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.