The association between preoperative epidural steroid injections and postoperative cervical and lumbar surgical site infections: A systematic review and meta-analysis.

BACKGROUND

Is there a statistically significant association between preoperative epidural steroid injections (ESI) and postoperative cervical and lumbar spinal surgery infections (SSI)?

METHODS

A systematic review and meta-analysis was completed of patients 18 years or older who underwent elective cervical or lumbar spinal surgery. Those who underwent surgery with preoperative ESI were compared to those without. We assessed for differences in postoperative SSI incidence. Electronic literature databases were searched through October 2022. Peer-reviewed publications that included raw data regarding epidural exposure and non-exposure were included. Case reports, case series, abstracts, editorials, or publications that did not include raw data were excluded. Odd's ratios (OR) were calculated from the raw data collected. Meta-analysis was done using RevMan v5 with a fixed effects model.

RESULTS

We identified 16 articles for inclusion. When not controlling for the type of surgery and time from ESI to surgery, there was a statistically significant OR between preoperative ESI and postoperative SSI. The association persisted when the ESI was performed within 30 days or 31-90 days of the surgery. No association was discovered when evaluating only cervical spine surgeries. The evidence is assigned a "moderate" GRADE rating.

CONCLUSIONS

Our analysis shows a small, time-dependent, statistically significant association between preoperative ESI and postoperative lumbar SSI may exist. However, the OR produced, while statistically significant, are close enough to 1.0 that clinically, the effect size is "small." The number needed to treat for an ESI in the appropriate clinical setting is, at worst, 3. The number needed to harm, meaning the number of patients who undergo an ESI at any time before their spine surgery and then develop a SSI, is 111 patients. Ultimately, the surgical sparing potential from an ESI outweighs the SSI risk based on our findings.