Particulate and non-particulate steroids in spinal epidurals: a systematic review and meta-analysis

Steroids in transforaminal epidural injections are widely used to ease radicular pain in both cervical and lumbar radiculopathy. Concerns have been articulated about the use of particulate steroids for this intervention, as a number of case reports have been published linking them with post procedural paralysis, possibly due to spinal ischaemia secondary to a steroid particulate embolism. Non-particulate, or soluble steroids, are mooted as an alternative; however, their effectiveness relative to particulate steroids has not been conclusively proven.

We review the evidence in the published literature regarding the efficacy of non-particulate steroids in epidural injections compared to particulate steroids, and synthesise it to gauge the qualitative outcomes from level one evidence (visual analogue scales, numerical pain scores and Oswestry Disability Index) from baseline to specified follow up.

The PRISMA guidelines were utilised for this review. An internet search was performed to collate the available literature from medical databases PubMed, EMBASE, Web of Science and the Cochrane library. We used a broad search term [epidural (and) steroid] to ensure a wide capture of articles. No limitations in terms of language or date of publication were implemented. The reference lists of articles included for full text review were searched for any additional primary or review publications.

Four online libraries were searched, with a combined total of 11,353 titles reviewed, not excluding duplicates. Post title abstract and full text review, nine articles were identified as suitable for inclusion for qualitative synthesis. Four of these were suitable for quantitative synthesis, with a total of 300 participants, 147 in the particulate group and 153 in the non-particulate group. Using a random effects model, the pooled standard mean difference of VAS score diminution was not significant between groups (0.31 in favour of particulates, 95 % CI -0.68 to 1.30). From our qualitative synthesis, there was a trend for greater improvement in pain scores within the particulate group. The type of steroid used did not appear to have an effect on the disability score given by patients.

Particulate steroids are not demonstrably better in relieving pain compared to their non-particulate counterparts. In view of the concerns over the safety profile of particulate steroids, it may be prudent to switch to non particulates, or at the very least the dangers and alternatives should be flagged with the patient group as part of a shared decision making process.