17 Jan Facet Syndrome: Medial branch blocks and radiofrequency denervation
1) What are facet joints?
- There can be more than one cause of spine pain, including muscles, ligaments, discs, nerve roots, and facet joints.
- The facet joint can be the reason for neck, shoulder, mid back, low back, and leg pain. It can also be a reason for headaches.
- Facet joints are located between backbones in the spine.
- They help keep you from moving the back too much in one direction. The facet joints in the middle back allow you to bend to the side but keep you from rotating.
- The neck joints (cervical spine) at C2-C3 facet joint causes pain the most often, and works to allow you to rotate your head. The C5-C6 joint is the most mobile joint in the neck and second most affected facet joint in the neck.
2) Why do you have pain from facet joints?
- Facet joints receive nerves from the spinal cord and these nerves make it possible for you to feel what is going on in the facet joint.
- The largest branch of these nerves, called the medial branch, is the main nerve that goes to the facet joints. There are two other branches from the nerve root going to the skin and muscles of the back, but the medial branch is the biggest.
- Each facet joint has two medial branches go to it, the medial branch at the same level and the level above.
- Pain can also come from bone and other things inside the joints beside the joint capsule. Whiplash injuries and major trauma to the spine can cause facet joint pain.
3) What is facet disease?
- Facet disease, also known as facet arthropathy, is a degenerative joint disease. However, similar to other degenerative joint diseases, the amount of pain you feel does not tell you how much inflammation or degeneration you have.
- Pain from facet joints is rarely related to a single injury, and is rather related to repetitive strain, disc degeneration, and minor trauma that happens over years. Repeated strain can lead to fluid collection and swelling of the facet joint, and a swollen or larger than normal facet joint can put pressure on a nerve root, causing pain. Because of this, it is more common in the elderly.
- Discs in the back and facet joints work together, so that wear and tear on either can lead to increased strain on the other. The lower back L4-L5 and L5-S1 facet joints usually have the most degenerative disc disease.
- You can also get pain from facet joints after trauma such as rapid deceleration injuries. Whiplash is the most common reason for facet pain after trauma and may be the reason for more than 50% of chronic neck pain after car accidents. Even so, only 13-23% of neck facet pain is related to trauma.
- Facets in the low back are the most frequently affected facets, accounting for about 10-15% of the affected population. However, in patients with chronic neck pain and those with chronic low back pain it is more likely that the facets are the reason for the pain. More specifically, 49-60% of those with chronic, non-radiating neck pain have the pain coming from the facets.
4) How do you diagnose pain from facet joints?
- The diagnosis of facet pain can’t be made from the information you give to your Illinois Pain Institute (IPI) physician, what the doctor finds on the physical exam, x-rays, CT scans, or MRIs.
- The best way to make the diagnosis is with fluoroscopic-guided medial branch blocks.
- Pain referral patterns can give a doctor a clue as to what facets are affected.
- Patients with low back pain from the upper facets often feel pain in the flank, hip, and top side of the thigh.
- Patients with low back pain from the lower facets often feel pain in the side and back of the thigh.
- Patients with neck pain from the upper facets often feel pain in the back of the upper neck and the back of the scalp, while those with neck pain from the middle facets often feel pain in the lower neck and above the clavicles.
- Patients with neck pain from the lower facets often feel pain in the bottom of the neck and the shoulder blade area.
- Imaging such as x-rays and MRIs may not be useful in the diagnosis of facet-related pain as it may not show up. Although the low back facet are the reason for a small percentage of chronic low back pain, CT scans is 40-85% of people show abnormal facets, with this being the case even more so as one gets older. Abnormalities are found just as frequently without pain who get cervical and thoracic MRIs.
- MEDIAL BRANCH BLOCKS / FACET INJECTIONS are used to help doctors diagnose facet joint pain
5) What is a medial branch block?
- A medial branch block involve injecting the nerves that go to the facet joints in order to find out which one is causing pain. It usually needs to be done twice to make sure the results are accurate.
- The patient has to be careful to distinguish between baseline and procedure-related pain.
STEPS FOR A MEDIAL BRANCH / FACET JOINT BLOCK:
- You will lie face down on a table. The skin will be cleaned with soap that may feel cold when applied to the skin.
- A fluoroscope will be used.
- The superficial skin will be numbed with numbing medication, and then a needle will be used to get close to the medial branch nerve.
- Next, numbing medication is injected next the medial branch nerve and then the nerve will be removed.
- About 20-30 minutes after the procedure, whether most of the pain is gone or most of it is still there will help you IPI doctor determine if he or she should go to the next step, which is the radiofrequency denervation (or heating) of the medial branch.
6) What happens after a facet medial branch block?
- Once your IPI physician has found which of the medial nerves is causing the pain, the next step is to perform radiofrequency denervation, which means heating the nerve root in order to stop it from causing pain.
- The procedure is very similar to the medial branch block and involves the same initial steps to prepare the area.
- The heating is done with the active tip of a radiofrequency needle at the location of the nerve.
- Once your IPI physician knows he or she is in the right place based on what is seen on the fluoroscope screen, nerve stimulation is done before the heating. This stimulation may lead to a twitching of the back muscle called the multifidus muscle, which helps the doctor know he or she is in the right place with the needle.
- Before the heating starts, numbing medication is injected through the needle to decrease procedure-related pain.
- Pain relief from radiofrequency denervation can be as short as one month, but most patients get six to twelve months (or longer) of pain relief, after which they need to return to have the radiofrequency procedure repeated after one set of medial branch blocks.
- Post-denervation neuritis, which feels like a sunburn, is the most common complication from radiofrequency denervation and can go away after two weeks.
- Some patients get short periods of numbness or uncomfortable sensations, which are usually minor and go away. There is a 1% chance of increased pain after facet medial branch radio frequency lesioning.