The facet joints are located between neighboring vertebrae, behind the vertebral bodies. They help stabilize the spine, helping prevent the vertebra from slipping forward and also keeping the spine from twisting too far or extending back too much.
The facet joints help control spine movements such as:
Twisting and rotation
Individual vertebrae are connected to one another by pairs of facet joints—two above and two below. Each facet joint is comprised of:
An inferior articular process: A downward bony projection that comes from the vertebra above
A superior articular process: An upward bony projection that comes from the vertebra below
The flat surfaces of these processes touch and glide against one another. With the help of ligaments, the 24 individual spinal bones connect together to make a column.
The facet joints in different areas of the spine are shaped, sized, and oriented differently. These differences contribute to varying flexibility in different areas of the spine.
Facet joints in the cervical spine (neck) are adapted for a range of movements.
In the thoracic spine (upper and mid-back) facets are angled to facilitate limited rotation, turning, and twisting.
In the lumbar area (lower back), the facet joints face each other, limiting your ability to rotate and twist your low back.
The facet joint is a synovial joint, which means that it’s enclosed by a capsule made of connective tissue. The capsules of the facet joints are aptly named facet joint capsules.
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 facet damage was responsible for 55% of the cases. Two of the most common problems that cause facet joint pain include osteoarthritis and whiplash.
Facet Joint Hypertrophy and Arthritis
The bones of the facets are normally lined with cartilage, which cushions the joint. With osteoarthritis of the spine, the cartilage may wear out, resulting in bone on bone articulation at 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 progress, the space in the spinal canal and/or neural foramen may develop stenosis (become narrow). Narrowing of your spinal canal may result in irritation of your spinal cord, and narrowing of the neural foramen can impinge or irritate your spinal nerve roots. Spinal cord irritation cause symptoms of myelopathy, and nerve root irritation can cause radiculopathy (radiculopathy is often felt as pain and nerve symptoms that go down an arm or leg).
Exercise increases spinal flexibility, which helps reduces stiffness. It also strengthens your muscles, which can help protect the facet and other spinal joints. Of course, you should ask your doctor for a complete treatment plan for your facet joint condition before starting on an exercise regimen.
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 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, 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, see your doctor promptly. Getting an acute spine injury checked and treated early is absolutely key to avoiding serious spine damage or a chronic pain condition that may last years and rob you of your quality of life.
Injections can help in both the diagnosis and treatment of facet joint pain.
A medial branch block is often regarded as the only definitive way to determine whether 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, you might be diagnosed 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.
A radiofrequency medial branch neurotomy (RF neurotomy) is often used for long-term pain relief. 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 limited.
Usually, an injection is considered only after you've tried four to six weeks of conservative treatment, with little or no success.
The Medical Way to Say Facet
Sometimes facet joints are referred to 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.