Medial Branch Block

The medial branch nerves provide sensation to the facet joints. Each nerve serves two adjacent joints, and each joint has two nerve branches supplying it. Patients with Facet Syndrome can ultimately benefit from Radiofrequency Neurotomy (RFN) if the pain can be proven as originating from the facet joints.

A fluoroscopically-guided local anesthetic injection can prove whether or not pain signals are being sent along the medial branches and therefore help to predict success from Radiofrequency Neurotomy. Since other nearby structures (ligaments as well as a segmented muscle called the Multifidus) are innervated by the Medial Branch Nerves, it is not precise to say that Facet Syndrome is proven if the pain is interrupted by the Medial Branch Block (MBB), but it is reasonable to conclude that destruction of the medial branches by RFN will likely interrupt the pain that the patient is experiencing.



The procedure takes about 5-10 minutes to perform and involves placing a very small diameter needle at the locations at each level where the medial branches run near the vertebral bone. A small amount of local anesthetic is injected at each site and the patient is monitored for the next 30-60 minutes to determine if the pain is blocked. The patient will be evaluated in different positions to see if the typical positions that provoke the pain no longer do so. If the pain is no longer present, the procedure is considered positive, and the patient has a very good probability of responding to RFN as a method of achieving long-term pain relief.

The Medial Branch Block is performed on a separate day from the RFN. The risks of MBB are extremely low, consisting of minor bruising and very rarely infection, as might be seen with any procedure where the skin is punctured by a small needle. The discomfort of the procedure itself is fairly minor.