Safety of Epidural Steroid Injections for Lumbosacral Radicular Pain

Abstract

Objective: Epidural steroid injections (ESIs) are a commonly utilized treatment for lumbosacral radicular pain caused by intervertebral disc herniation or stenosis. Although effective in certain patient populations, ESIs have been associated with serious complications, including paralysis and death. In 2014, the US Food and Drug Administration (FDA) issued a safety warning on the risk of injecting corticosteroids into the epidural space. The aims of this article were to review the neurological complications associated with ESIs and to compare the formulations, safety, and effectiveness of commercially available corticosteroids given by transforaminal, interlaminar, or caudal injection. Methods: Serious adverse events associated with ESIs were identified by a search of the FDA Adverse Event Reporting System (FAERS) database. A MEDLINE search of the literature was conducted to identify clinical trials comparing the safety and effectiveness of nonparticulate and particulate corticosteroid formulations. Results: Neurological complications with ESIs were rare and more often associated with the use of particulate corticosteroids administered by transforaminal injection. Among the 10 comparative-effectiveness studies reviewed, 7 found nonparticulate steroids had comparable efficacy to particulate steroids, and 3 studies suggested reduced efficacy or shorter duration of effect for nonparticulate steroids. Discussion: The risk of complications for transforaminal ESI is greater with particulate corticosteroids. Nonparticulate corticosteroids, which are often recommended as first-line therapy, may have a short duration of effect, and many commercial formulations contain neurotoxic preservatives. The safety profile of ESIs may continue to improve with the development of safer, sterile formulations that reduce the risk of complications while maintaining efficacy.

Suspected ischaemic myelopathy following lumbosacral epidural steroid injection in a dog

“…10 On the other hand, non-particulate steroids, such as dexamethasone preparations, contain little to no particles or have particles that are less than 0.5 µm and are freely watersoluble. 7,10 It is hypothesised that particulate steroids have an increased risk of causing embolisation of arterioles in cases of inadvertent intravascular injection, due to particles or particle aggregates blocking small arterioles supplying the neural parenchyma, leading to ischaemia and infarction. 8,10,11,17,18 For example, in an experimental study on a swine model by Okubadejo et al, it was shown that injection of MPA into the vertebral artery resulted in ischaemic brain injury.…”

“…Corticosteroid preparations are frequently used for injection into the epidural space for treatment of radicular pain/radiculopathy in humans and for the non‐surgical management of DLSS in dogs 3,7,11,13 . Injectable corticosteroids can be grouped into two categories based on solubility and/or particle size 10,16 .…”

“…They may also precipitate and crystallise within a hydrophilic environment as they generally have poor water solubility 10 . On the other hand, non‐particulate steroids, such as dexamethasone preparations, contain little to no particles or have particles that are less than 0.5 μm and are freely water‐soluble 7,10 . It is hypothesised that particulate steroids have an increased risk of causing embolisation of arterioles in cases of inadvertent intravascular injection, due to particles or particle aggregates blocking small arterioles supplying the neural parenchyma, leading to ischaemia and infarction 8,10,11,17,18 .…”

“…5 However, in human medicine, although complications following ESI are rare, several reports have presented devastating complications and adverse effects, including cases of paraplegia, quadriplegia, spinal cord infarction and stroke. 7,8 Reports of spinal cord ischaemia, paralysis, permanent blindness and death after ESI have raised concerns about the potential embolisation of particulate corticosteroids. [8][9][10][11][12] To the authors' knowledge, development of ischaemic myelopathy following ESI has not been previously described in dogs.…”

Proposed Canadian Consensus Guidelines on Osteoarthritis Treatment Based on OA-COAST Stages 1–4

“…Complications appear to be rare in veterinary medicine and may relate primarily to sterility and trauma but have also been linked to the formulation (including preservatives and particulation). In human chronic spinal pain management, complications can be severe, and concerns have been raised specifically regarding the use of particulate steroids -like methylprednisoline- when applied epidurally ( 219 ).…”