A lumbar medial branch nerve block is an outpatient procedure for treating lower back pain.
The lower area of the spine is called the lumbar region. It contains five vertebrae, which connect with each other by the facet joints. The facet joints are found on both sides of the spine.
The medial branch nerves are found near facet joints and they provide nerve supply to the facet joints. When the joints are injured, the medial branch nerves send a signal to the brain that the joint is injured.
You may feel pain if a lumbar facet joint is injured, which may feel like muscle tension. You may have pain in one or more of these areas, and it may last longer than two months.
The common tests that are usually done include such as x-rays or MRIs which may not show if a facet joint is causing pain. The best way to diagnose facet pain is to block the pain signal in a medial branch nerve with a local anesthetic.
During the procedure, the medial branch nerve that supplies the facet joints is targeted. Once the nerve is disrupted, it can no longer transmit pain from the injured facet joint.
Before the Procedure
Do not take any pain medication the morning of the procedure. You should show up to the procedure with your usual pain level.
During the procedure
The physician numbs your skin with local anesthetic. Under X-ray guidance, a thin needle is advance near the facet joint in your lower back. A dye may be injected to make sure the needle is at the correct spot. Once proper position has been confirmed, the nerve is numbed with local anesthetic. The procedure will be repeated for each additional level.
After the procedure
You will be monitored for a half an hour after the Lumbar Medial Branch Nerve Block. When you are ready to leave, the staff will give you discharge instructions.
You will also be given a pain diary. It is important to fill this out because it helps know how the injection is working.
You may feel immediate pain relief and numbness in your lower back for a short period of time after the injection. This may indicate the medication has reached the right spot. You should take it easy for the rest of the day but you can usually return to work the day after the injection.
If your pain goes away for a short time, but then returns, you may be a candidate for radiofrequency ablation (RFA) of the medial branch nerve. This procedure provides a more sustained disruption of pain signals, and longer pain relief.