Systematic review of the effectiveness of caudal epidural steroid injections in the treatment of chronic low back or radicular pain

Objective: Determine the efficacy, effectiveness, and safety of fluoroscopically- or ultrasound-guided caudal epidural steroid injections (ESIs) with or without catheter placement for the treatment of chronic low back (CLBP), radicular pain, and/or chronic post-surgical back pain (CPSBP). Design: Systematic review. Population: Adults ≥18 years with CLBP, radicular pain, or CPSBP ≥3 months. Intervention: Fluoroscopically- or ultrasound-guided caudal ESI with or without a catheter including epidural neuroplasty. Comparison: Sham, placebo procedure, active standard care treatment, or none. Outcomes: The primary outcome was the proportion of individuals with reduction of pain by ​≥ ​50%. Secondary outcomes included functional improvement, analgesic use, subsequent spinal surgery, healthcare utilization, and mean improvement in pain. Reported adverse events were also cataloged. Methods: Four reviewers independently assessed publications before January 2, 2022 in PubMed, Ovid MEDLINE, and Scopus. Quality of evidence was evaluated using the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) framework. Results: Of 364 records screened, 23 publications met inclusion criteria. The success rates for the primary outcome could only be extrapolated from one study. Another study used a composite improvement scale that included pain and functional outcomes. The reported success rates in these two studies ranged from 40 to 58% at three months, 25%–67% at six months, and 58%–61% at one year. Data on secondary outcomes were limited; however, rates of functional improvement as measured by mean improvement in Oswestry Disability Index (ODI) ranged from 2% to 55%. Conclusion: There is moderate-quality evidence that caudal ESIs using an in-dwelling catheter for two days is an effective treatment for pain and dysfunction associated with disc herniation with radicular pain and for CPSBP at three, six, and 12 months. There is low-quality evidence supporting the effectiveness of other caudal ESI techniques for pain and dysfunction associated with central lumbar spinal stenosis with neurogenic claudication, discogenic CLBP, and CLBP without disc herniation or radiculitis.