The Impact of Corticosteroid Injection Timing on Infection Rates Following Spine Surgery: A Systematic Review and Meta-Analysis

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.

The Impact of Preoperative Spinal Injection Timing on the Postoperative Complications of Lumbar Fusion

OBJECTIVE

To determine the impact of epidural spinal injections (ESIs) on postoperative surgical complications.

METHODS

This retrospective all-payer database analysis identified 202,181 adult patients undergoing one- to three-level transforaminal lumbar interbody fusion (TLIF) from 2010 to 2020. A 1:1 exact matching on comorbidities and demographics was performed, creating 2 cohorts: 1) patients who received an ESI within 90 days of surgery and 2) patients who did not receive an ESI. The primary outcome was surgical complication rates between groups at 30 days postoperatively. For the secondary outcome, patients were stratified based on injection time before surgery: 1-30, 31-45, 46-60, 61-75, and 76-90 days. Logistic regression was performed between groups to identify temporal associations of complication rates. The P value was set to 0.05 for the primary analysis, and the Bonferroni correction was utilized for the secondary outcome.

RESULTS

Exact matching produced 12,491 pairs for analysis. Groups were well-matched on demographics, comorbidities, and fusion levels. The 30-day postoperative rates of surgical complications, hematomas, wound disruptions, or surgical site infections did not differ between groups (P > 0.05). The rate of cerebrospinal fluid (CSF) leak was increased in the ESI group (0.19% vs. 0.09%, P = 0.042). When temporally stratified, patients receiving an ESI within 30 days had significantly higher odds of CSF leak (odds ratio: 4.24, 95% confidence interval: 1.97-9.14).

CONCLUSIONS

Patients who receive an ESI within 30 days of transforaminal lumbar interbody fusion are at an increased risk for CSF leak. While the incidence of CSF leak remains small, it may be advisable to avoid ESIs at least 30 days before surgery for certain patients.

The Anatomy, Technique, Safety, and Efficacy of Image-Guided Epidural Access

Epidural steroid injections have demonstrable efficacy and safety in treatment of radicular pain syndromes; transforaminal access has greater evidence of efficacy than interlaminar approaches. The interventionalist must understand epidural and foraminal anatomy and imaging to insure delivery of medication to the target, the ventral epidural space at the site of neural compression. This obligates pre-procedural planning. When performed with appropriate risk mitigation strategies, epidural injections by either access are safe. For transforaminal access, the use of dexamethasone as the injectate, and infraneural approaches, provides safety advantages.

Preoperative Epidural Steroid Injections and Postoperative Infections After Lumbar or Cervical Spine Surgery: A Systematic Review and Meta-Analysis

Objective

To determine the risk difference and 95% prediction intervals (PIs) for postoperative infections (POIs) associated with preoperative epidural steroid injections (ESIs) in adults undergoing lumbar or cervical spine surgery.

Methods

Comprehensive database searches were conducted from inception dates through December 2023. Inclusion criteria included all study designs involving adults receiving a preoperative ESI before lumbar or cervical decompression or fusion spine surgery. Risk of bias was assessed using a modified tool developed for uncontrolled studies. The summary estimates of risk difference and the corresponding PIs were reported.

Results

A total of 12 studies were included in the systematic review, of which 9 were included in the meta-analysis. Preoperative ESIs within 1 month of lumbar spine decompression or fusion surgery were associated with a 0.6% and 2.31% greater risk of a POI, respectively. In adults ≥65 years of age, ESIs within 1 or 1-3 months of lumbar spine decompression or fusion surgery were associated with a 1.3% and 0.6% greater risk of a POI, respectively. Preoperative ESIs within 3 months of cervical spine fusion were not associated with an increased risk of a POI. The bounds of all corresponding 95% PIs were nonsignificant.

Conclusion

The observations of this study provide summary estimates of risk difference and 95% PIs, which could be used to support shared decision-making about the use of ESIs before cervical or lumbar spine surgery.

Preoperative epidural steroid injections do not increase the risk of postoperative infection in patients undergoing lumbar decompression or fusion: a systematic review and meta-analysis

PURPOSE

Epidural corticosteroid injections (ESI) are a mainstay of nonoperative treatment for patients with lumbar spine pathology. Recent literature evaluating infection risk following ESI after elective orthopedic surgery has produced conflicting evidence. Our primary objective was to review the literature and provide a larger meta-analysis analyzing the temporal effects of steroid injections on the risk of infection following lumbar spine surgery.

METHODS

We conducted a query of the PubMed, Embase, and Scopus databases from inception until April 1, 2022 for studies evaluating the risk of infection in the setting of prior spinal steroid injections in patients undergoing lumbar spine decompression or fusion. Three meta-analyses were conducted, (1) comparing ESI within 30-days of surgery to control, (2) comparing ESI within 30-days to ESI between 1 and 3 months preoperatively, and (3) comparing any history of ESI prior to surgery to control. Tests of proportions were utilized for all comparisons between groups. Study heterogeneity was assessed via forest plots, and publication bias was assessed quantiatively via funnel plots and qualitatively with the Newcastle-Ottawa Scale.

RESULTS

Nine total studies were included, five of which demonstrated an association between ESI and postoperative infection, while four found no association. Comparison of weighted means demonstrated no significant difference in infection rates between the 30-days ESI group and control group (2.67% vs. 1.69%, p = 0.144), 30-days ESI group and the > 30-days ESI group (2.34% vs. 1.66%, p = 0.1655), or total ESI group and the control group (1.99% vs. 1.70%, p = 0.544). Heterogeneity was low for all comparisons following sensitivity analyses.

CONCLUSION

Current evidence does not implicate preoperative ESI in postoperative infection rates following lumbar fusion or decompression. Operative treatment should not be delayed due to preoperative steroid injections based on current evidence. There remains a paucity of high-quality data in the literature evaluating the impact of preoperative ESI on postoperative infection rates.

LEVEL OF EVIDENCE

II.