What are Facet Joint Injections?
Facet Joint Injections Performed by Las Vegas, Summerlin, and Henderson Nevada’s Top Pain Doctors
Patients referred for facet joint injections and medial branch blocks often show signs of facet degeneration caused by lumbar facet syndrome, neck pain, and other painful conditions. According to current research, approximately two-thirds of people in the United States suffer from back or neck pain at some time in their life span. In fact, chronic spine pain is the most common source of pain in the U.S. Facet injections and medial branch blocks are intended to alleviate this pain. In this capacity, they play a key role in a conservative pain management program for lower back and neck pain.
Along with their pain-relieving properties, facet joint injections and medial branch blocks have the added benefit of helping physicians identify the potential source of a patient’s pain. Through image-guided placement of the needle, powerful steroid medication and/or local anesthetic help to reduce inflammation in the facet joint area; therefore, confirming the facet joint as the cause of pain.
Once a diagnostic facet or medial branch block reveals the source of chronic lower back or neck pain, doctors and patients can make informed choices regarding an ongoing pain management program. Successful facet and medial branch blocks can improve function and quality of life for the patient without the need for invasive back surgery.
Injury or trauma could be a cause of pain in the facet joints. Arthritis, in which the joints or the protective synovial fluid around them wears down, can also occur in facet joints causing irritation. This can occur either with age or as the result of an autoimmune condition. Facet joint arthritis is also a source of pain and irritation in the spine. It is also possible that poor posture or abnormal spinal curvature may contribute to this type of back pain.
Facet Joint Anatomy
The anatomy of the facet joints can help explain how facet joint injections and medial branch blocks work. The facet joints, also known as zygapophysial joints, are located on the back of the spinal column in the lower back. In the neck area, they are located on both sides of the vertebra. There are two facet joints between each vertebrae located on both sides of the spine. The facet joints are small bony knobs that are separated by a thin layer of cartilage.
The joints are surrounded by a capsule that is filled with lubricating fluid. This fluid, known as synovial fluid, helps to reduce friction between the bones during movement. The facet joints also provide stability to the trunk, which allows you to bend and twist. Chronic pain often results because of degenerative changes in the synovial facet joint area. This can ultimately result in limited mobility and increased pain.
What is a Facet Joint Injection?
Facet joint injections are nerve root blocks used to treat back (lumbar) and neck (cervical) pain. The procedure was first reported over 50 years ago as a conservative approach for treating back pain. Facet injections are a common form of nonsurgical treatment for pain in the lower back, which originates in the facet joints. Research has indicated that the facet joint area may account for up to 45% of back and neck pain reported by patients. During a facet joint injection, the physician injects a combination of long-lasting steroids such as dexamethasome and a local anesthetic such as lidocaine, bupivacaine, or mepivacaine into the facet joint area. The steroid medication and/or anesthetic reduces inflammation in that area, which helps to alleviate pain.
Lumbar and cervical facet blocks are also routinely used as diagnostic tools to help determine the cause of pain. If the pain disappears, it is likely that inflammation in the facet joint was the source. Studies concerning the outcome of facet joint injections for back pain have yielded favorable results for identifying and relieving the source of chronic pain.
One recently reported study sampled 50 patients between 20 to 70 years of age, who were suffering from back pain. These patients were given a facet injection of the local anesthetic bupivacaine and the steroid methylprednisolone. The researchers conducted three month follow-up examinations on the patients, which showed that 74% of the patients felt immediate relief and 19% of those patients had complete pain relief at the conclusion of the study. From the results, the researchers concluded that facet joint injections are a reasonable pain-relieving option to invasive back or neck surgery.
What is a Medial Branch Block?
Medial branch blocks are an effective and direct way of treating pain originating from the facet joint of the spine. They deliver long-lasting steroids such as dexamethasome. In some cases a local anesthetic such as lidocaine, bupivacaine, or mepivacaine will also be injected. The medial branch block involves targeting the nerves that provide sensory signals to the facet joint (i.e. the medial branch) itself. Each facet joint is connected to two medial nerves that control small muscles in the back and neck. In the cervical area, the medial branch nerves are located on a bony groove in the neck. They are also found in a bony groove in the lower back area (lumbrosacral medial branch nerves). The thoracic medial branch nerves are located over a bone in upper back area.
During medial branch blocks, a needle is placed directly into the nerve, and delivers the compounds to relieve the facet joint pain more directly. Medial branch blocks have been found to be an appropriate and safe option for back and neck pain. The procedure has the advantage of being non-invasive and an alternative to surgery.
