Effect of Post-Radiofrequency Corticosteroid Injection on the Incidence of Post-Neurotomy Neuritis

Spine-related pain, including cervicalgia, dorsalgia, and lumbalgia, represents a major clinical challenge. Low back pain affects a substantial proportion of the global population and is associated with reduced physical activity and functional limitations in activities of daily living. Facet joint arthropathy is a frequent cause of axial spine pain resulting from repetitive biomechanical stress, local inflammation, and synovitis. Radiofrequency neurotomy (RFN) of the medial branch nerves is an established, minimally invasive interventional modality for managing recalcitrant facet pain.

Although RFN is generally safe, post-neurotomy neuritis (PNN)-a neuropathic condition characterized by burning, dysesthesia, or sunburn-like pain along the treated distribution-remains an important post-procedural complication. Reported incidence rates vary widely, and symptoms may persist for weeks to months. To mitigate PNN, clinicians frequently administer local corticosteroids through the cannula immediately following thermal lesioning; however, existing literature presents conflicting evidence regarding its efficacy, with reported outcomes ranging from significant risk reduction to no apparent protective effect.

This randomized, double-blind, parallel-group controlled trial evaluates whether local corticosteroid administration following RFN reduces the incidence of PNN in adult patients undergoing radiofrequency denervation for cervical, thoracic, lumbar facet, or sacroiliac joint pain at Siriraj Hospital.

Following confirmation of eligibility and written informed consent, enrolled participants are randomized into two parallel groups. All procedures are performed under fluoroscopic guidance by boarded-certified pain specialists using an 18-gauge, 100-mm RF cannula with a 10-mm active tip. Proper positioning is verified via multiplanar fluoroscopy, accompanied by motor and sensory electrical stimulation testing. Lesioning is conducted with a Boston G4 RF Generator, delivering two cycles per target site at 80°C for 3 minutes per cycle.

Following neurotomy, injectates are prepared by an unblinded independent physician to maintain allocation concealment :

• Steroid Group: Receives a local injection of dexamethasone mixed with 0.5% bupivacaine (approximately 1.5 mg/mL/level of dexamethasone).
• Control Group: Receives an equivalent volume of 0.5% bupivacaine alone without corticosteroid.

Both the proceduralist and the participant remain blinded throughout the study. Post-procedural evaluations are conducted at 4 weeks post-intervention via in-person visits or telemedicine to evaluate neuropathic symptoms, pain intensity, functional disability status, and procedural adverse events. An interim analysis is planned when 50% of the target enrollment completes follow-up to monitor efficacy and patient safety.

Inclusion criteria

• Adult patient who aged equal and over 18 years old
• Patient who scheduled for cervical, thoracic, and lumbar medial branch RFN and sacral lateral branch RFN
• Patient who communicated effectively, demonstrated good understanding of questions and provided appropriate responses

Exclusion criteria

• Contraindications to corticosteroids: Patients with a known allergy or hypersensitivity to dexamethasone or other glucocorticoids
• Contraindications to local anesthetics: Patients with a history of severe allergic reactions to amide-type local anesthetics (e.g., bupivacaine)
• Active Infection: Presence of localized infection at the planned injection site or systemic infection (sepsis) that may contraindicate the procedure
• Coagulopathy: Patients with uncorrected bleeding disorders or those unable to safely discontinue anticoagulant/antiplatelet medications according to standard procedural guidelines
• Pregnancy or Lactation: Pregnant or breastfeeding women, due to potential risks associated with radiation (fluoroscopy) and medication exposure
• Recent Corticosteroid Exposure: Patients who have received systemic or local corticosteroid injections at the target site within the past 3 months, which may interfere with the study outcomes
• Unstable Neurological Conditions: Patients with progressive neurological deficits or acute radiculopathy that requires urgent surgical intervention