Medial
Branch- Medial branch nerves are small nerves
that feed out from the facet joints in the spine, and therefore
carry pain signals from those joints. Facet joint injections
are often used to identify a pain source; however, these injections,
and other treatments that may be tried, do not always provide
lasting pain relief. In such cases, it might be beneficial to
confirm that the facet joint is the source of a patient’s
pain so that a radiofrequency medial branch neurotomy may be
considered for longer term pain relief. A medial branch nerve
block temporarily interrupts the pain signal being carried by
the medial branch nerves that supply a specific facet joint.
If the patient has the appropriate duration of pain relief after
the medial branch nerve block, that individual may be a candidate
for a neurotomy. A radiofrequency neurotomy is a type of injection
procedure in which a heat lesion is created on certain nerves
with the goal of interrupting the pain signals to the brain.
A neurotomy should then provide pain relief lasting at least
nine to fourteen months and sometimes much longer. Anatomy of
the Cervical, Thoracic, and Lumbosacral Medial Branch Nerves
Facet joints are pairs of small joints that are situated at
each vertebral level of the spine. Each facet joint is connected
to two medial nerves that carry signals (including pain signals)
away from the spine to the rest of the body:
•
Cervical medial branch nerves are located in a bony groove in
the neck
• Thoracic medial branch
nerves are located over a bone in the mid-back
• Lumbosacral medial branch
nerves are found in a groove in the low back
These
medial or lateral branch nerves do not control any muscles or
sensation in the arms or legs so there is no danger of negatively
affecting those areas. The medial branch nerves do control small
muscles in the neck and mid or low back, but loss of these nerves
has not proved harmful.
