What Are Facet Joint Injections And Medial Branch Blocks?
Table of Contents
- 1 What Are Facet Joint Injections And Medial Branch Blocks?
- 2 Anatomy Of The Facet Joints
- 3 What Is A Facet Joint Injection?
- 4 How Are Facet Joint Injections Performed?
- 5 What Is A Medial Branch Block?
- 6 How Are Medial Branch Blocks Performed?
- 7 Preparation For Facet Joint Injections And Medial Branch Block Procedures
- 8 Conditions Related To Facet Joint Injections And Medial Branch Blocks
- 9 Recent Studies
- 10 Conclusion
- 11 References
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 JointsKnowledge 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 reactions, headaches, and nerve damage. In particular, soreness resulting from facet joint injections may last up to a week and is not uncommon.
Other rare complications arise from technical errors in the facet joint injection procedure. One such risk is a misplaced needle, which is addressed by ultrasound or the use of a fluoroscopic dye to view the needle and help ensure proper placement prior to injection. The steroidal medication used may also cause side effects. Steroidal medications can cause facial flushing, elevated blood sugar, insomnia, or weight gain. The local anesthetics used in this procedure may have complications with other medications the patient may be taking or they could cause desensitization of the local nerves.
What Is A Medial Branch Block?Another effective treatment for back or neck pain originating in the facet joint regions are medial branch blocks. Unlike facet joint injections that target the joint itself, medial branch blocks target the medial branch nerves associated with the facet joint. Each vertebra contains two medial nerves connected to the facet joints. These nerves control the small muscles in the neck and back. Depending on the region of the spine, the specific location of the medial branch nerves vary slightly with relation to the vertebrae. Cervical and lumbar medial branch nerves are located on bony grooves of the neck and lower back, respectively, while thoracic medial branch nerves are located over a bone in the upper back.
To perform a medial branch block, a needle is first placed alongside the target nerve so that the drugs can be delivered directly to where they will be most effective. Next, a physician injects a local anesthetic, such as lidocaine, bupivacaine, or mepivacaine next to the target nerve. Along with the anesthetic, a powerful, long-lasting, anti-inflammatory steroid, such as dexamethasone, is injected. As with facet joint injections, this is a non-invasive procedure that offers a less intensive alternative to surgical procedures while maintaining a high degree of effectiveness and safety.
Ten to 15% of chronic lumbar pain cases are attributable to degenerative diseases and inflammation that can cause pain in the hips, back, buttocks, and groin. Lumbar pain may be partially diagnosed with the help of a lumbar medial branch block. Through direct targeting of the affected nerves, lumbar medial branch blocks are effective at relieving pain originating in the nerves of the facet joints. Cervical medial branch blocks are useful for treating pain in the head and neck by reducing pain associated with damage to the cervical facet joints.
As with facet joint injections, medial branch blocks are useful diagnostic tools when working with back and neck pain. A successful medial branch block and associated pain relief is an indicator that the irritated, inflamed, or injured nerve or joint has been correctly identified. For sources of chronic pain identified in this way, other options exist, including additional injections, physical therapy, or radiofrequency ablation (RFA). RFA is the most disruptive of these therapies. RFA is effective at providing long lasting benefits of pain reduction by destroying the problematic medial nerves and blocking any pain signals that they may have mediated.
How Are Medial Branch Blocks Performed?Although medial branch blocks target the nerve instead of the facet joint, the procedure is very similar to a facet joint injection. Patients undergoing medial branch blocks begin by lying facedown on an X-ray table. Sedation, if used, is delivered by intravenous injection by the physician and vital signs, including blood pressure, heart rate, and breathing, are carefully monitored throughout the procedure. The injection site is sterilized prior to injection. The area is numbed with a local anesthetic and a fluoroscopic dye is injected 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 directly to the nerve root. The procedure is typically completed within 15 minutes, although a patient may be monitored for side effects prior to being discharged. Patients typically experience pain relief within a few days of the procedure.
Some risks of complications from a medial branch block are due to technical errors based on the placement of the needle. About 3% of the time, the injection occurs in a nearby blood vessel, missing the nerve itself. Fortunately, needle placement is often aided by ultrasound imaging or the use of fluoroscopic dyes with X-ray imaging to reduce this risk. Soreness, redness, bleeding, or infection at the injection site are also risks associated with medial branch blocks. Another risk factor to be aware of is possible nerve damage.
The medications used for medial branch blocks also come with possible side effects. The use of steroids can lead to facial flushing, elevated blood sugar, or suppression of the immune system. Over time, the use of local anesthetics can lead to complications with other medications or localized nerve desensitization. Less than 2% of medial branch block patients also experience temporary neurological side effects. Possible neurological complications resulting from the local anesthetic include chest discomfort and nausea. Prior consultation with your physician will allow for early identification of risk factors that may be specific to your treatment so that proper steps can be taken to minimize your risks.
