Combined Ultrasound and Fluoroscopy versus Ultrasound versus Fluoroscopy-Guided Caudal Epidural Steroid Injection for the Treatment of Unilateral Lower Lumbar Radicular Pain: A Retrospective Comparative Study

Background and Objectives: This study aimed to evaluate the mid-term effectiveness and safety of a combined ultrasound (US) and fluoroscopy (FL)-guided approach in comparison to US-guided and FL-guided caudal epidural steroid injections (CESI) for treating unilateral lower lumbar radicular pain. Materials and Methods: A total of 154 patients who underwent CESI between 2018 and 2022 were included. Patients were categorized into three groups based on the guidance method: combined US and FL (n = 51), US-guided (n = 51), and FL-guided (n = 52). The study design was retrospective case-controlled, utilizing patient charts and standardized forms to assess clinical outcomes, adverse events, complications during the procedures. Results: In all groups, Oswestry Disability Index and Verbal Numeric Scale scores improved at 1, 3, and 6 months after the last injection, with no significant differences between groups (p < 0.05). The treatment success rate at all time points was also similar among the groups. Logistic regression analysis showed that injection method, cause, sex, age, number of injections, and pain duration did not independently predict treatment success. Blood was aspirated before injection in 2% (n = 1), 13.5% (n = 7), and 4% (n = 2) of patients in the combined US and FL groups, FL-guided groups, and US-guided groups, respectively. Intravascular contrast spread was detected in one patient in the combined method groups and seven in the FL-guided groups. Conclusions: When comparing pain reduction and functional improvement, there was no significant difference between the three methods. The combined method took less time compared to using FL alone. The combined approach also showed a lower occurrence of intravascular injection compared to using FL alone. Moreover, blood vessels at the injection site can be identified with an ultrasound using the combined method. Given these advantages, it might be advisable to prioritize the combined US- and FL-guided therapy when administering CESI for patients with unilateral lumbar radicular pain.