Posterior Facet Blocks – Rhizotomy
Posterior facet blocks and facet rhizotomies are treatments used to bring relief to patients suffering from chronic back pain. The facet joints are the flexible spaces between the vertebrae that allow the spine to bend and flex. When problems arise in and around these joints, back pain may occur. When this pain becomes chronic and does not respond well to over-the-counter treatments such as non-steroidal anti-inflammatory drugs (NSAIDs), a physician may suggest a posterior facet block or rhizotomy.
These are both nonsurgical options that are explored when temporary injections and anti-inflammatory medications do not provide sufficient relief. Posterior facet blocks cause a numbing of the nerves in the facet joints of the spine, while a rhizotomy involves the destruction of the nerve responsible for the chronic back pain. These are typically done as outpatient procedures that take about 20 to 30 minutes to perform.
In some cases, the posterior facet block may be used to help diagnose the specific nerve responsible for the pain so that the physician is certain that the correct nerve is being targeted for a rhizotomy. The targeted nerves are used primarily for sensing and are not necessary for a patient to maintain full mobility. Because of the diagnostic and therapeutic uses for these procedures, they can be used as complementary treatments in some cases.
The posterior facet joints are the joints where the vertebrae touch each other on the posterior (back facing) side of the spine. When the joint becomes injured or inflamed, swelling and irritation of the associated nerves may occur. If this pain becomes chronic, a posterior facet block may be performed to help identify the specific joint or to provide temporary relief.
Posterior facet blocks are performed as short outpatient procedures. After the source of the pain has been identified during a consultation with the physician, the injection site is sterilized and a local anesthetic is applied. The needle is guided using either sonogram or with a fluorescent dye visualized by X-ray. An anti-inflammatory steroid is then injected into the inflamed tissue.
The entire procedure typically takes less than 30 minutes to perform. Following the procedure, the patient is monitored for an additional 30 to 45 minutes to ensure that there are no adverse effects. Possible side effects include redness, bleeding, soreness, or numbness localized to the injection site.
After performing a facet block injection, pain relief may last up to several weeks. If the chronic pain returns, a rhizotomy may be necessary. In some cases, the facet block injection will have been performed to better identify the nerves to target for a rhizotomy. In a rhizotomy, the specific nerves transmitting the pain signals are destroyed.
The preparation for a rhizotomy is similar to the preparation for a posterior facet joint injection. The patient arrives at the physician’s office for an outpatient procedure. The skin around the targeted nerve is sterilized and a local anesthetic is applied. Sonographic or X-ray imaging with a fluorescent dye is also used. However, instead of a needle, a rhizotomy uses a small electrode. The electrode is inserted into the tissue alongside the target nerve. When the electrode is activated, it emits radiofrequencies that cause the surrounding tissue to heat, effectively destroying the nerve that it has been placed adjacent to.
The entire procedure takes approximately 30 minutes to complete, which is followed by a brief period of observation to ensure that the patient has no serious side effects. Possible side effects of this procedure include redness, bleeding, infection, and secondary nerve damage. Although the targeted nerve is destroyed, this procedure is not permanent. It is possible for the nerve to grow back and your physician may recommend another rhizotomy after approximately one year has passed.
Posterior facet blocks and rhizotomies are used to treat chronic back pain that does not respond positively to over-the-counter medications and treatments. These treatments provide relief when a nerve associated with a facet joint becomes damaged or inflamed, sending pain signals to the brain.
Any condition leading to damage of the intravertebral discs can lead to problems requiring a posterior facet block or rhizotomy. Facet joint problems include arthritis, age-related degeneration, and acute injuries. Age-related degeneration and arthritis cause a weakening of the facet joint, leading to irritation and inflammation of the tissue in and around the joint.
Facet joints are located between the vertebrae along the entire spine, so pain requiring a posterior facet joint block or rhizotomy can occur anywhere in the body. Pain in the lower body, from the legs through the abdomen, may be caused by lumbar facet joints; pain in the trunk region, such as the chest or back, may be due to problems with thoracic facet joints; pain in the shoulders, neck, or head may be due to the cervical facet joints.
Posterior facet blocks and rhizotomies are complementary outpatient procedures used to treat chronic back pain. A posterior facet block is used to reduce pain and inflammation at the joints of the spine. Although a posterior facet block alone may provide temporary relief, it may also be used to accurately diagnose the problematic nerves so that a rhizotomy may be performed. A rhizotomy destroys the problematic sensory nerve so that it can no longer send pain signals to the brain.
Complications are usually minor, including redness, bleeding, and numbness. In the event that the destroyed nerve regenerates or the pain returns, your physician may recommend a subsequent rhizotomy up to a year later. These procedures allow for a high success rate of pain reduction leading to improved quality of life for many patients.