Dr. Waring’s Concept in Pain Medicine Journal

As featured in the September 2019 issue of Pain Medicine.

Proposed Use of “True” Lateral Fluoroscopic Imaging for Thermal Radiofrequency (RF) Lumbar Medial Branch Neurotomy

Patrick H. Waring, MD, Pain Intervention Center, Metairie, LA, USA

Background: Fluoroscopic “true” lateral imaging is logically necessary for confirmation of proper neurotomy cannula placement prior to initiation of destructive thermal energy. RF neurotomy theory and technique are described fully in the literature, however no detailed explanations exist of “true” lateral lumbar spine image features in relation to final cannula position [1].

Objectives: The purpose of the current study is to determine the anatomical features that when superimposed create a “true” lumbar spine lateral image during lumbar RF neurotomy. The proposed features should allow superimposition and be consistently imaged with standard fluoroscopic movements to confirm correct cannula placement.

Methods: A prospective, observational study was performed in a private practice setting based on the review of lateral images from ten sequential lumbar RF medial branch neurotomy procedures. In this study, the superimposed features proposed for a “true” lateral lumbar spine image included the following: (1) anterior aspects of the superior articular processes, (2) pelvic (iliopectineal) lines, (3) pedicles, and (4) endplates. During cannula placement, the initial image was saved followed by manipulation of the fluoroscope to correct the image to a “true” lateral at each segmental level. All lateral image features were reviewed in the saved images.

Results: A review of procedure notes and images showed that the superimposition of structures was obtained reliably in all cases by movement of the C-arm fluoroscope in the anterior-posterior dimension for features (1) and (2) and in the cephalo-caudal dimension for features (3) and (4).

Conclusion: The use of the proposed features for “true” lateral lumbar imaging may enhance thermal RF lumbar medial branch neurotomy education, quality, and safety as the target structure and final position of the RF cannula are more accurately visualized at each lumbar segment.

References: 1) Bogduk N, editor. International Spine Intervention Society, Practice Guidelines for Spinal Diagnostic and Treatment Procedures, Second Edition, 2013, International Spine Intervention Society, San Francisco, CA.