Arthritis is a term that indicates inflammation of the joints. A joint is an articulation between bones that provides stability along with varying types and degrees of motion. The joints of the vertebrae, called facet joint, are synovial joints.

These joints contain a membrane that secretes a synovial fluid, a lubricating liquid of eggwhite consistency (synovial is derived from the Greek word for egg white) that allows motion. The articular surfaces are also covered with cartilage that is flexible and elastic. In a normal condition, the synovial fluid lubricates the joint; when arthritis occurs, the joints became dry and painful, due to increased friction in the joint. Arthritis may originate from different conditions, such as injury, ageing process, overload or damage of the tissues surrounding the joints.