A lumbar medial branch block is a frequently performed procedure for diagnosing and treating low back, hip, buttock, and groin pain. Research has shown that inflammation and degenerative changes in the facet joints are responsible for about 10% to 15% of the cases with chronic lumbar pain. Lumbar medial branch blocks help to reduce this inflammation in the affected nerves of the facet joints. A cervical branch block can reduce pain in the upper back and neck, and headaches associated with facet damage in the cervical area.
Similar to facet joint injections, medial branch blocks also have diagnostic capabilities. If the patient’s pain disappears after the injection, then it most likely originated from the facet joint. Depending on the results of the injection, doctors may choose to prescribe physical therapy, future injections, or a radiofrequency facet ablation (RFA). This procedure annihilates the medial nerves, which blocks pain signals and can result in prolonged pain relief
How Are Facet Joint Injections Performed?
Prior to the procedure, the patient is positioned face-down on an x-ray table and the skin is sterilized and prepared for the injection. If sedation is needed, it will be delivered through an IV and vital signs (blood pressure, heart rate, and breathing) will be monitored throughout the procedure. The physician will then use an anesthetic to numb the area and a fluoroscopic x-ray is used to guide the needle to the correct place. During the fluoroscope x-ray, dye is injected. The dye shows up on the x-ray image, so the doctor can watch where it goes. The doctor then injects the anesthetic and cortisone into the same area. The entire procedure takes about 15 minutes.
The goal of the facet joint injection is to locate and reduce the source of pain. Positive clinical outcomes have helped corroborate that facet joint injections are accurate in locating the source of pain, and at the same time can provide a significant therapeutic benefit. For example, during a controlled study of patients with lumbar pain, facet joint injections were responsible for 42% to 92% pain relief within the four weeks following the injections. Other studies have shown that successful facet joint injections also had the added benefit of preventing premature surgical interventions.
Facet joint injections are minimally invasive; however, as with all procedures, there is still some potential risk of complications. Although rare, potential complications include bleeding, infection, headaches, nerve damage, and allergic reaction. The patient may also be sore at the site of the injection for about a week following the procedure.
Although rare, other potential issues associated with the procedure are related to technical errors, particularly the misplacement of the needle. This can be avoided by the use of techniques such as fluoroscopy or ultrasound to guide the needle to the precise location to be injected. Other side effects are associated with the steroidal medications. These risks include weight gain, facial flushing, elevated blood sugar, and insomnia. The local anesthetics used may cause desensitization of the nerve over time and potential interactions with other medications.
How Are Medial Branch Blocks Performed?
The patient is placed on the x-ray table and the skin is sterilized and prepped for the injection. If IV sedation is used, vital signs (blood pressure, heart rate, and breathing) will be monitored throughout the procedure. Once the skin is sterile, a local anesthetic is used to numb the area prior to the injection.
Next, the physician injects dye and uses a special real-time x-ray, known as a fluoroscope, to guide the needle to the correct location. This will help deliver the steroid medication as closely as possible to the inflamed nerve root. The physician will then inject a combination of anesthetic and a long-lasting steroid medication into the facet area.
At the conclusion of the procedure, a band-aide is placed on the site of the injection. The procedure takes approximately fifteen minutes. The patient is monitored for approximately 30 minutes and provided discharge instructions when it is time to leave. Patients typically feel pain relief benefits within a couple of days after the injection.
The main risks associated with this procedure are related to technical errors and issues, particularly the misplacement of the needle. A small number (approximately 3%) of medial branch blocks in the neck or upper back result in inadvertent injection into a blood vessel instead of the nerve. This can be avoided by the use of techniques such as fluoroscopy or ultrasound to guide the needle to the precise location to be injected. The accuracy of this combination is approximately 90%. Other potential risks of medial branch blocks include infection, bleeding, and nerve damage.
Some of the potential side effects related to the injection of steroid medication include elevated blood sugar, weight gain, and, ironically, arthritis. They can also cause stomach ulceration and reduction of the immune response. The local anesthetics used may cause desensitization of the nerve over time and interactions with other medications taken by the patient. In isolated cases (no more than 2% of patients receiving medial branch blocks) temporary neurological complications associated with local anesthetics, such as chest discomfort and nausea, occur. Consultation with a physician, who will assess the likelihood of complications, is advised before undergoing a medial branch block.
