[Injection into the lumbar vertebrae in chronic low back pain. Results in 206 patients].

Facet syndrome is an apparently common although not readily identifiable cause of low back pain. To evaluate the efficacy of corticosteroid facet joint injection for the treatment of low back pain, we retrospectively studied 206 patients with low back pain ascribed to facet syndrome. Effectiveness was evaluated on the basis of a clinical score and of a questionnaire completed 10 to 34 months after treatment. Success rate was 53.9% according to the clinical score (23.3% excellent results and 30.6% average results) and 41.74% according to the questionnaire. Results were better in patients who were not gainfully employed and had a negative history for occupational injury and surgical discectomy. Success rates in earlier studies varied from 22% to 76% in the short term and from 8% to 62% in the long term. These broad ranges denote substantial variations in evaluation criteria and patient selection. Only two placebo-controlled trials have been performed. There is a need for a prospective study with strict inclusion criteria and appropriate evaluation criteria taking quality of life into account to determine the role of facet joint injection in low back pain.