The facet joint, also known as the zygapophysial joint, is a movable joint located between the inferior and superior articular processes of the vertebra. Each vertebra contains two facet joints. These joints allow for spine mobility, and help a person bend forward, stand straight, and rotate left and right.
Facets joint degeneration occur due to age or through injury. The cartilage tissue around these joints erode or tear. When this happens, the bones rub together, restricting movement of the spinal column and compressing the spinal nerve roots housed in the spinal canal underlying the spinal column.
Spinal nerve root compression results in severe pain. The pain remains localized at first, but as the amount of pressure exerted on the spinal nerve roots by the bones increases, the pain spreads and soon causes loss of mobility.
Age related degeneration of facets joints is a natural process that cannot be reversed. It is, however, possible to ease the pressures on the spinal nerves, and consequently alleviate the pain through facetectomy, an invasive surgical procedure. Facetectomy surgery removes one or more facets to preserve nerve functioning.
Image Credit: flickr.com/Vet Moves