Evaluation of outcome of facet joints injections in low back pain

Objective: To find out outcome of short- and medium-term therapeutic efficacy of facet joint blocks. Methodology: This descriptive interventional study was conducted in the Department of orthopaedic Khyber Teaching Hospital Peshawar, over a period of nine months January, 2008 to September, 2008. All patients were more than 20 years and less than 70 years with low back pain who were not responding to oral medications and Physiotherapy were included in the study. The facet joint blocks were performed under fluoroscopic guidance. The initial pain response was assessed prospectively using Mac nab and Prolo pain assessment criteria. Additional data, including short-term effect ( 1 week) and medium-term effect (at 3 months), were collected by a structured review interview. A note was made of the results of various imaging studies done in these patients. Just for exclusion inclusion purposes and not for assessment of outcome which was exclusively based on clinical assessment. Results: A positive effect was seen in 37 patients (74%) and 28 (56%) patients in immediate (with in one week) and short term (after 6 weeks) period respectively, while lesser effect was found in 16 patients (33%) at medium term (after 3 months). Conclusion: Facet joint blocks appear to have a beneficial medium-term effect in one third of patients with chronic lower back pain and may therefore be a reasonable adjunct to non-operative treatment. However, outcome appears to depend on clinical, not the morphologic, imaging findings