Medial Branch Block
The purpose of medial branch blocks is to ‘numb’ suspected facet joints that are causing painful conditions. In this way the blockade will reduce or eliminates the pain of damaged facet joints by disrupting the medial branch nerves that carry the pain signals to the brain. It is performed using local anesthetic to reduce pain with anti-inflammatory steroid added if inflammation of the joint is also a contributing factor.
Conditions that are well suited for this treatment are the same ones that can be treated by cervical/lumbar medial branch nerve rhizotomy. These include neck or back pain that is non radicular, motion sensitive, or associative with facet joint types of pain sources. Cervicalgia, lumbago, degenerative joint pain, spondylosis, neck or back injury and some whiplash injuries are all treated with medial branch blocks and later facet radiofrequency rhyzitomy if indicated.
This procedure is usually indicated for mostly non radicular pain. Medial branch nerves are involved in pain coming from the facet joint. This can include facet arthropathy, facet joint or disc degeneration and the facet joint syndrome. The same nerves are then indicated for the rhyziotomy procedure in order to prolong the pain relief. The area ‘burned’ is usually around 10 mm and the nerve can grow back with pain recurring after a prolonged period of pain relief.
What to Expect
Patients usually have injections of the medial branch nerves done on an outpatient basis using fluoroscopy or other image guidance for proper needle placement. Because the nerves give off branches both above and below the joint, there usually are three or four needles used to block all the contributing nerves of the suspected levels. The skin will be numbed and the needles placed with sometimes small amounts of contrast used to confirm placement. Then a solution of steroid and/or local anesthetic is injected in small amounts. The effects of the local anesthetic will wear off before the steroid takes full effect such that the immediate effects of the anesthesia may wear off and the pain recur prior to the longer lasting effect of the steroid.
Although pain may increase for the first week after the procedure, the patient usually has full relief from pain within a month. Successful radiofrequency neurotomies can last longer than steroid block with local anesthesia injections. Medial branch nerve blocks are usually done to both treat and diagnosis the cause and effect of the suspected pain condition. For a return of the pain the blocks can be repeated or a rhizotomy can be done on the same nerves.