What Are Facet Joint Injections And Medial Branch Blocks?

Lumbar facet syndrome, neck pain, back pain, and other pain related conditions can lead to facet degeneration. Patients suffering from facet degeneration are often referred for facet joint injections or medial branch blocks to help alleviate their back and neck pain. This type of pain affects approximately two-thirds of people in the United States over the course of their lifetimes, making this an extremely common condition that needs to be addressed. With such a high level of incidence, chronic spinal pain is the most common type of pain for people in the United States, and likely elsewhere. For back and neck pain, research has shown that up to 45% of all cases may be associated with the facet joints of the spine. Facet joint injections and medial branch blocks are, therefore, critical components of an effective strategy for pain management.

Facet joint injections or medial branch blocks can be used for more than just pain relief. They can also be effective diagnostic tools for identifying what is causing the neck and back pain that patients may be experiencing. When the application of local anesthetic and long-lasting steroids results in diminished pain emanating from the facet joints, it confirms the facet joint as the source of the pain, allowing for additional targeted therapies and additional long-term pain management, if necessary.

In some cases, the pain relief provided by facet joint injections and medial branch blocks is not enough to provide long-term relief. In these cases, additional therapies, such as exercise, physical therapy, acupuncture, or chiropractic care, may be required for effective pain-management. For most patients, the use of facet joint injections, medial branch blocks, or additional therapies offers non-invasive pain management of the neck and back without the need for surgery.

Acute injury or long-term stress may cause deterioration of the facet joints, ultimately leading to facet joint pain. Arthritis may lead to irritation and degradation of the facet joints, either as a result of age-related degeneration or an autoimmune disorder. In facet joint arthritis, the cartilage and synovial fluid in the joints begins to break down. These joint components are necessary for reducing friction and impact in the joint. Over time, this breakdown leads to irritation and pain in the spine. Poor posture or an abnormal curvature of the spine may also contribute to facet joint pain in the back or neck.

Anatomy Of The Facet Joints

Knowledge of facet joints is helpful in understanding how they function and how facet joint injections and medial branch blocks work. Facet joints, also known as zygapophysial joints, are the joints between the vertebrae. Facet joints are found on each side of the vertebrae in the neck and along a bony ridge of the spine in the lower back. Thin layers of cartilage separate and protect the small bony structures that make up the facet joints.

Facet joints are also protected by a layer of synovial fluid. This fluid is encased in a capsule that surrounds the joint. Synovial fluid is not limited to facet joints, and it provides a gentle fluid that reduces friction in mobile joints. This is important in the facet joints because they are responsible for allowing the torso and neck to bend and twist while providing stability to the spinal region. Decreased mobility and increasing levels of pain are associated with degeneration of facet joints.

What Is A Facet Joint Injection?

Facet joint injections are a type of nerve block used to treat pain originating from the spinal area such as the neck (cervical region), middle back (thoracic region), or lower back (lumbar region). Facet joint injections have been in use for over 50 years as a common nonsurgical treatment for lower back pain. In a facet joint injection, the facet joint area is injected with a local anesthetic (such as mepivacaine, lidocaine, or bupivacaine) along with a powerful steroid (such as cortisone or methylprednisolone). This combined treatment takes advantage of the immediate pain relief from anesthetics along with the long-lasting anti-inflammatory effects of the steroidal injection, providing rapid and prolonged relief to back pain.

Facet joint injections may be performed to assist in the diagnosis of back pain without the need for invasive surgical treatments. A successful treatment of pain is a clear indication that the facet joint was responsible for the pain, opening up opportunities for further directed treatments. Research supports the diagnostic role of facet joint injections with regard to back pain. Studies have shown that facet joint injections can be used successfully to both identify and treat chronic back and neck pain. In some cases, further therapies are not required and the facet joint injection alone is a sufficient treatment.

This is further supported by a recent study on patients receiving facet joint injections to treat back pain. Fifty patients, ranging from 20 to 70 years old, were treated with facet joint injections of a local anesthetic (bupivacaine) and a steroid injection (methylprednisolone) to treat their back pain symptoms. After three months, 74% of patients reported immediate pain relief and 19% of patients had complete pain relief.  This research supports facet joint injections as a noninvasive treatment for neck and back pain without the need for invasive surgical therapies.

How Are Facet Joint Injections Performed?

Patients are prepared for facet joint injections by first laying facedown on an X-ray table. Sedation, when necessary, is delivered by intravenous injection and vital signs are carefully monitored during the procedure. The injection site is thoroughly cleaned prior to injection. The area is numbed with a local anesthetic by the physician, who also makes use of a fluoroscopic dye to allow the physician to track the needle by X-ray. The use of X-ray or ultrasound imaging helps ensure accurate needle positioning at the injection site. Finally, the anesthetic and steroid medications are injected into the facet joint. The procedure is typically completed within 15 minutes, although a patient may be monitored for side effects prior to being discharged.

Facet joint injections are used to both identify and treat the source of neck and back pain. Patients experiencing relief following facet joint injections have the added benefit of avoiding a more invasive surgical procedure as an alternative. Their use as a diagnostic tool and an effective treatment has been supported by several clinical studies yielding positive outcomes for patients undergoing this procedure. In one study following patients for four weeks after facet joint injections, it was found that this procedure resulted in a 42-92% reduction in pain.

Although the risks are low with such a minimally invasive procedure, all medical procedures have side effects and facet joint injections are no exception. Rare complications include soreness, bleeding, or infection at the injection site, allergic reac