Preparation For Facet Joint Injections And Medial Branch Block ProceduresThe use of non-steroidal anti-inflammatory drugs (NSAIDs) can increase the risk of side effects due to interactions with the anesthetics. The use of NSAIDs can also increase the risk of bleeding during the procedure. Therefore, patients are asked to discontinue use of NSAIDs prior to these treatments. Patients are also recommended to abstain from fluids and food for a certain amount of time before their appointments.
Following the anesthetic or sedation, patients will not be allowed to drive, so other forms of transportation must be arranged. The long-term effectiveness of these procedures will be assessed by the physician during follow-up appointments.
Conditions Related To Facet Joint Injections And Medial Branch BlocksDespite how common back and neck pain are, identifying the exact cause or source of the pain is often a very difficult process. When there is a physical deformation in the neck or spine, it may be identified by imaging techniques, such as MRI. For most patients, a physician will conduct a detailed physical examination before determining what is causing the pain for that patient.
Facet joint injections and medial branch blocks may be used as diagnostic tools to help identify the source of neck and back pain. Lumbar facet joint pain may cause pain in the hips, buttocks, or lower back. Cervical facet pain may lead to pain in the neck or head. In any case, pain of the joints is often made worse by movement.
Local anesthetics and steroid injections may relieve pain originating from the cervical or lumbar facet joints. Once pain is better controlled in these areas through facet joint injections or medial branch blocks, the facet joints can be identified as the source of the pain and targeted using additional treatments for long-term pain management.
Patients who have received diagnostic facet joint injections and medial branch blocks may be referred to a pain specialist to help identify the source of their pain and how to best manage it. Sources of facet joint pain include spinal osteoarthritis, degenerative disc disease, herniated discs, and spinal stenosis. If the pain is localized to the facet joints without symptoms elsewhere, it may also be caused by facet syndrome.
Facet syndrome leads to degeneration of the facet joints. Many patients receiving facet joint injections and medial branch blocks exhibit symptoms of facet syndrome. Facet joints, although only the size of a thumbnail, provide stability to the spine and back. Facet joints are located on the side of the spine and connect the vertebrae together while providing mobility to the spinal column. The facet joints are separated by thin layers of cartilage and are surrounded by small capsules of synovial fluid, allowing them to move and flex while reducing the damage caused by friction of the vertebrae against each other. The medial branch nerves are located near the facet joints and are responsible for transmitting pain signals from the facet joint areas to the brain.
The cartilage in the facet joints undergoes large amounts of wear as we get older. As the cartilage begins to wear away as a result of continuous movement throughout our lives, bone spurs may develop and lead to irritation and pain of the facet joint. The friction caused by damaged cartilage can also lead to inflammation, stiffness, soreness, and pain. Bone spurs can also cause pain and inflammation if they form in the neural foramen, which is where the nerve root exits the spinal cord.
Although age can be a major contributing factor, facet syndrome can also arise due to stress or injury of the facet joint. Individuals with family histories of facet syndrome or those who have suffered from a traumatic injury or are overweight are all at increased risk of facet syndrome. If a patient is suffering from spinal arthritis, then a diagnostic CT scan or MRI may help the physician diagnose a patient with facet syndrome.
Lumbar facet syndrome may be present in patients experiencing pain in the lower back that radiates down to the hips or buttocks. Cervical or thoracic facet syndrome can lead to headaches or pain in the neck and upper back. Cervical facet syndrome may also cause pain to radiate up toward the top of the head or outward to the upper arms.
Facet joint pain is often made worse by movement. Depending on the facet joints affected, the pain will be felt at different locations. Localized pain can be very helpful in rapidly identifying the source of the pain and which facet joints should be targeted for treatment. Pain originating in the neck, upper back, or lower back may be the result of injury or damage to the cervical, thoracic, or lumbar facet joints, respectively.
The pain caused by facet syndrome is likely to be present following movement or activity and be felt as a dull aching pain. The longer a patient has had facet syndrome, the more severe and long-lasting the pain will be. Untreated facet syndrome may also lead to additional affected joints, resulting in additional pain.
Additional symptoms may include:
- Slowed reflexes
- Abnormal curvature of the spine
- Pain that is affected by the weather
- Pain that is worst at specific times of the day
- Pain that follows prolonged sitting or standing
- Pain emanating from the lower back into the hips, buttocks, or thighs
- Pain emanating from the neck and moving out to the head or shoulders
The pain associated with facet syndrome is often accompanied by spinal osteoarthritis, degenerative disc disease, herniated discs, spinal stenosis, or other conditions. Understanding these conditions is essential to providing an effective diagnosis and treatment.
