Steroids are potent anti-inflammatory agents, but axial low back pain is not primarily an inflammatory condition and any inflammation that does exist generally cannot be accessed via the spinal canal. The outcomes of ESI for axial low back pain are poor compared to its use in radiculopathy due to disc herniation. Although serious adverse events are rare, catastrophic events can occur and any symptom relief from the injection typically lasts only for a matter of weeks. The inconsequential benefits of ESI for axial low back pain do not outweigh its risks, no matter how small they may be.
Sources:
Benyamin RM, et al. The effectiveness of lumbar interlaminar epidural injections in managing chronic low back and lower extremity pain. Pain Physician. 2012 Jul-Aug;15(4):E363-404. PMID: 22828691.
Choi HJ, et al. Epidural steroid injection therapy for low back pain: a meta-analysis. Int J Technol Assess Health Care. 2013 Jul;29(3):244-53. PMID: 23769210.
Cohen SP, et al. Epidural steroids: a comprehensive, evidence-based review. Reg Anesth Pain Med. 2013 May-Jun;38(3):175-200. PMID: 23598728.