Comparing the clinical outcomes of lumbar transforaminal vs interlaminar epidural steroid injections in a registry cohort.

Background: Transforaminal and interlaminar approaches are both common means of performing epidural steroid injection. Comparative effectiveness data on outcomes of these approaches is available but has yielded mixed results. Objective: Compare the effect of transforaminal vs interlaminar delivery of epidural steroids on patient-reported pain severity. Design: Retrospective Cohort Study. Methods: A retrospective review of prospectively collected interventional spine procedure registry data between December 2011 and July 2017 from a single academic medical center. Those who received epidural steroid injections and had prospectively collected index pain data (11-point Numeric Rating Scale [NRS]) recorded in the patient's chart prior to the procedure and at a 3 month follow up appointment were included. The outcome of interest was ≥50% reduction in pain as measured using a NRS for back and/or leg pain. To evaluate true predictive odds of success, multivariable logistic regression modeling was used to determine the odds of achieving improved pain. Results: Of the 73 patients included in the study, 61 (84%) reported radicular pain, 49 (67%) reported back pain, and eleven (15%) had symptoms consistent with claudication, pain characteristics were not mutually exclusive. Fifty-one (70%) underwent transforaminal epidural steroid injection, while 22 (30%) underwent interlaminar injection. When claudication and radicular pain groups were combined into a single "leg pain" category (n = 66), 26/46 (57% 95% CI 41-71%) patients undergoing transforaminal and 6/20 (30% 95% CI 12-54%) patients undergoing interlaminar injections achieved ≥50% leg pain reduction on NRS (p = 0.048). Transforaminal epidural steroid injections were associated with higher odds of ≥50% reduction in leg pain in both the unadjusted model (OR 3.2, p = 00.034) and after adjustment for presence of radicular pain on presentation and the type of steroid used (OR 3.6, p = 0.042). Conclusion: In this clinical practice registry, patients treated with transforaminal epidural steroid injection were more likely to achieve ≥50% reduction in radicular or neurogenic/claudicatory leg pain compared to those treated with interlaminar epidural steroid injection.

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.

Current trends in the technical performance of lumbar zygapophyseal joint interventions.

Objective: To survey how interventional pain physicians are currently performing lumbar facet interventions, with an emphasis on fellowship training. Design: Survey Study. Methods: An online electronic survey disseminated via Research Electronic Data Capture (REDCap) software to current and expired attending physician members of the Spine Intervention Society (SIS). Responses were stratified by fellowship training type: ACGME Pain Medicine (APM), ACGME Sports Medicine (ASM), Interventional Spine and Musculoskeletal Medicine (ISMM), or None. Results: As a whole, a majority of respondents indicated on independent questions they require 2 diagnostic medial branch blocks (MBBs) performed with 0.5 â€‹cc or less of anesthetic to result in at least 75% pain relief before proceeding with a radiofrequency neurotomy (RFN), performed via parallel approach with 18g or larger needle and 10 â€‹mm active tip and a lesion of at least 80-85° C and 90-119 â€‹s of duration. Statistically significant differences as stratified by APM vs ISMM fellowship training included: the use of corticosteroids at the time of RFN (43/79 (54.4%) vs 16/63 (25.4%), typically treating 3 segments or more 22/79 (27.8%) vs 7/73 (9.6%), and MBB volume injectate of ≥ 1 â€‹cc 22/79 (27.8%) vs 7/63 (11.1%) respectively. Conclusions: There is largely agreement upon the technical performance of lumbar facet interventions by members of SIS. Physicians who completed an APM fellowship were more likely to report using corticosteroids at the time of RFN, using higher anesthetic volumes and treating 3 or more spinal segments.

Elucidating the potential of crude cell extracts for producing pyruvate from glucose.

Living systems possess a rich biochemistry that can be harnessed through metabolic engineering to produce valuable therapeutics, fuels and fine chemicals. In spite of the tools created for this purpose, many organisms tend to be recalcitrant to modification or difficult to optimize. Crude cellular extracts, made by lysis of cells, possess much of the same biochemical capability, but in an easier to manipulate context. Metabolic engineering in crude extracts, or cell-free metabolic engineering, can harness these capabilities to feed heterologous pathways for metabolite production and serve as a platform for pathway optimization. However, the inherent biochemical potential of a crude extract remains ill-defined, and consequently, the use of such extracts can result in inefficient processes and unintended side products. Herein, we show that changes in cell growth conditions lead to changes in the enzymatic activity of crude cell extracts and result in different abilities to produce the central biochemical precursor pyruvate when fed glucose. Proteomic analyses coupled with metabolite measurements uncover the diverse biochemical capabilities of these different crude extract preparations and provide a framework for how analytical measurements can be used to inform and improve crude extract performance. Such informed developments can allow enrichment of crude extracts with pathways that promote or deplete particular metabolic processes and aid in the metabolic engineering of defined products.