Medial Branch Blocks (MBBs) are primarily used to alleviate neck and back pain associated with arthritis. These blocks are a minimally invasive and works by reducing inflammation and irritation in the facet joints. If the procedure proves to be beneficial, radiofrequency ablation (rhyzotomy), a more long-term solution, will often be the next step to return the patient back to their normal lifestyle.
Medial branch blocks generally take about 15 minutes to perform. The patient will be asked to lie on their stomach, giving the doctor access to the spine. Fluoroscopy must be used to identify the location of the medial branch nerve. The skin and deep tissues will be anesthetized with local anesthetic. A needle will be inserted with fluoroscopy to the anticipated location of the medial branch nerve, a local anesthetic (Lidocaine or Marcaine) alone or in combination with a long lasting anti-inflammatory ( Depomedrol) will then be injected. The expected results include a reduction of inflammation and irritation and to numb the pain.
There will be two phases of this procedure:
- The first phase is called the local anesthetic phase and can last anywhere from 1-4 hours. During this phase, the medial branch nerve is unable to conduct pain signals from the joint thus giving a sense of relief.
- The second phase is the anti-inflammatory phase. This phase only occurs if steroid is used in the injection. During this phase, pain is relieved by reducing inflammation in the facet joint. This phase should start between days 3-7 after the procedure, and if effective, may last up to 3-4 months and rarely longer.
Patients who benefit from phase I with a short or no phase II are excellent candidates for a radiofrequency rhizotomy (aka ablation) procedure.
Medial branch blocks are typically used as a diagnostic test to see if the pain originates in the facet joint or if another route must be taken to attain relief of neck and/or back pain.