SELECTIVE NERVE ROOT INFILTRATION IN THE LUMBAR SPINE: A PROSPECTIVE OUTCOME STUDY WITH 5 YEAR RESULTS

Introduction: There is little evidence for the long term efficacy of selective nerve root injections (SNRI) in the control of lumbar radiculopathy. We report the 5 year results of a prospective study of SNRI in the lumbar spine. Methods: All patients considered to be operative candidates by two treating surgeons (JMP and DJS) with unilateral/bilateral radicular leg pain were included. Patients had a mean history of radicular symptoms of 12.8 months (4 months–3 years). All had an SNRI under image intensifier control with local anaesthetic and steroid. Each patient was evaluated pre-operatively, 2 months, 6 months, 1 year, 2 year and 5 years with VAS and ODI scores. Results: Sixty-two consecutive patients were reviewed. The mean age of patients was 54.5 years (36–80 years). 92 injections were performed. Symptoms were caused by degenerative disease (n=32), disc herniation (n=25), and previous surgery (n=3). The ‘disc’ group was significantly younger than ‘degenerative’ group (49.4 yrs vs. 58.4 yrs; p=0.004). There were significant improvements in low back pain (LBP), leg pain (LP), and ODI at 2 months in all patients. At 5 years the disc group did better with both leg and back pain; whilst there was only a significant reduction in leg pain in the degenerative group. Over 90% (n=56) of patients had no operative intervention; a subgroup of 8 had further injections. Within the degenerative group, ODI and VAS deteriorate early on indicating that a second injection option in this group may be worthwhile. Conclusion: At five-years, most patients avoid operative treatment because of improved symptom control with SNRI. Regression analysis showed “duration of symptoms” and “age” is predictive of good outcome at one year post SNRI, but gender and, diagnosis are not.