we therefore further investigated this in the current study. We randomised 150 patients to receive a single injection with either bupivacaine alone or bupivacaine and methylprednisolone. Patients were assessed at 6 weeks and 3 months after the injection using standard outcome measures including Oswestry Disability Index (ODI), visual analogue score for leg pain and patient’s subjective assessment of outcome. At 1-year follow-up, we looked at the outcome in terms of the need for subsequent interventions such as additional root blocks or surgery. At 3-month follow-up, there was no statistically significant difference in the standard outcome measures between the two injection groups. At a minimum 1-year post injection, there was no difference in the need for subsequent interventions in either group. Patients with lumbar spinal stenosis had a less marked reduction in the ODI at 3 months with a mean change of 3.3 points when compared with 15 points for patients with lumbar disc herniation. In conclusion, peri-radicular infiltration of corticosteroids for sciatica does not provide any additional benefit when compared to local anaesthetic injection alone. Corticosteroids do not obviate the need for subsequent interventions such as additional root blocks or surgery.