Efficacy of lumbar epidural steroid injections for lumbosacral radiculopathy in individuals with obesity: A retrospective comparative study

Purpose: Obesity, as defined by the CDC, is characterized by a body mass index exceeding 30. Over one third of the world's population is classified as overweight or obese. Furthermore, low back pain is currently the leading cause of disability worldwide. Patients who do not respond adequately to conservative therapy can consider more invasive procedures such as epidural steroid injections (ESI) as treatment for their low back pain. The purpose of this study was to compare the efficacy of lumbar epidural steroid injections for lumbosacral radiculopathy in individuals with obesity as defined by the CDC as BMI >30 as compared to non obese patients. The primary objectives were to examine the difference in pain relief, disability, and function using the Visual Analog Scale, Oswestry Disability Index, and PROMIS 29 profile in obese patients who underwent lumbar epidural steroid injections as compared to non-obese patients for lumbosacral radiculopathy at baseline and 3 months post injection. Results: This study is a retrospective analysis of patients who have undergone lumbar epidural steroid injections for lumbosacral radiculopathy at a single academic center. These patients underwent assessment using validated measurement scales at baseline and 3 months post ESI. Information from the UT Southwestern Spine Center outcomes registry and procedure notes were obtained to analyze pain, disability, functional outcomes from 2016 to 2021. 343 participants took part in the study. The results showed no significant difference in mean levels of ODI, VAS, or PROMIS-29 v1 0.0 scores when comparing values from baseline to 3 months in groups stratified by a BMI of <30 vs a BMI of greater than 30. Furthermore, there was no significant difference in mean levels of ODI, VAS, or PROMIS-29 v1.0 scores when comparing values from baseline to 3 months in groups further stratified by class of obesity: class 1 (BMI 30 to ​< ​35), class 2 (BMI 35 to <40), class 3(BMI 40 or higher). Conclusion: No significant differences were discovered in outcomes in patients undergoing lumbar epidural steroid injections when stratified by BMI or by BMI class. These results have significant clinical implications. Obesity is a known risk factor for the development of low back pain. ESI is a frequently employed method to treat this pain after conservative approaches are exhausted; however, ESI in obese patients typically are associated with more radiation exposure and increased technical difficulty. This study indicates that obesity does not greatly affect the efficacy of lumbar epidural steroid injections. Obesity should not be a strict contraindication to lumbar ESI. In addition, the results can guide clinicians in a well-informed shared decision-making discussion with obese patients regarding the risks and potential benefits of lumbar ESI.