In spinal osteoarthritis, the cartilage between the facet joints in the lower back begins to break down. This results in a loss of the soft cushioning material that protects the vertebrae from impacts and irritation of everyday use. The inflammation that results from this irritation can lead to additional decay, which exacerbates the pain and irritation.
Spinal osteoarthritis has many causative factors, such as weight, disease, genetics, gender, and age. These risks are further increased based on the type of activity. The types of activity that can increase the risk of spinal osteoarthritis include heavy exercise, back injuries, or repetitive tasks.
As the cartilage in the joints of the neck and lower back continues to degrade, the pain in these regions will continue to increase. The inflammation and associated pain results in decreased flexibility and mobility of the patient. Additionally, bone spurs may form, increasing the pain and irritation to the area. The continual loss of protective cartilage between the vertebrae may lead to a rubbing sensation or tenderness of the spine when the patient moves.
The symptoms of spinal osteoarthritis can be partially managed by gentle stretching and exercise. Exercises that strengthen the back and abdominal muscles that support the torso are also beneficial. Lastly, facet joint injections and medial branch blocks may also be used to treat pain resulting from spinal osteoarthritis.
Degenerative Disc Disease
Degeneration of intervertebral discs leads to many painful conditions of the spine. The intervertebral discs help support the body’s weight and are under constant stress. These discs are the shock absorbers of the spine, absorbing the forces of impacts throughout our lives and protecting the vertebrae that they are situated in between. Over time, this constant load and pressure can cause degeneration of the intervertebral discs, leading to back and neck pain. The discs become more damaged over time, eventually tearing and leaking. As the discs nucleus loses fluid, the vertebrae squeeze closer together, causing the facet joints to shift. As the ability of these discs to cushion the spine is diminished, a patient may develop degenerative disc disease.
Any of the intervertebral discs can succumb to degenerative disc disease, although many patients first experience pain in the lower back. Degenerative disc disease may lead to other, more serious, conditions. As the discs deteriorate, they become misshapen and begin to bulge or crack. These malformations can lead to additional pain originating from the disc. This pain is also referred to as discogenic pain. Although the pain associated with degenerative disc disease most commonly begins in the lower back, it can spread to other areas of the upper back and neck.
Bulging discs can put excessive pressure on the nerve bundles that come out of the spine. This pressure causes severe pain that may be felt elsewhere in the body, such as the limbs. Sciatica pain is the result of damaged lumbar discs whose nerves extend downward to the legs. This explains why sciatica causes tingling, numbness, and pain throughout the legs and into the feet. Similar problems can occur depending on the discs that are affected. If discs in the cervical region are damaged, the pain and sensations may be experienced in the arms, shoulders, or hands.
A physician will request a patient’s complete medical history and perform a full medical examination prior to diagnosing degenerative disc disease. During this examination, they will test for nerve damage by evaluating motor skills and reflexes. They will also check for numbness, weakness, or tenderness in the neck and spine in addition to testing the range of motion through these regions. When necessary, potential disc damage may be visualized by X-ray imaging or MRI.
Depending on the extent of degenerative disc disease, treatment options vary. For patients in the early stages of this disease, treatments may be limited to oral anti-inflammatory medications (e.g., NSAIDs) and sufficient rest or reduced activity. For patients with more severe symptoms, the physician may prescribe narcotic medications for more aggressive pain relief. The physician may also prescribe physical therapy, electric stimulation, massage, ultrasound, or exercise as part of a patient’s pain management regimen. Patients may also receive epidural anesthetic and steroid injections.
A herniated disc occurs when part of the disc is weakened to the point of rupturing. The tissue within the disc pushes through the rupture, resulting in a herniated disc. This bulging tissue pushes on the nearby nerves or on the spinal cord, which results in symptoms ranging from numbness and weakness to extreme pain in the extremities. The associated pain may be delayed from the time of herniation and occur during normal activity. This pain may occur in the buttocks, hips, or legs following an extended period of standing or sitting.
A complete medical exam is required prior to the diagnosis of a herniated disc. A physician will examine a patient’s strength, reflexes, posture, numbness, and pain. They will also assess the range of motion and mobility of the patient. An electromyography may be used to test the condition of muscles and associated nerves. A myelogram may then be used to help identify the herniated disc. When necessary, CT scans or MRI may be used to visualize the discs and surrounding tissues to check for damage and to identify the herniated disc.
Although herniated discs can be treated, proper management also requires changes in lifestyle. Most treatments require rest, medication, and physical therapy. The physical therapist may recommend stretching, aerobic exercise, and changes to daily activities to prevent further damage to the affected discs. Physical therapy is useful in training patients on new habits to prevent further injury. When these treatments are insufficient, other non-surgical options exist, including medial branch blocks, nerve blocks, radiofrequency ablation to destroy the pain-sensing nerves, or epidural steroids.
