Facet joint

The facet joint or zygapophysial joint is a set of synovial, plane joints between the articular processes of two adjacent vertebrae. There are two facet joints in each spinal motion segment. The function of the facet joint is to guide and limit movement of the spinal motion segment.

Etymology

The term "facet" comes from the French "facette" (little face), and the term "zygapophysial" comes from the Greek "zygon" (yoke) and "physis" (process).

Anatomy

The facet joints are formed by the superior and inferior articular processes of each vertebra. The superior articular process faces upward and the inferior articular process faces downward. The joint is surrounded by a joint capsule and is filled with synovial fluid.

Function

The facet joints work together with the intervertebral discs to support the spine and allow for movement. They also prevent excessive movement such as hyperextension or hyperflexion.

Clinical significance

Facet joint syndrome, also known as osteoarthritis of the spine, is a common cause of back pain. It is caused by degeneration of the facet joints, which can result in inflammation, swelling, and pain. Treatment options include physical therapy, medication, and in some cases, surgery.

Related terms

• Vertebra
• Intervertebral disc
• Synovial joint
• Facet joint syndrome
• Osteoarthritis

Facet joint

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  Diagram of facet joints
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  Illustration of a facet joint injection
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  Animation of an AP endonuclease