Effect of Nerve Root Injections on Need for Operative Treatment of Lumbar Radicular Pain, 5-Year Follow-Up

Purpose: We previously published a prospective, randomized, controlled, double-blinded study on the effect of nerve root injections on the need for operative treatment of lumbar radicular pain. We found that selective nerve root injections of corticosteroids were significantly more effective than those of bupivacaine alone in obviating the need for a decompression for up to 13-28 months following injection in operative candidates. In the present study, we wanted to determine if these injections had long-lasting effects, and therefore performed a minimum 5-year follow-up of those patients who had avoided surgery in our initial study.

Methods: Of the 29 patients who had avoided surgical treatment in our previous study, 21 patients responded to a 5-year follow-up questionnaire. All of these patients had initially requested operative intervention and were considered to be operative candidates by the treating surgeon. They had then been randomized and referred to a radiologist for a selective nerve root injection with either bupivacaine alone or bupivacaine with betamethasone. Both the treating physician as well as the patient were blinded to the medication. Of the original 55 patients who had been referred for surgical treatment, 29 had managed to avoid operative intervention.

Summary: Of the 29 patients who had avoided surgical treatment in our previous study, 21 patients responded to a 5-year follow-up questionnaire. Out of the 21 patients who were followed-up at 5 years, 17 had still avoided operative treatment. There was no difference between the bupivacaine alone versus the bupivacaine and betamethasone groups in regards to success in avoiding surgery after 5 years. There were statistically significant decreases in the neurologic symptoms and back pain from baseline to the 5-year follow-up evaluation of all of the patients who avoided operative treatment.

Discussion: Our data suggest that lumbar nerve root injections are not merely a temporizing measure for a short period of time, but that they can actually be curative with effects that last for greater than 5 years. The majority of the patients who managed to avoid an operation in our initial study with a 13-28 month follow-up still managed to avoid surgery at a minimum 5-year follow-up. We believe that this represents definitive proof that nerve root injections have long-term curative effects on lumbar radicular pain. We therefore recommend that all patients who present with lumbar radicular pain without significant neurologic deficits first be offered a nerve root block. To our knowledge, this is the first prospective, randomized study with long-term follow-up on the efficacy of such injections.