Medial Branch Blocks
Medial branch blocks are sometimes called facet blocks but are slightly different from facet injections. Most physicians and insurance companies consider them diagnostic, meaning they help us determine the cause of pain, rather than a treatment for the pain.
Like facet injections, medial branch blocks are named after the region in which they are performed: cervical, thoracic, or lumbar. A numbing medication is injected in the area of a nerve called the medial branch. These nerves supply sensation to the facet joints, which means if the facet joints are causing pain, the pain should improve after the injection. These blocks are temporary, much like getting numbing at the dentist. That means that even when they work well, medial branch blocks will usually only last a few hours.
Most insurance companies require patients to obtain 80% relief in the specific area of the medial branch block – for instance, just in a small part of the low back – in order to get the long-lasting relief radiofrequency ablation can provide.