Preparation for the Procedures
To prepare for the procedure, physicians instruct patients to discontinue certain medications including non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen. This reduces the risk of bleeding during and after the procedure. Patients will also be instructed not to eat or drink anything for a specific time period prior to the procedure. Transportation must also be provided to and from the procedure. After the procedure, patients will be instructed to schedule a follow-up appointment to see if the injection or block was successful.
Conditions Related to Facet Joint Injections and Medial Branch Blocks
The exact source of back or neck pain is often difficult to diagnose in many people. Imaging studies, such as x-rays and MRIs, could show abnormalities in the spine that may be the cause of the pain. However, during clinical evaluation, doctors may need to conduct further examinations to help confirm the source of pain.
Doctors rely on facet joint injections and medial branch blocks to help them answer this question. Patients with lumbar facet pain usually experience pain in the lower back, buttocks, or hip. Patients with neck facet pain may have spasms in the neck muscles that cause pain as well as headaches. As with lumbar facet syndrome, the pain becomes worse during movement.
In both lumbar and cervical facet-associated pain, injections of steroids and local anesthetics can provide therapeutic relief. The diagnostic effect of the injection comes into play if the steroid medication reduces or eliminates the pain. Once your pain specialist identifies the facet joint as the cause, additional therapeutic facet joint injections may be performed at a later date.
There are a variety of conditions that doctors rely on facet joint injections and medial branch blocks to treat. To assist with an effective pain management program, pain specialists will investigate other potential causes of pain, such as herniated discs, degenerative disc disease, spinal stenosis, and spondylolysis. In most cases, facet joint injections and medial branch blocks are used to treat facet-related pain, known as facet syndrome.
Patients referred for medial branch blocks often show signs of facet degeneration caused by facet syndrome. The basic anatomy of the facet joints can help explain how this pain originates. The facet joints provide stability to the back during movement. The facet joints are about the size of a thumbnail, and they connect the vertebrae at the side of the spine. The facet joints are separated by a thin layer of cartilage and are surrounded by a capsule filled with synovial lubricating fluid. Medial branch nerves are located near the facet joints and are responsible for sending pain signals from that area to the brain.
The facet joints are constantly in motion. As a person ages, the cartilage gradually wears away. When this happens, painful bone spurs can develop at the edge of the facet joint, which cause additional aggravation to the facet area. Friction between the bones in this region leads to pain, inflammation, tenderness, and stiffness. The bone spurs may form in the opening where the nerve root exits the spinal canal. This area, known as the neural foramen, becomes inflamed when the bone spurs rub against the nerve root.
Although facet syndrome is generally a result of the natural aging process, it can also be caused by injury or overuse in youth. Along with age and overuse, there are other risk factors that may contribute toward facet syndrome. These factors include family history, excessive weight, and traumatic injuries, such as whiplash. During the diagnostic stage of back and neck pain, physicians examining an MRI or CT scan often notice signs of moderate spinal arthritis in the spine.
Patients with lumbar facet syndrome often feel pain in the lower back area that radiates to the buttocks and hip area. If facet related aggravation occurs in the cervical region, pain often manifests in the upper back, neck, and in the back or the head. The pain can radiate to the top of a person’s head, shoulders, and upper arms.
This pain is typically exasperated during movement, such as extension of the spine. Successful facet blocks relieve this pain and therefore confirm the facet joint as the source of the pain. Facet joint disease or damage is implicated in neck, upper back, and lower back pain, originating from joints in cervical, thoracic, and lumbar vertebrae respectively. They can be injected separately to treat the pain in each relevant condition.
The pain associated with facet syndrome may feel like a dull ache that constantly returns after activity. As the disease progresses, the pain tends to last longer. At first, one joint may be affected; however, over time several joints may be involved, which exasperates the pain. Other symptoms include:
- Lower back pain that radiates into the thighs, pelvic areas, or buttocks
- Neck pain that radiates into the shoulders, arms, or head
- Pain that is worse in the morning or evening
- Pain that is set off with a change in weather
- Pain that worsens during walking, standing, and sitting for long periods of time
- Abnormal curvature of the spine
- Weakness in arms or legs
- Slowed reflexes
People who suffer from facet syndrome also typically have other comorbid conditions that cause pain. These conditions often include spinal osteoarthritis, degenerative disc disease, herniated discs, spinal stenosis, as well as other potentially disabling conditions. Examining these coexisting conditions will help patients understand the similar symptoms, which they often present with facet joint pain.
