Medial Branch Block
The facet joints at the posterior aspect of the spine are often a source of acute or chronic neck, thoracic and low back pain. Facet joint injections performed under x-ray guidance are often used to identify a facet joint(s) as pain source, however these injections, and other treatments that may be tried, do not always provide lasting pain relief.
Another way to see if the facet joints are a primary pain generator in a particular patient is to temporarily block the nerve fibers to these small joints at the back of the spine. The medial branch nerves are small nerves that feed out from the facet joints in the spine, and therefore carry pain signals from those joints. Blocking the medial branches with local anesthetic is often 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 (also called RF ablation) is a type of injection procedure in which a heat lesion is created on certain nerves (in this case the medial branches) 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.
Figure 1: Cervical Medial Branch Block
Figure 2: Lumbar Medial Branches
Figure 3: Lumbar Medial Branch Block
