The skeletal consequences of epidural steroid injections: a literature review.

Abstract

Approximately nine million epidural steroid injections (ESIs) are administered annually in the United States to treat radicular back pain. ESIs often provide pain relief and functional improvement. While the overall incidence of adverse events resulting from ESIs is low, their effects on the skeleton are poorly understood. This is an important consideration given the profound skeletal impact of other forms of glucocorticoids. Ovid MEDLINE and PubMed search results since 2010, including older, frequently referenced publications were reviewed. Systemic absorption of glucocorticoids occurs after ESI, which can cause hyperglycemia and endogenous cortisol suppression. The majority of studies investigating the skeletal effects of ESIs are retrospective. Several have found a relationship between low areal bone mineral density (BMD) by dual-energy x-ray absorptiometry and ESI exposure, but this finding is not uniform. Recently a dose-response relationship between ESI exposure and low spine volumetric BMD by computed tomography has been reported. Few studies have investigated the relationship between ESI exposure and fracture risk. Results of these studies are conflicting, and most have not been adequately powered to detect fracture outcomes. While evidence is limited, studies suggest that ESIs may cause bone loss, particularly those investigating volumetric BMD. Larger doses appear to confer greater risk. Further prospective studies are needed to investigate the relationship between ESI and fracture risk. Better understanding of the skeletal consequences of ESIs will help foster strategies to prevent bone loss in the growing population of patients receiving this treatment.