Hybrid vs Fluoroscopy-Guided Interlaminar Epidural Injection in Lumbar Spinal Stenosis

This prospective, randomized clinical trial will compare two imaging guidance strategies for interlaminar epidural steroid injection in adult patients diagnosed with lumbar spinal stenosis. Eligible participants will be randomly allocated into two groups: a fluoroscopy-guided interlaminar epidural steroid injection group and an ultrasound-guided interlaminar epidural steroid injection group with fluoroscopic confirmation of epidural spread (hybrid technique).

All procedures will be performed at a single tertiary care center by experienced clinicians using standardized institutional protocols. In both groups, the interlaminar epidural space will be accessed using a midline or paramedian approach, and the same corticosteroid formulation and injection volume will be administered to ensure treatment consistency.

Procedural outcomes will include total procedure time, fluoroscopy time, radiation dose parameters recorded directly from the fluoroscopy unit, and technical success defined as correct epidural space access with appropriate contrast spread. Radiation exposure will be assessed using dose metrics provided by the imaging system, allowing comparison between the two guidance techniques.

Patient-reported outcomes will be evaluated using validated pain and functional assessment tools at baseline and during routine follow-up visits according to the study protocol. Patient satisfaction will be assessed following the procedure. Adverse events related to the procedure will be documented and monitored throughout the study period.

By systematically comparing these two imaging guidance approaches under standardized clinical conditions, this study aims to clarify whether ultrasound-guided interlaminar epidural steroid injection with fluoroscopic confirmation can reduce radiation exposure while maintaining procedural efficiency, technical accuracy, and clinical effectiveness comparable to conventional fluoroscopy-guided injection.

Inclusion criteria

• Age between 40 and 75 years
• Diagnosis of lumbar spinal stenosis confirmed by clinical evaluation and magnetic resonance imaging (MRI)
• Presence of neurogenic claudication symptoms for at least 3 months
• Inadequate response to conservative treatment, including medication, physical therapy, or exercise
• Numeric Rating Scale (NRS) pain score ≥ 4 at baseline
• Ability to provide written informed consent

Exclusion criteria

• Previous lumbar spine surgery
• Vertebral fracture, spinal malignancy, or history of significant lumbar trauma
• Peripheral vascular claudication or clinically significant peripheral polyneuropathy
• Epidural steroid injection within the past 6 months
• Medical conditions severely limiting ambulation unrelated to lumbar spinal stenosis (e.g., severe cardiopulmonary disease or advanced hip/knee osteoarthritis)
• Pregnancy or breastfeeding
• Coagulation disorders or inability to safely discontinue anticoagulant or antiplatelet therapy according to guideline recommendations
• Known allergy to local anesthetics, corticosteroids, or contrast agents
• Active local or systemic infection
• Body mass index (BMI) > 30 kg/m²