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Optimizing S1 nerve root block using three-dimensional computed tomography imaging: Identifying the ideal
Noritaka Suzuki1, Toshiaki Kotani2, Shuhei Ohyama3
1Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan; Department of Orthopedic Surgery, Seirei Sakura Citizen Hospital, 2-36-2 Ebaradai, Sakura-City, Chiba, 285-0825, Japan.
This study found the reference position angle (RPA) closely approximates the tunnel view angle (TVA), offering an optimal fluoroscopic angle for S1 nerve root block (S1NRB). Anatomical landmarks predict S1 neural foramen position regardless of patient characteristics.
Area of Science:
- Pain Management
- Radiology
- Anatomy
Background:
- S1 nerve root block (S1NRB) is crucial for diagnosing and treating lower limb pain.
- Obscured S1 neural foramen visibility complicates S1NRB procedures.
- Standardizing S1NRB technique requires identifying optimal fluoroscopic angles.
Purpose of the Study:
- To identify the optimal fluoroscopic angle for S1 nerve root block (S1NRB).
- To standardize S1NRB technique using three-dimensional (3D) computed tomography (CT) images.
- To evaluate the predictability of S1 neural foramen position using anatomical landmarks.
Main Methods:
- Analysis of 3D CT images from 101 patients with lumbar degenerative diseases.
- Definition and measurement of reference position angle (RPA) and tunnel view angle (TVA).
- Evaluation of S1 neural foramen position relative to S1 spinous process and sacroiliac joint landmarks.
Main Results:
- Mean RPA was 32.4° ± 6.4° and mean TVA was 34.0° ± 6.2° (r=0.897, p<0.0001).
- S1 neural foramen position was consistently predictable using landmarks, irrespective of sex or body size.
- The S1 neural foramen was typically located 0-4 mm caudal to the S1 spinous process.
Conclusions:
- The reference position angle (RPA) is a reliable indicator for optimal S1NRB fluoroscopic guidance.
- S1NRB technique can be standardized using RPA and predictable anatomical landmarks.
- This approach enhances S1NRB safety and efficacy in managing lumbosacral pain.
