Related Experiment Video
Updated: Jun 16, 2026
Spinal Sonography for Ultrasound-Guided Lumbar Neuraxial Anesthesia
Published on: January 31, 2025
Ultrasound-Guided Lumbar Nerve Root Hydrodissection: Fluoroscopy-Assisted Evaluation of Injectate Distribution and
Yu Arima1, Yoshiyuki Okamoto1, Kazunari Kuroda1
1Department of Orthopaedic Surgery, Yawata Medical Center, Ishikawa, Japan.
Introduction:
Selective nerve root block is commonly performed under fluoroscopy, but reports of ultrasound (US) guidance remain limited. Although hydrodissection has shown favorable outcomes in peripheral nerves, few studies have evaluated the lumbar nerve root. Therefore, we aimed to evaluate the injectate distribution, reproducibility, safety, and clinical efficacy of US-guided hydrodissection of the lumbar nerve root (US-HNR) using fluoroscopic assistance.
Methods:
US-HNR was performed in 46 patients with lumbar radiculopathy between January and September 2025. A standardized injectate (contrast agent 3 mL, saline 6 mL, and lidocaine 1% 1 mL; total 10 mL) was administered. Distribution was classified into four types under fluoroscopy. The Numerical Rating Scale (NRS), Oswestry Disability Index (ODI), and patient satisfaction were evaluated pre- and postprocedurally.
Results:
Contrast evaluation was possible in 40 patients. Distribution patterns were localized within the periradicular region of the target nerve root in 30%, ipsilateral epidural in 38%, contralateral epidural in 25%, and contralateral nerve root in 8%, suggesting localized spread in one-third of cases. NRS improved significantly from 7.1 to 5.0 at 1 week, 4.2 at 1 month, and 3.8 at 3 months (all p<0.001), with responder rates of 52%, 60%, and 58%. ODI improved from 42 to 32 at 1 month and 28 at 3 months (p<0.01), with responder rates of 54% and 62%. No serious complications were observed. Two experienced transient radiating pain during injection.
Conclusions:
US-HNR was safe and feasible, avoiding radiation and direct nerve puncture. This simple technique showed favorable clinical outcomes and may represent a promising treatment for lumbar radiculopathy.
