FORAMINAL STEROID INJECTION

Abstract

Introduction Cortisone injection for radicular leg pain may be useful in treating patients with lumbar foraminal pathology based on accurate CT/MRI diagnosis and operator-controlled biplanar fluoroscopy in an angiography suite.

Methods Patient details were collected from operative records and angiography suite records. Demographic data, diagnosis and level of injection were recorded. Low Back Outcome Scores were collected prospectively for most patients. Patients were telephoned and then posted a questionnaire including the LBOS. Taranaki Ethics Committee approval was obtained. Patients were excluded from further analysis, following a single fluoroscopically-controlled foraminal injection of 80 mg triamcinolone for radiculopathy, if further injection or surgery was required.

Results Between 1995 and 2004, 58 patients, all with CT or MRI diagnosis, underwent lumbar foraminal steroid injection. Thirty-seven had disc protrusion (64%) and twenty-one had stenosis (36%). Eighteen (31%) required further intervention (six: repeat injection, 3: discectomy, 8: decompression), in eleven patients with stenosis (52%) and seven patients with disc protrusion (19%). Forty patients had no further intervention. Thirty-two patients (80%) completed follow-up questionnaires, one patient had died, one was lost to follow-up, and six patients declined to complete the questionnaires despite being contacted. The average LBOS for the thirty-two patients who completed the questionnaires was 41.8 (±17.5). Twenty-three patients with pre-treatment LBOS improved on average from 25.1 (±13.5) to 45.9 (±16.1) following injection (p=0.050). The eight patients with stenosis improved on average 24.9 points from 28.8 (±12.3) to 41.6 (±15.9). This is not statistically significant (p=0.95). The fifteen patients with disc protrusion improved significantly from 23.2 (±14.1) to 48.1 (±16.3) at follow-up (p< 0.01). This difference in improvement between the two groups was significant (p=0.016).

Discussion Weiner and Fraser (Weiner BK, et al; J Bone Joint Surg Br. 1997) recommended foraminal steroid injection as the primary treatment for foraminal or extraforaminal disc protrusions, describing 79% patients having long term pain relief with an average follow-up LBOS score of 54 out of a possible 75 points. This present study reports 81% of patients with disc protrusions not requiring further treatment, with an overall average improvement in the follow-up LBOS score to 48. However the results in patients with foraminal stenosis were significantly less satisfactory.