Are fluoroscopic caudal epidural steroid injections effective for managing chronic low back pain?

This study sought to determine the efficacy of fluoroscopic caudal epidural steroid injections as a conservative treatment in patients with presumably chronic lumbar discogenic pain.

Epidural steroid injections have been used in the treatment of lumbar radicular pain with success. However, despite their widespread use, there are few, if any, reports of the efficacy of Epidural steroid injections in patients with predominantly axial lumbar pain. Prior studies have been limited by the use of non-fluoroscopically guided injections and failing to apply a specific injection approach (i.e. transforaminal, interlaminar, or caudal) to a specific patient population.

Ninety-seven patients with chronic axial low back pain and Magnetic Resonance Imaging evidence of disc pathology without stenosis were selected from chart review. All patients received at least one fluoroscopically guided caudal epidural injection with 12 mg of betamethasone and 8 cc of 0.5% lidocaine. Collected follow-up information included Roland-Morris Disability, Visual Numeric Pain Scale, and patient satisfaction scores.

Only nineteen patients (23%) were determined to have a successful long- term (> 1 year) outcome and 65 (77%) were deemed failures. Average follow-up was 28.6 +/- 15.6 months. Successes were found to differ significantly from failures in pre-injection pain scores and patient satisfaction. Overall patient satisfaction was 45%.

At greater than two year follow-up, the efficacy of fluoroscopically guided caudal epidural steroid injections in patients with chronic lumbar discogenic pain is poor. Patient satisfaction exceeds the reported rate of efficacy. Patients responding to injection have significantly lower pre-injection pain scores.