Spinal osteoarthritis affects the lower back by breaking down the cartilage located between facet joints. This cartilage, composed of slick, elastic tissue, serves as a protective buffer between the bone, which attempts to minimize the impact of jumping, bouncing, and everyday activities. As the facet joints become inflamed, progressive degeneration of the joints occur, causing increased pain.
While a specific cause of spinal osteoarthritis is unknown, there are several factors that contribute to the increased risk of suffering from this condition. These factors include age, gender, weight, genetics, and associated diseases. A person in their mid-30s with a history of athletics or repetitive work involving moving heavy objects is at greater risk of suffering from spinal osteoarthritis.
Patients that suffer from spinal osteoarthritis report severe pain in the lower back and neck region. Pain increases over time, as the cartilage degenerates. Patients also have limited mobility and decreased flexibility of the back. Bone spurs often occur around the degenerating facet joint and can pinch the spinal nerves causing pain. Joint tenderness is also common among patients with spinal osteoarthritis as well as a rubbing sensation when flexing the back.
Several stretching exercises have been shown to decrease the painful symptoms of spinal osteoarthritis. Abdominal strengthening exercises, which increase support of the spine, have been shown to decrease symptoms. Facet joint injections and medial branch blocks can also be helpful with any pain in the facet area caused by spinal arthritis.
Degenerative Disc Disease
The degeneration of the intervertebral disc is the cause of many painful problems in the spine. Throughout the day, the spine is constantly in motion and forced to support the body’s weight. However, with age, the discs eventually begin to degenerate from daily wear and tear. When a patient suffers from degenerative disc disease, the main source of pain is caused by the intervertebral disc. These discs are located between each vertebra of the spine and designed to absorb shock during normal daily routines. Without these discs, or shock absorbers, the bones they protect would be damaged. Degenerative disc disease occurs when these discs lose their ability to act as a cushion. This is due to the loss in water in the disc nucleus and the narrowing of space between the two vertebrae. Water loss happens when the discs are damaged and tear. The facet joints are forced to shift to realign themselves with the changing disc size.
The most common symptom of degenerative disc disease is severe pain in the back that spreads to the buttocks and upper thigh. A degenerative disc is usually the initial cause of back pain but eventually affects all parts of the spine. As the disc degenerates, several problems arise from the disc itself. A damaged intervertebral disc is commonly referred to by specialists as discogenic pain. This deterioration of the disc results in fissures, and disc bulges, which can often result in chronic pain. Discogenic pain is often felt in the lower back; however, it can also be present in other parts of the back and neck. It is common for a bulging disc to push on a nerve, which creates radiating pain in other areas of the body. Problematic discs in the lumbar region often produce pain in the leg, known as sciatica. Pain, numbness, and/or tingling may also be present in the feet. Conversely, weakened discs in the cervical area may produce pain, tingling, and/or numbness in the arms and hands.
In order for a physician to diagnose the level of degenerative disc disease, a complete medical history assessment and physical examination are necessary. During a physical examination, the physician tests the motion of the spine and neck, along with potential weakness, tenderness, and pain. The doctor also tests reflexes and motor skills. X-rays and magnetic resonance imaging (MRI) may be required to determine the amount of damage to the disc.
Once diagnosed, medical professionals will prescribe a treatment plan, ranging from conservative treatment to surgery. Conservative treatment plans include rest and over-the-counter medications, including aspirin. Narcotic pain medications can be prescribed for severe back pain. Pain specialists also treat degenerative disc disease with other conservative options, such as epidural steroid injections. These injections are a combination of cortisone and a local anesthetic given directly into the back. Physical therapy and exercise are common treatment recommendations for degenerative disc disease. Physical therapy includes the use of massage, ultrasound, and electric stimulation.
Must Watch Video – Disc Tear Explanation
A herniated disc occurs when all or part of a disc ruptures through a weakened part of the same disc. The rupturing places pressure on nearby nerves or the spinal cord, causing severe pain, numbness of the lower extremities, or general weakness. There are several symptoms of a herniated disc in the lower back, including a sharp pain in the legs, buttocks, or hips. The pain is not always immediate and can start slowly and then increase while standing or sitting for a long period. Pain can also be present while lying down, sneezing, or during general daily activity.
A medical examination is necessary to diagnose a herniated disc. During the examination, the physician will check for numbness, test reflexes, strength, and posture. The physician will also test for mobility, flexibility, and perform diagnostic tests. An electromyography test can be conducted to check the health of muscles and nerves controlling those muscles. A myelogram can be used to determine the size and location of the disc herniation. An MRI and CT scan may be used to scan the lower spine and surrounding tissue.
