The Dorsal Ramus and Back Pain

Chiropractic Neurologists may be tasked with diagnosing and treating pain that has been recalcitrant to prior forms of intervention.  Overlooking involvement of the lumbar dorsal ramus, and in particular it’s lateral branch, could lead to such a situation. Dorsal Ramus Diagram

This article by Zhou et al (found HERE) provides an excellent review of the anatomy, clinical syndromes and pathogenesis of disorders affecting the Lumbar Dorsal Ramus.  The main take home messages are:

  • The spinal dorsal ramus, arising from the spinal nerve, has both medial and lateral branches, each innervating select tissues.
  • The medial branch supplies the tissues from the midline to the zygapophysial joint line and innervates two to three adjacent zygapophysial joints and their related soft tissues.
  • The lateral branch innervates the tissues lateral to the zygapophysial joint line with pain referral patterns over the flank and into the proximal portion of the buttock.  Thus, the location of pain experienced is often more lateral and below the actual site of involvement.
  • It is possible that pain originating from selective involvement of the lateral branches can be missed if diagnostic and/or therapeutic procedures focus solely on the facet joint and medial branches.

The article goes on to further describe some of the clinical features felt to discriminate between medial, lateral, or combined nerve irritation syndromes and the role of appropriately targeted diagnostic injections.

From a Chiropractic perspective, I found it intriguing how the anatomy and course of the lumbar dorsal ramus seem to render it susceptible to compression, tension, or possible inflammatory irritation.  To this end, the authors also state that structural factors such as vertebral mal-position, facet joint degeneration, capsular irritation, ligamentous hypertrophy, and ossification of the mammillo-accessory ligaments are among the factors often seen in dorsal ramus syndromes.

Such factors would seem to be amenable to our manual procedures.

 

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