Osteoarthritis of the facet joints involves the breakdown of cartilage between these joints, resulting in pain and reduced range of motion.
Various factors can contribute to the development of facet joint osteoarthritis, including the wear and tear of day-to-day movements, prior injuries to the facet joints, inflammatory processes, and even genetic factors.
Once the protective layer of cartilage becomes damaged or worn away, movement within the spine causes friction, or rubbing, between the vertebrae, which results in inflammation.
Ongoing inflammation in the area of the facet joints can then cause the synovial membrane, which provides lubrication to the joint, to become thickened; when the membrane is thickened, it is less able to lubricate the facet joints, resulting in more friction, and therefore more inflammation, in the joint.
These degenerative changes to the cartilage and synovial membrane surrounding a facet joint can also result in damage to the bone itself.
As the vertebrae move against each other, no longer protected by the smooth and lubricated barrier of cartilage and synovial membrane, the resulting friction can result in the development of excess bone growth, called bone spurs.
Bone spurs then result in increased friction in the facet joints. The degenerative changes then become cyclic: damage to the cartilage, synovial membrane, and the bone itself results in increased friction and inflammation, which then results in increased damage to the tissues.