Degenerative spinal diseases are extremely common, affecting approximately 95% of people by the age of 50. As we age, our vertebrae become overgrown and harden, which leads to spinal stenosis. In spinal stenosis, the spinal canal narrows, putting pressure directly on the spinal cord. This pressure causes pain, weakness, and sometimes numbness.
Most spinal stenosis is the result of arthritis, largely because the risk increases with age. The fluid content begins to decrease in our discs with age. As this happens and the discs narrow, our vertebrae shift. This shifting causes a narrowing of the spinal canal and additional wear on the cartilage, leading to arthritis.
Several evaluations can be performed to diagnose spinal stenosis. In some cases, a diagnosis may be as simple as a full review of the patient’s medical history and recent activities. Other health issues and any previous injuries to the spine are also helpful in assessing the patient. When a physical examination is performed, the physician will assess flexibility, mobility and strength. When necessary, the physician may also request X-rays, MRI, or CT scans to obtain detailed images of the spine. If specific visualization of the spinal canal is necessary, a dye may be injected into the spinal canal and visualized by electromyelography.
Surgical and non-surgical treatments exist for spinal stenosis. Non-surgical treatments include anesthetic injections, oral medications, and strength exercises for the core trunk musculature. Alternative therapies for spinal stenosis include chiropractic care and acupuncture. In the event that these options are insufficient treatments for pain relief, surgical options may be considered to diminish pressure on the spinal cord.
Recent StudiesSeveral studies have supported the use of facet joint injections and medial branch blocks for treating back pain. By combining these safe, non-surgical therapies with analgesic medications (e.g., NSAIDs) and physical therapy, their effectiveness can be extended even further. These treatments are able to identify the source of the pain and rapidly reduce the pain at the site of damage or injury. They also reduce swelling and inflammation, which is critical for long-term care and pain management. The studies included herein further support the treatment of back and neck pain with facet joint injections and medial branch blocks.
The use of lumbar medial branch blocks has been supported by recent clinical studies. These studies demonstrated that patients experienced immediate and long-lasting pain relief following injections with anesthetics and steroids. As indicated above, medial branch blocks can also be powerful diagnostic tools in determining the source of facet joint pain. Current medical recommendations support the evaluation of lumbar facet pain with medial branch blocks.
The use of facet joint injections to successfully treat lower back pain and as diagnostic tools is also supported by the current literature. In one such study, patients were followed for nine months after receiving facet joint injections for lumbar pain. At the conclusion of the study, alleviation of pain symptoms was reported in 74% of the patients having undergone lumbar facet injections.
Studies have also investigated the use and accuracy of lumbar medial branch blocks as diagnostic tools for facet joint pain. In the journal Pain Physician in 2009, a two-year study followed patients who had received diagnostic lumbar medial branch blocks to evaluate facet joint degradation. The investigators found that these blocks were overwhelmingly successful in correctly identifying the facet joints responsible for the patients’ pain with success rates of 93% after one year and 89.5% at the conclusion of the study.
Subsequent to these findings, a double-blind randomized trial was performed to evaluate medial branch blocks. In this trial, patients received a medial branch block in which the anesthetic, bupivacaine, was administered with or without the addition of a steroid. Three to four injections were performed over the course of one year, at which point the patients were evaluated again. This study also reported overwhelming success. 83% of patients experiencing neck pain reported significant improvements, while 79% of patients with upper back pain reported significant improvements.
Another study examined medial branch blocks in the diagnosis of back and neck pain. Lumbar medial branch blocks were found to provide a 50% reduction in pain along with the restoration of greater than 40% of normal function, while 80% of patients receiving thoracic medial branch blocks experienced a 50% restoration of normal function.
In 2012, a study was published in American Society of Regional Anesthesia and Pain Medicine that investigated the use of cervical medial branch blocks and their diagnostic use in patients with facet syndrome. In this study, ultrasonic needle guidance was used to perform cervical medial branch blocks on patients with facet-related neck pain. Positive therapeutic and diagnostic outcomes were reported in 94% of patients.
ConclusionFacet joint injections and medial branch blocks can be used to successfully treat facet joint pain, which is a major source of back and neck pain. These procedures provide rapid and lasting relief for patients via a non-surgical treatment with anesthetic and steroidal medications. Recent studies have demonstrated the safety and effectiveness of these treatments for facet joint pain in the neck, upper back, and lower back. Patients receiving facet joint injections and medial branch blocks experience increased mobility and decreased pain. These procedures provide effective pain relief through a non-invasive, surgery-free option for patients suffering from neck and back pain.
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