Treatment for a herniated disc includes rest, physical therapy, and medication for the pain. Lifestyle changes are usually necessary, which includes an increase in aerobic exercise, stretching, and avoiding heavy lifting. Physical therapists teach patients how to lift weights, walk, sit, stand, and perform other daily activities. Physicians also rely on non-surgical options, such as epidural steroid injections, medial branch blocks, radiofrequency ablation, and other nerve blocks to help manage the pain.
Over 95% of people have degenerative changes of the spine by age 50. This disorder, also known as spinal stenosis, often occurs in adults over the age of 60. As we age, the bones on our spine harden and become overgrown. This change can lead to a narrowing of the spinal canal. This narrowing puts pressure on the spinal cord and can cause pain, numbness, or weakness.
The most common cause of spinal stenosis is arthritis. Disc degeneration occurs when the water content in a disc is lost and the space in the spinal canal narrows. Arthritis can form in the disc once the space narrows. As we get older, the water content in each disc naturally decreases.
Spinal stenosis can be diagnosed in a variety of ways. A doctor may use a patient’s medical history and recent activity to diagnose spinal stenosis. Questions regarding previous spinal injuries and general health problems are used to assist medical personnel in an accurate diagnosis. A physical examination, including mobility, flexibility, and muscle strength, are also used to diagnose spinal stenosis. Physicians also rely on x-rays, MRI studies, and CAT scans to identify spinal stenosis through two-dimensional pictures, cross-sectional images, and three-dimensional views. A myelogram can also help physicians detect spinal stenosis through the injection of dye that shows abnormalities in the spinal canal.
There are several non-surgical treatments of spinal stenosis including non steroid anti-inflammatory drugs (NSAIDs), pain medication, anesthetic injections, and prescribed exercises that help strengthen the abdomen and back muscles. Alternative therapies for spinal stenosis include acupuncture and chiropractic treatments. Surgery for spinal stenosis is necessary to relieve pressure on the spinal cord but should only be considered after non-surgical treatment has been exhausted.
Chronic pain caused by facet degeneration can be discouraging; however, a wide variety of studies have shown that facet joint injections and medial branch blocks remain viable alternatives to back surgery to help relieve pain. These non-invasive procedures are often combined with physical therapy and non-steroidal anti-inflammatory medication (NSAIDs). This helps reduce inflammation and assists the patient with daily functioning, which will help increase the quality of life. The following recent studies shine some light on the scientific research that bolsters the use of these two procedures.
Current medical literature has supported the efficacy of lumbar medial branch blocks to manage facet joint-related pain. These studies have reported that this combination of powerful steroids and local anesthetic can have immediate and long-lasting pain relieving affects on low back pain. Several randomized controlled trials have also documented the importance of lumbar medial branch blocks for diagnosing pain originating in the facet joints. In fact, current medical guidelines suggest the use of medial branch blocks in addition to imaging studies to help diagnose lumbar facet pain. Research has supported the role of facet joint injections as both a therapeutic and diagnostic tool to manage lower back pain.
One recently reported study evaluated the outcome of facet joint injections in patients with low back pain. During this investigation, patients were monitored for a period of nine months after receiving facet joint injections for lumbar pain. The results of the investigation revealed that the facet injections were successful in alleviating pain in 74% of the test participants.
Studies have also focused on the accuracy of diagnostic lumbar medial branch blocks. One study reported in a 2009 edition of Pain Physician, conducted a two-year follow-up of patients that received diagnostic lumbar medial branch blocks to investigate for potential facet joint degeneration. The outcome of this study revealed that the diagnostic blocks were successful in identifying the facet joints as the source of pain in 93% of the test subjects after a one-year observational period and 89.5% after a two-year follow-up study. Another study helped to corroborate this information. During this randomized, double-blind, controlled trial, patients were treated with a medial branch block of bupivacaine and a steroidal medication; they were then assessed after one year. During this year-long study, physicians administered three to four injections to the patients. The results of this study revealed that 83% of the patients with neck pain and 79% of patients with upper back pain showed significant functional improvement and pain relief at the conclusion of the study.
