Facet Joints are innervated or “supplied” by nerves called “medial branches”. These nerves carry the pain signals to the spinal cord and the signals eventually reach the brain, where the pain is noticed.
If the nerves are “blocked” or “numbed”, they will not be able to carry pain sensation to the spinal cord. It is like temporarily cutting off “wires”. Therefore, if the pain is due to facet joint arthritis, you should have relief from pain and stiffness.
Once it is determined that the pain is indeed due to facet joint disease, we can use a procedure called “Radio-Frequency Lesioning” and prevent the conduction of pain information for several weeks to months.
So, the medial branch nerve block is a temporary and diagnostic procedure.