Efficacy of Lumbar Transforaminal Epidural Steroid Injections for Lumbosacral Radiculopathy in Individuals with Spine Surgery: A Retrospective Comparative Study

Abstract

Introduction: Transforaminal epidural steroid injections (TFESI) have demonstrated their efficacy in both short-term and long-term treatment of radicular pain with their targets being the anterolateral epidural space and dorsal root ganglion. Although the evidence for transforaminal injections in treating radiculitis secondary to discherniation and lumbar stenosis is strong, evidence is limited regarding its effect on axial pain and in patients with failed back surgery syndrome (FBSS). Methodology: 61 patients were registered in this retrospective comparative study who underwent lumbar TFESI for lumbosacral radiculopathy from March 2021 to March 2022. All patients were assessed for difference in pain relief, disability and functional outcome at baseline and at the time of follow up using NRS, ODI & PROMIS. As a secondary objective the patients were divided into two groups those with previous history of spine surgery (Group A) and non-operated patients (Group B) to Compare the mean levels of pain relief, functional outcome and disability in spine surgery patients compared to non-operated patients. After Ethical committee approval and informed consent from patient baseline scores (NRS, ODI & PROMIS) were accessed from the MRD and follow up scores were obtained by sending a questionnaire across to the patient by email. The average follow up time was 1 year and 4 months (Mean). Results and Observations: A minimum clinically important difference (MCID) of >2.0 was selected for the change in NRS to further determine the proportion of responders who experienced a clinically significant reduction of pain. Success in achieving MCID is defined by ≥3 t score change for all PROMIS instruments. Success in achieving MCID for ODI is defined as at least 30% score change at follow up from baseline score. There is no significant difference in pain relief, disability improvement, functional outcome as assessed by NRS, ODI & PROMIS between the two groups. In this study the success in achieving MCID for NRS was 70% in Group A and 63% in group B and overall 67% indicating that total 41 patients (67%) had significant reduction in NRS after TFESI. In this study success of achieving MCID for ODI was 38.7% among Group A which was comparable to 23.3% among Group B and the difference was not statistically significant. The overall success of achieving MCID for ODI was total 19 patients (31.1%) indicating only 31% patients had significant improvement in disability post TFESI. There is no significant difference in functional outcome as assessed by PROMIS instruments between the two groups. For PROMIS PF, PI, SD the success of achieving MCID was greater than 70% overall and for both the groups. Conclusion: There is no doubt regarding the efficacy and therapeutic effect of TFESI in axial lumbosacral pain/radicular pain in non-operated patients. This study demonstrates the success rate of TFESI in spine surgery patients (FBSS) as well by utilizing PROMIS as an outcome measure and by use of a control group demonstrating improved Physical Function, less pain interference & improved sleep.