The Optimal Needle Placement to Access the S1 Dorsal Root Ganglion for Transforaminal Radiofrequency Treatment.

BACKGROUND

Pulsed radiofrequency (PRF) treatment modulates the dorsal root ganglion (DRG), thereby blocking nociceptive signals. Its success depends on precise electrode placement adjacent to the target DRG. However, proper electrode placement for the S1-DRG is challenging due to uncertainty regarding the S1-DRG's precise location.

OBJECTIVE

Our study aimed to investigate the S1-DRG's location relative to the S1-dorsal foramen (DF) and to develop a technique to facilitate its targeting for PRF application.

STUDY

DESIGN

Human cadaver feasibility study.

SETTING

Cadaver laboratory.

METHODS

Twelve S1-DRGs were dissected. A percutaneous needle passing through the S1-DF targeting the "belly" of the S1-DRG was placed to establish the optimal needle trajectory. The optimal needle skin entry point relative to the posterior superior iliac spine and the needle's caudal and oblique angulations were measured.

RESULTS

In each study cadaver, the S1-DRG was located craniomedially to the S1-DF within the sacral canal. The optimal needle trajectory to the S1-DRG "belly" consistently passed through the inferolateral quadrant of the S1-DF.

LIMITATIONS: Our study's findings are based on anatomical examinations of a limited number of human cadavers and may not fully represent living human anatomy.

CONCLUSION

Approaching through the inferolateral quadrant of the S1-DF maximizes access to the S1-DRG. Placing the needle as described in our study can facilitate PRF treatment of the S1-DRG.