FAQ’s on Medial Branch Nerve Block in Philadelphia

Along the posterior (back) region of the spinal column lies the facet joints, which are spaces where the vertebrae come together. These can be a source of pain with advanced arthritis and spinal disease. Each facet joint has two small branches of nerves that spur from the spinal cord. A medial branch block is used to interfere with pain signal transmission from these nerves.

What is the purpose of a medial branch block?

When structures of the spine weaken with age, injury, or wear-and-tear, the facet joints become enlarged (hypertrophic). This leads to significant back pain. The medial branch block is used to diagnose and treat spinal disorders. The procedure can be repeated several times each year, if one injection does not provide effective pain relief. Conditions treated with this procedure include spinal arthritis, degenerative disc disease, spinal stenosis, and radicular pain.

How do I prepare for the medial branch block?

Before the procedure, the doctor will discuss the risks and benefits with you, and have you sign a consent for services form. You must arrange to have someone to drive you home, and notify the doctor of all medications you are taking. Blood-thinning agents must be held for 3-7 days before the procedure. When you arrive at the medical facility, a nurse will place an IV catheter in your arm to give you sedation and necessary fluids and medications.

What happens during the medial branch block procedure?

The doctor will position you face down on the procedure table, and cleanse the back with an antiseptic solution. Using fluoroscopy (x-ray guidance), a needle is inserted near the nerves. Several levels are injected at one time if necessary. When a long-acting anesthetic is instilled onto the nerves and relieves pain, the diagnosis of facet joint pain is made. Once the doctor confirms the specific level of nerve involvement, radiofrequency energy can be used to destroy the nerves.

What happens after the procedure?

Immediately after the procedure, you will be monitored by a nurse for 20-30 minutes. It is normal to experience tenderness at the injection site, as well as leg or arm numbness and weakness (temporary side effects). You are permitted to resume normal activities as tolerated, but should rest for the remainder of the day. In addition, do not use heat for 1-2 days, and no soaking in water (pool, tub, spa) for the remainder of the day. The effects of the anesthetic will occur within a few hours, but it may take several weeks to achieve effects from the radiofrequency ablation.

What are the risks and side effects of the medial branch block?

The pain management specialist will discuss the various complications and risks associated with the medial branch block. These include nerve damage, blood vessel injury, bleeding, and infection. Rare risks include bladder/bowel dysfunction, kidney failure, and paralysis. Side effects of this procedure depend on the medication used, and include insomnia, fluid retention, elevated blood sugar, and soreness at the injection site.

Is the medial branch block effective?

The success of the medial branch block varies from patient to patient. Inflamed or irritated facet joints cause 15-35% of lower back pain. The medial branch nerves are associated with conditions that lead to chronic back discomfort. In recent clinical studies, 73-89% of patients reported pain relief that lasted for more than 2 weeks after this block. In one research report, 68% of participants reported effectiveness for 6 months.


Anand, S., Muhammad, S.SM. (2007). Patients’ response to facet joint injection. Retrieved from: http://www.actaorthopaedica.be/acta/download/2007-2/13-Anand%20et%20al.pdf

Boswell MV, Trescot AM, Datta S, Schultz DM, Hansen HC (2007). Interventional techniques: evidence-based practice guidelines in the management of chronic spinal pain. American Society of Interventional Pain Physicians. Pain Physician, 10(1):7-111 PMID: 17256025

Manchikanti L, Manchikanti KN, Manchukonda R, Cash KA, Damron KS, Pampati V, McManus CD (2007). Evaluation of lumbar facet joint nerve blocks in the management of chronic low back pain: preliminary report of a randomized, double-blind controlled trial: clinical trial NCT00355914. Pain Physician, 10(3):425-40 PMID: 17525777