Medial branch nerves are found near the facet joints, which are paired joints at the vertebrae,
with one at each vertebral level. Medial branch nerves carry pain signals, but are involved neither in the movement of any major muscle nor in sensation in the arms and legs. These nerves do control small muscles in the neck, as well as the mid and lower back, although it has been shown that the loss of these nerves do not adversely affect your functionality and activities of daily living. Cervical medial branch nerves are located in the neck; thoracic medial branch nerves are located in the middle to upper back; and lumbosacral medial branch nerves are found in the lower back.
How is the medial branch nerve block done?
The procedure is normally done under local anesthesia, so you may be awake for the
procedure. You may be given a sedative to relax your nerves, if necessary. The operation involves a sterile technique: the surgical site will be prepped with an antiseptic solution, and the area around the site will be wrapped in surgical linen.
The operation begins with the insertion of the needle into the skin. This is done under fluoroscopic (X-ray) guidance, and a small amount of contrast dye is injected to confirm the location of the end of the needle.
In recent years, other methods to guide the placement of the needle have emerged, such as computerized tomography (CT) scans, Magnetic Resonance Imaging (MRI) and ultrasonography.
Once the affected area is reached, the local anesthetic is injected. After the medications have been given time to take effect, you will be asked to perform the motions that usually trigger the pain. A reduction in pain confirms the involvement of the target site. This process will be repeated over all areas that need diagnostic evaluation.
The entire procedure can take anywhere from 15 to 30 minutes, depending on the particular circumstances of your case. You will usually have to stay under observation in the recovery area for at least 30 minutes after the procedure, although you may be sent home within the day.
What are the outcomes of a medial branch nerve block?
While majority of the patients will report improvement after a medial branch nerve block, the Medial Branch Nerve Block Orange Countyprocedure is primarily a diagnostic one, and is not intended to provide long-term relief of the symptoms. Long-term relief can be achieved with more permanent procedures, such as radiofrequency ablation of the affected nerves.
There are always potential risks involved with the procedure. You should be aware that you stand at risk for surgical site infection, intraoperative damage to nerves, muscle and tissue, allergic reaction to the contrast solution, or worsening of pain, among others. However, adverse outcomes are rarely reported, and most patients can easily tolerate this procedure.
Moon JY, Lee PB, Kim YC, Choi SP, Sim WS. An alternative distal approach for the lumbar medial branch radiofrequency denervation: a prospective randomized comparative study. Anesth Analg. 2013;116(5):1133-40. doi: 10.1213/ANE.0b013e31828b35fe.
Derby R, Melnik I, Choi J, Lee JE. Indications for repeat diagnostic medial branch nerve blocks following a failed first medial branch nerve block. Pain Physician. 2013 Sep-Oct;16(5):479-88.
Kim D, Choi D, Kim C, Kim J, Choi Y. Transverse process and needles of medial branch block to facet joint as landmarks for ultrasound-guided selective nerve root block. Clin Orthop Surg. 2013;5(1):44-8. doi: 10.4055/cios.2013.5.1.44.
Derby R, Melnik I, Lee JE, Lee SH. Cost comparisons of various diagnostic medial branch block protocols and medial branch neurotomy in a private practice setting.
Klessinger S. Zygapophysial joint pain in post lumbar surgery syndrome. The efficacy of medial branch blocks and radiofrequency neurotomy. Pain Med. 2013;14(3):374-7. doi: 10.1111/pme.12012.
Roy C, Chatterjee N, Ganguly S, Sengupta R. Efficacy of combined treatment with medial branch radiofrequency neurotomy and steroid block in lumbar facet joint arthropathy.J Vasc Interv Radiol. 2012;23(12):1659-64. doi: 10.1016/j.jvir.2012.09.002.
Sokolof JM, Nampiaparampil DE, Chimes GP. Use of medial branch blocks before radiofrequency ablation for lumbar facet joints. PM R. 2012;4(7):521-6. doi: 10.1016/j.pmrj.2012.06.011.