Article Text

other Versions

Download PDFPDF
Anatomical study of the medial branches of the lumbar dorsal rami: implications for image-guided intervention
  1. John Tran1,2,
  2. Philip Peng3 and
  3. Eldon Loh1,2
  1. 1Physical Medicine and Rehabilitation, Western University, London, Ontario, Canada
  2. 2Parkwood Institute Research, Lawson Health Research Institute, London, Ontario, Canada
  3. 3Anesthesiology and Pain Medicine, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
  1. Correspondence to Dr John Tran, Physical Medicine and Rehabilitation, Parkwood Institute, London, Canada; john.tran{at}


Introduction Fluoroscopic-guided radiofrequency ablation of the lumbar medial branches is commonly performed to manage chronic low back pain originating from the facet joints. A detailed understanding of the course of medial branches in relation to bony and soft tissue landmarks is paramount to optimizing lumbar denervation procedures, particularly parallel placement of the radiofrequency electrode. The objectives of this study were to investigate the relationship of medial branches to anatomical landmarks and discuss the implications for lumbar denervation.

Methods Ten cadaveric specimens were meticulously dissected. The origin, course, and relationship of lumbar medial branches to bony and soft tissue landmarks were documented.

Results The medial branches followed the lateral neck of superior articular process deep to the intertransversarii mediales muscle at each lumbar vertebral level. In all specimens, the medial branches coursed laterally on the anterior half of the neck and transitioned from parasagittal-to-medial on the posterior half to reach the mamillo-accessory notch. The mamillo-accessory ligament was found to not occlude the nerve on the posterior quarter of the lateral neck but rather at the mamillo-accessory notch located at the posterior margin of the superior articular process.

Discussion A detailed understanding of the relationship of medial branches to anatomical landmarks is essential to optimizing needle placement for lumbar denervation procedures. The current study suggests that a parasagittal placement, with increased cranial-to-caudal angulation of the electrode, may improve parallel tip alignment with the targeted medial branch and represent a potential alternative to the traditional technique.

  • chronic pain
  • pain management
  • back pain

Data availability statement

All data relevant to the study are included in the article or uploaded as supplementary information.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

Data availability statement

All data relevant to the study are included in the article or uploaded as supplementary information.

View Full Text


  • Twitter @JTNerveGuyPhD, @DrPhilipPeng, @LohEldon

  • Contributors JT, PP, and EL contributed to the experimental design, data acquisition, analysis of data, drafting, and revising the manuscript critically for important intellectual content. JT is responsible for the overall content as guarantor.

  • Funding Funding was provided by the Parkwood Institute Research Specific Endowment (Mary Elizabeth Horney Fellowship in Rehabilitation).

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.