Osteoarthritis of the Spine

Osteoarthritis develops when the small joints at each motion segment in the spine, called facet joints, degenerate and no longer function correctly.

The condition involves:

• Inflammation of the joints in the back or neck, called facet joints
• A breakdown of the cartilage in the facet joints
• Abnormal bony growths on the spine, called osteophytes or bone spurs
• Abnormal motion in the affected motion segments

This osteoarthritic process usually occurs slowly over the course of several years.

The resulting pain, stiffness, and other symptoms may come and go or be constantly present.

Here is an in-depth guide about spinal osteoarthritis and the degenerative spine conditions associated with it, including symptoms, diagnostic process, and treatments.

How Arthritis Develops in the Back or Neck

This type of arthritis usually occurs due to internal damage to the facet joints. The facet joints can become painful through the following process:

• The cartilage on one side of the facet joint gets damaged. Every time the spine moves the injured cartilage rubs against its neighbor, causing friction and further injury to both sides.
• The joint damage and friction lead to inflammation.
• The swollen facet joints transmit this pain signal through a small nerve (the medial branch) that travels through and innervates the facet joint.
• This signal can then cause the back muscles to go into spasm as a means of trying to protect the joint.
• The combination of muscle spasm and inflammation of the joints causes low back pain or neck pain.

Arthritis is Common in Certain Spinal Segments

Certain areas of the spine are more susceptible to developing facet joint degeneration.

It tends to develop in the spinal segments that have the most motion:

• In the lower back, it tends to develop in the lowest two motion segments, the L4-L5 and L5-S1 segments
• In the neck, it is most common in the C6-C7 motion segment, followed by C5-C6¹Kuo DT, Tadi P. Cervical Spondylosis. [Updated 2020 May 16]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK551557/?report=classic

The joints in the middle of the spine (thoracic spine) have a restricted range of motion and are less likely to develop painful osteoarthritis.

How Spine Osteoarthritis Causes Pain

Spine osteoarthritis can lead to significant pain and stiffness due to:

• The friction at the facet joints tends to lead to inflammation, which causes pain.
• The osteoarthritic changes at the spinal motion segments can trigger muscle spasms.  Any type of back muscle spasm can be surprisingly painful.
• Bone spurs and/or enlarged facet joints that develop may impinge upon the spinal cord and nerve roots, causing radicular symptoms such as pain, tingling, and numbness down the arm (for cervical osteoarthritis) and leg (for low back osteoarthritis).
• Other related changes, such as synovial cysts, may form near the facet joint capsules. These cysts may impinge on nerve roots and cause radicular pain and/or neurological symptoms.

Arthritis in the back or neck is often mild, but when the pain and stiffness become chronic and limit your ability to do everyday activities, it can become more serious and should be treated.

It is normal for the spine to show signs of degeneration over time, and not everyone who has signs of osteoarthritis feels symptoms. In addition:

• Cartilage does not contain nerves, so damaged cartilage is not a source of pain.
• Bone spurs (osteophytes) are normal signs of aging, and these often to not cause pain.

When Spine Osteoarthritis Is Serious

Severe spinal osteoarthritis is typically accompanied by degenerative disc disease, spinal stenosis, or both.

These conditions may be serious because they can lead to the compression of the spinal cord or its nerve roots, causing one or more of these symptoms:

• Severe lower back or neck pain that prevents most daily activity, including sleep
• Nerve pain – a type of sharp, shooting, and burning pain -- in the leg(s) (due to low back arthritis) or arm(s) (due to cervical arthritis)
• Progressive weakness in the leg(s) or arms(s)
• Numbness or tingling in the hands or feet
• Loss of bowel and/or bladder control (either inability to retain or release)

The loss of bowel and/or bladder control accompanied by one or more other symptoms may indicate a rare medical emergency called cauda equina syndrome and warrants emergent medical attention.

Osteoarthritis of the Spine: Many Names, One Disease

Osteoarthritis that develops in the spine can go by many different names, including:

• Facet joint arthritis
• Facet joint syndrome
• Facet arthropathy
• Zygapophyseal joint arthritis
• Z joint arthritis
• Back arthritis or neck arthritis (or osteoarthritis)

It may also be referred to by terms that describe general degenerative changes in the spine, such as:

• Facet joint disorder, which refers to any disease process in the facets, most commonly osteoarthritis
• Spondylosis, a general term that refers to any spine pain caused by degeneration, including but not limited to osteoarthritis

Regardless of the term used, spinal osteoarthritis is common. Most people over the age of 60 shows signs of osteoarthritis in their spines, though most do not experience pain.