Cervical medial branch blocks have a low incidence of side-effects, and provide moderate short-term relief from neck pain. Thoracic medial branch blocks can control upper- and mid-back pain. They have been reported to restore at least 50% normal functions in over 80% of patients, over a period of two years. Lumbar medial branch blocks control lower back pain, and can restore at least 40% normal function with a decrease of approximately 50% in pain experienced. Cervical, lumbar, and thoracic medial branch blocks are also useful in diagnosing the cause of spinal problems, i.e. in evaluating the possibility of facet joint arthritis or damage as the source of pain.
The American Society of Regional Anesthesia and Pain Medicine published a recent study that examined the clinical outcomes of cervical medial branch blocks in diagnosing facet syndrome. During this study, patients with facet-related neck pain were given cervical medial branch blocks using ultrasound guidance. The results indicated that cervical medial branch blocks had positive therapeutic as well as diagnostic outcomes in approximately 94% of the cases.
Facet joint injections and medial branch blocks are effective in controlling the pain associated with facet joint arthritis and back pain. The anesthetic injected relieves pain while the steroid acts to reduce the inflammation and irritation associated with arthritis or joint damage. Research has shown that the treatment is used in controlling pain originating from facet joints in the vertebrae of the neck, upper and lower back. It is also employed in diagnosing the cause of pain in these areas. Facet joint injections and medial branch blocks provide pain relief in the short to medium term, and restore a significant degree of function and normal daily activities to patients receiving this treatment. They remain a conservative option to help pain specialists find the precise location of pain in the spine and eliminate it without the use of invasive back or neck surgery.
- Boswell MV, Colson JD, Sehgal N, et al. A systematic review of therapeutic facet joint interventions in chronic spinal pain. Pain Physician. 2007;10(1):229-253.
- Cohen S, Strassels S, Kurihara C, et al. Randomized study assessing the accuracy of cervical facet joint nerve (medial branch) blocks using different injectate volumes. Anesthesiology. 2010;112:144-152.
- Cohen S, Eaja S. Pathogenesis, diagnosis, and treatment of lumbar zygapophysial(facet) joint pain. Anethesiology. 2007;106:591-614.
- Cohen S, Williams K, Hurihara C, et al. Diagnostic medial branch blocks before lumbar radiofrequency zygapophysial (facet) joint denervation. Anesthesiology. 2010;113:276-278.
- Falco FJ, Manchikanti L, Datta S, et al. Systematic review of the therapeutic effectiveness of cervical facet joint interventions: an update. Pain physician. 2012;15(6):E839-868.
- Finlayson R, Gupta G, Alhujari M, et al. Cervical medial branch block. Reg Anesth Pain Med. 2012;37(2):219-233.
- Jentzsch T, Geiger J, Konig MA, Werner CM. Hyperlordosis Is Associated With Facet Joint Pathology At The Lower Lumbar Spine. Journal of Spinal Disorders & Techniques. Sep 27 2013 [Epub ahead of print]
- Kim D, Choi D, Kim C, et al. Transverse process and needles of medial branch block to facet joint as landmarks for ultrasound-guided selective nerve root block. Clinics in orthopedic surgery. 2013;5(1):44-48.
- Manchikanti L, Singh V, Falco FJ, et al. The role of thoracic medial branch blocks in managing chronic mid and upper back pain: a randomized, double-blind, active-control trial with a 2-year followup. Anesthesiology research and practice. 2012;2012:585806.
- Lee C, Kim Y, Shin J, et al. Intravascular injection in lumbar medial branch block: A prospective evaluation of 1433 injections. Anesthesia & Analgesia. 2008;106(4):1274-1278.
- Massaia S, Nano G, Mammucari M, et al. Medial branch neurotomy in low back pain. Neuoradiology. 2012;54:737-744.
- Pedicelli A, Verdolotti T, Pompucci A, et al. Interventional spinal procedures guided and controlled by 3D rotational angiographic unit. Skeletal Radiol. 2011;40(12):1595-15601
- Riew KD, Park JB, Cho YS, et al. Nerve root blocks in the treatment of lumbar radicular pain. A minimum five-year follow-up. The Journal of Bone and Joint Surgery. American volume. 2006;88(8):1722-1725.
- Schutz U, Cakir B, Dreinhofer K, et al. Diagnostic value of lumbar facet joint injection: a prospective triple cross-over study. Plos One. 2011;6(11):e27991.
- Verrills P, Mitchell B, Vivian D, Nowesenitz G, Lovell B, Sinclair C. The incidence of intravascular penetration in medial branch blocks: cervical, thoracic, and lumbar spines. Spine. 2008;33(6):E174-177.