Tehran University of Medical Sciences Archives of Anesthesiology and Critical Care 2423-5849 0 0 2026 10 16 1634 1634 Mehrshad Namazi Pain Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran. Alireza Khajenasiri Pain Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran. & Department of Anesthesiology and Critical Care, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran. Ebrahim Espahbodi Pain Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran. & Department of Anesthesiology and Critical Care, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran. Hossein Majedi Pain Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran. & Alan Edwards Pain Management Unit, Department of Anesthesia, Montreal General Hospital, McGill University, Montreal, Canada. Babak Eslami Pain Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran. & Department of Anesthesiology and Critical Care, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran. Reza Atef-Yekta Pain Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran. & Department of Anesthesiology and Critical Care, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran. 2026 05 08 2026 06 22 Background: Chronic lumbosacral radiculopathy involves persistent radicular pain associated with mechanical and inflammatory processes. Caudal epidural steroid injections (ESIs) are commonly used for chronic radicular pain. Hyaluronidase has been proposed as an adjunct to facilitate epidural spread, but evidence regarding its incremental benefit remains limited. Methods: In this single-blind randomized controlled trial, 40 patients with chronic lumbosacral radiculopathy due to lumbar disc protrusion and/or lumbar canal stenosis were randomly assigned to two groups. Group A received 10 mL of 5% saline, followed by 10 mL of 1% ropivacaine and 40 mg dexamethasone. Group B received 5 mL of 5% saline followed by the same dose of 1% ropivacaine and dexamethasone plus 5 mL containing 1500 U hyaluronidase. All procedures were performed under fluoroscopic guidance. The primary outcome was the change in pain intensity measured by the Numeric Rating Scale (NRS) at 3 months. Secondary outcomes included sleep disturbance, sitting and standing intolerance, neurogenic claudication assessed by walking distance, lower extremity muscle strength, and procedure-related adverse events. Results: Group B had a greater reduction in NRS at 3 months than Group A (between-group mean difference 1.60, 95% confidence interval [CI] 0.45–2.75; P = 0.009). Sleep disturbance improved more in Group B, with a 54.3% reduction at 3 months (P = 0.012). Neurogenic claudication also improved more in Group B, with 75% of patients able to walk ≥300 meters at 3 months versus 30% in Group A (P = 0.010). Conclusion: Adding hyaluronidase to fluoroscopy-guided caudal epidural steroid injection was associated with greater pain reduction and improvement in selected functional outcomes over 3 months. These findings warrant confirmation in larger randomized trials with longer follow-up and validated disability measures. https://aacc.tums.ac.ir/index.php/aacc/article/view/1634