For patients with lumbosacral radicular syndrome (LRS) due to a herniated disc, there is insufficient evidence to determine whether the treatment with epidural steroid injection (ESI) is clinically relevant, according to a recent study published in The Clinical Journal of Pain. When compared with saline injections and noninvasive conservative treatment, ESIs did not show a clinically relevant difference.
The study consisted of a systematic review and meta-analysis to assess the clinical relevance of ESIs compared with saline injections and noninvasive usual care for adults with LRS due to a herniated disc. Noninvasive usual care includes oral analgesics, bed rest, counseling, or exercise therapy, or a combination of these treatments.
Eligibility criteria included published randomized controlled trials (RCTs) and results of unpublished RCTs in English, Dutch, German, or French. The RCTs had to document 1 or more crucial outcomes for effectiveness of the ESIs, such as function, pain intensity, or health-related quality of life (HRQOL).
A comprehensive search using keywords was conducted in MEDLINE via PubMed, EMBASE, CINAHL, and CENTRAL in 2018 and again in PubMed in 2019. Results of unpublished RCTs were searched through the US National Library of Medicine.
All reviewed articles for this systematic review and meta-analysis were independently assessed for risk of bias. The GRADE approach was used to determine the certainty of evidence and strength of recommendations.
In 2809 searches about ESIs, 17 studies fulfilled the inclusion criteria. They included patients with radicular pain or LRS due to a herniated disc confirmed either by medical imaging or by clinical symptoms. The study split the results into 2 groups: the comparator group, which was either the application of saline injection or noninvasive usual care, and the intervention group, which was the application of the ESI. A total of 10 studies compared the epidural administration of steroids vs saline injections.
A meta-analysis that included 2 studies (n=123) showed a clinically relevant effect in favor of the intervention group, which had more than a 50% reduction in leg pain short-term (risk ratio [RR], 1.92; 95% CI, 1.02-3.61), but the certainty of evidence was very low, and 1 meta-analysis showed high certainty of evidence for back pain intensity short-term. However, it did not show a clinically relevant or a statistically significant effect (mean difference [MD], 4.14; 95% CI, -1.04 to 9.32). Most of the remaining meta-analyses did not have a clinically relevant or statistically significant effect for the application of ESI to treat radicular pain.
To compare ESIs vs usual care, 7 studies were examined; all but 1 had a high overall risk of bias. Of 7 meta-analyses, 1 was used for 15 comparisons; all but 1 of these 22 comparisons showed very low certainty of evidence; 3 comparisons, all from the same study, showed a clinically relevant effect on the physical component scale of the 36-Item Short Form Survey (SF-36) for HRQOL in the short-term (MD, 9.50; 95% CI, 2.37-16.63), medium-term (MD, 14.60; 95% CI, 7.34-21.86), and long-term (MD, 11.90; 95% CI, 4.69-9.11) follow-up.
The leg pain intensity short-term comparison analyzed 2 studies, but it did not show a significant effect (MD, -5.53; 95% CI, -12.94 to 1.87) and was graded as low certainty of evidence. The 14 subgroups did not show clinically relevant effects or statistically significant effects.
These results suggest that there is insufficient evidence that ESIs compared with usual care for patients with LRS are clinically relevant.
The limitations of the study include the assumption that all meta-analyses included patients with LRS due to a herniated disc and only 3 of the included studies reported on a predefined clinical success such as 50% or greater improvement in leg pain.
High quality studies using a predetermined definition of clinical success for comparing ESIs to saline injections and noninvasive usual care are needed to identify potential clinically relevant effects of ESIs. They further state that until these studies are available, they are uncertain as to whether ESIs for the treatment of LRS should still continue.
de Bruijn TM, de Groot IB, Miedema HS, Haumann J, Ostelo RWJG. Clinical relevance of epidural steroid injections on lumbosacral radicular syndrome-related symptoms: systematic review and meta-analysis. Clinical J Pain. 2021;37(7):524-537. doi:10.1097/AJP.0000000000000943