Efficacy of Epidural Steroid Injection in Management of Lumbar Prolapsed Intervertebral Disc: A Comparison of Caudal, Transforaminal and Interlaminar Routes.

INTRODUCTION: Epidural steroid is an important modality in the conservative management of prolapsed lumbar disc and is being used for over 50 years. However, controversy still persists regarding their effectiveness in reducing the pain and improving the function with literature both supporting and opposing them are available.

AIM: To study the efficacy of epidural steroid injection in the management of pain due to prolapsed lumbar intervertebral disc and to compare the effectiveness between caudal, transforaminal and interlaminar routes of injection.

MATERIALS AND METHODS: A total of 152 patients with back pain with or without radiculopathy with a lumbar disc prolapse confirmed on MRI, were included in the study and their pre injection Japanese Orthopaedic Association (JOA) Score was calculated. By simple randomization method (picking a card), patients were enrolled into one of the three groups and then injected methyl prednisone in the epidural space by one of the techniques of injection i.e. caudal, transforaminal and interlaminar. Twelve patients didn't turn up for the treatment and hence were excluded from the study. Remaining 140 patients were treated and were included for the analysis of the results. Eighty two patients received injection by caudal route, 40 by transforaminal route and 18 by interlaminar route. Post injection JOA Score was calculated at six month and one year and effectiveness of the medication was calculated for each route. The data was compared by LSD and ANOVA method to prove the significance. Average follow-up was one year.

RESULTS: At one year after injecting the steroid, all three routes were found to be effective in improving the JOA Score (Caudal route in 74.3%, transforaminal in 90% and interlaminar in 77.7%). Transforaminal route was significantly more effective than caudal (p=0.00) and interlaminar route (p=0.03) at both 6 months and one year after injection. No significant difference was seen between the caudal and interlaminar route (p=0.36).

CONCLUSION: The management of low back pain and radicular pain due to a prolapsed lumbar intervertebral disc by injecting methyl prednisone in epidural space is satisfactory in the current study. All three injection techniques are effective with the best result obtained by transforaminal route.