Periradicular injection is a widely used procedure for treating lumbar radicular pain, but it remains unclear what types of lumbar pathologies respond well to this treatment.

Kanayama et al. reviewed the records of 641 consecutive patients who underwent periradicular injection for degenerative lumbar spine disorders with mean follow-up of 23.4 months. The pathologies included herniated disc in 286 patients, spinal stenosis in 141, degenerative spondylolisthesis in 136, failed back surgery in 24, isthmic spondylolisthesis in 22, degenerative scoliosis in 18, and foraminal stenosis in 14. Outcome measure was whether or not surgery is avoided by using peri-radicular injection. The rate of obviating surgery was determined in each pathology.

Peri-radicular injection obviated surgeries in 331 patients (51.7 %). There were no complications related to the procedure, including neurological deterioration, infection, and haematoma. The rate of obviating surgery was 42.0 % in disc herniation, 52.9 % in degenerative spondylolisthesis, 67.4 % in spinal stenosis, 54.5 % in isthmic spondylolisthesis, 57.1 % in foraminal stenosis, 61.1 % in degenerative scoliosis and 54.1 % in failed back surgery. Poor outcomes were observed in herniated disc with spinal stenosis (17.9 % success), foraminal disc herniation (33.3 %), recurrent disc herniation (18.2 %) and failed back surgery with instability (33.3 %).

This study demonstrated that 51.7 % of patients with degenerative lumbar pathologies were successfully treated by peri-radicular injection. Efficacy was limited in cases of herniated disc with spinal stenosis, foraminal disc herniation, recurrent disc herniation and failed back surgery with instability ¹⁾.