The bony structures that allow your back and neck to easily move in different directions are called "facet joints." Facet joints provide about one-fifth of your lower back and neck's twisting stability. Facet joints are located in pairs at each vertebral level (except for the top vertebra) down your spinal cord.
The surfaces of facet joints are coated with slippery cartilage, allowing them to glide freely as you move. Each joint is encased in a capsule that generates lubricant for the joint while it moves.
When joints are injured in a traumatic event, or degenerate over time because of the aging process or disease, a wide variety of problems and pain often result.
Facet joint syndrome develops when the cartilage in joints wears thin. Your body begins producing material (called bone spurs) to shore up the cartilage. This material can calcify, or harden, causing stiffness in the joint. In some cases, facet joint syndrome can contribute to joint inflammation, muscle spasms, and later osteoarthritis. Advanced cases of facet joint problems can lead to degenerative spondylolisthesis, a condition in which joints slip forward.
Facet joint disorders in the lower back can cause stiffness, and make it difficult to stand straight or get out of a chair. Facet joint disorders in the cervical (neck) region can cause headaches and difficulty rotating the head.
A common joint disorder involves the sacroiliac joint, which links the bottom of the spine with the pelvic bone. This joint endures a lot of pressure and absorbs the shocks from the upper body. Although it is a very strong and mostly stationary joint, the sacroiliac joint can become damaged or impaired. Sacroiliac joint dysfunction can mimic many of the symptoms of a herniated lumbar disc. People with sacroiliac joint dysfunction typically complain of pain on one side of their lower back or buttocks. The pain can sometimes shoot down one or leg or both, sometimes extending all the way down to the foot.