Located between neighboring vertebrae, the facet joints provide the spinal column with integrity. They do this by acting collectively to guide, and keep in check, common movements the spine makes such as:
In other words, facet joints will keep the spine from twisting too far, extending back too much, and other movements. Facet joints also help prevent a vertebra from slipping forward over the one below it.
The facet joints are located behind the bodies of the vertebrae and act as a sort of guide rail or railroad track when you move your trunk. Individual vertebrae are connected to one another by pairs of facet joints, two above and two below. Each facet joint is comprised of a downward bony projection called the inferior articular process, from the vertebra above, and an upward projecting one, called the superior articular process, from the vertebra below. The flat surfaces of these processes touch and glide against one another. With the help of numerous ligaments, this is how the individual 26 spinal bones connect together to make a column. The facet joints also provide stability to the spine.
The facet joints are shaped, sized and oriented differently according to the area of the spine they are located. These differences mean that certain areas of the spine are naturally more flexible than others.
Facet joints in the neck are adapted for movement in all directions. In the upper and mid back, called the thoracic spine, facets are angled for a good amount of rotation (turning and twisting), but the presence of your rib cage limits that movement. In the lumbar area, the facet joints face each other, which especially limits your ability to rotate (twist) your low back.
The facet joint is a synovial joint, which means it’s enclosed by a capsule made of connective tissue. The capsule is called the facet joint capsule.
Damage to facet joints is one common reason for chronic spine pain. A 2004 study in BMC Musculoskeletal Disorders evaluated 500 people with non-specific back pain and found that the facets were responsible for 55% of the cases. Two of the most common problems that cause facet joint pain include osteoarthritis and whiplash.
Osteoarthritis and Facet Joints
The bones of the facets are lined with cartilage, which cushions the joint. Osteoarthritis of the spine occurs when the cartilage wears out, resulting in bone on bone articulation of the facet joint.
Osteoarthritis and/or degenerative disc disease are wear-and-tear conditions that may lead to the formation of osteophytes (bone spurs) and/or to facet joint hypertrophy (enlarging and swelling of the facet joint). As these degenerative changes in the spine occur, the space in the spinal canal may become narrowed. The narrowing, called stenosis, may result in irritation of your spinal nerve roots, and radiculopathy (pain going down your arm or leg).
One important approach to preventing or managing these conditions with it is to exercise regularly. Exercise increases spinal flexibility, which helps reduces stiffness. It also strengthens your muscles which will protect the facet and other joints in the spine. Of course, you should ask your doctor for a complete treatment plan for your facet joint condition.
Whiplash and Facet Joint Pain
Facet pain after a car accident is not unusual. Two studies done by Barnsley and Lord in the mid-1990s and published in Spine found chronic facet joint pain to be a common, if not the most common, symptom in people who had experienced whiplash. This type of facet joint pain may feel like muscle tenderness on either side of the center of the spine. (That’s where the facet joints are located.) If you’ve been involved in an auto accident or any other trauma where your spine was subject to whiplash, please see your doctor. Getting an acute spine injury checked and treated early is absolutely key to avoiding a chronic pain condition that may last years and rob you of your quality of life.
Injections are used to both diagnose and treat facet joint pain. One such injection, called a medial branch block, is regarded by some as the only definitive way to tell if your spine pain is caused by damage to the facet joint. Your doctor will inject a local anesthetic into the area. If that relieves your pain, she may diagnose you with a facet joint problem. A 2008 review of medical studies published in Pain Physician that looked at the usefulness of medial branch blocks for diagnosing and treating facet pain found moderate evidence of both long and short term relief. Still, the use of such injections tends to be limited to confirming that your pain indeed comes from the facet joints.
An injection known as a radiofrequency medial branch neurotomy is often given for long term pain relief. Also called RF neurotomy, this type of injection heats the medial branch of the nerve that goes to the facet joint, deadening it. The idea is to block any pain signal coming from the facet joint, but clinical evidence that this actually works is unfortunately limited.
Usually an injection for facet pain is given only after you've tried four to six weeks of conservative treatment with little or no success.
The Medical Way to Say Facet
Doctors and anatomists often refer to facet joints as the zygapophysial joints. So if you see this term in your clinical report or diagnosis, know that it refers to the facet joints at the back of the spinal column.
Atluri S, Datta S, Falco FJ, Lee M. Systematic review of diagnostic utility and therapeutic effectiveness of thoracic facet joint interventions. Pain Physician. 2008 Sep-Oct;11(5):611-29.http://www.ncbi.nlm.nih.gov/pubmed/18850026
Boswell MV, Colson JD, Sehgal N, Dunbar EE, Epter R. A systematic review of therapeutic facet joint interventions in chronic spinal pain. Pain Physician. 2007 Jan;10(1):229-53. http://www.ncbi.nlm.nih.gov/pubmed/17256032
Kuhlman KA. Cervical range of motion in the elderly. Arch Phys Med Rehabil. 1993 Oct;74(10):1071-9. http://www.ncbi.nlm.nih.gov/pubmed/8215859
Lord SM, Barnsley L, Wallis BJ, McDonald GJ, Bogduk N. Percutaneous radio-frequency neurotomy for chronic cervical zygapophyseal-joint pain. N Engl J Med. Dec 5 1996;335(23):1721-6. http://www.ncbi.nlm.nih.gov/pubmed/8855458
Lord SM, Barnsley L, Wallis BJ, Bogduk N. Chronic cervical zygapophysial joint pain after whiplash. A placebo-controlled prevalence study. Spine (Phila Pa 1976). 1996 Aug 1;21(15):1737-44; discussion 1744-5. http://www.ncbi.nlm.nih.gov/pubmed/8855458
Manchikanti L, Boswell MV, Singh V, Pampati V, Damron KS, Beyer CD. Prevalence of facet joint pain in chronic spinal pain of cervical, thoracic, and lumbar regions. BMC Musculoskelet Disord. May 28 2004;5:15. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC441387/
UW Medicine. Orthopedics and Sports Medicine. Exercise and Arthritis. UW Medicine website. http://www.orthop.washington.edu/PatientCare/OurServices/Arthritis/Articles/ExerciseandArthritis.aspx Last updated: Tuesday, January 26, 2010.
Windsor, R. MD. et. al. Cervical Facet Syndrome. Medscape. Last Updated: May 24, 2011. http://emedicine.medscape.com/article/93924-overview#a0199