arthritis
The spine is composed of five regions – cervical (neck), thoracic (midback), lumbar (low back), sacrum (buttock), and coccyx (tailbone). The cervical spine consists of eight bones, called vertebrae. The thoracic spine has 12, the lumbar spine has five, the sacrum has five which are fused together, and the coccyx has four smaller fused bones. Except for the sacrum and coccyx, every level of the spine consists of a functional structural unit consisting of two vertebrae and a disc, which is made of cartilage and water. The vertebrae sandwich a disc in front, but also form two small joints in back called zygapophyseal (facet) joints. This unit allows the spine to withstand forces while allowing for movement, including bending and twisting. At younger ages, discs are well hydrated and there is good spacing between the bones and their joints.
Due to age and other factors, the water in a disc can dissipate, and the disc shrinks in size (one of the reasons why we get shorter when we get older). As the disc space narrows, so does the facet joints’, and in turn they compress more. As a result, more stressful forces are transmitted through these structures. To compensate for and to adapt to these forces, new bone formation can occur. However, new bone can then invade spaces usually relegated for the neural structures of the spine, including the spinal cord and nerve roots. These neural structures can be compressed, resulting in sensory or motor symptoms, such as pain, numbness, tingling, imbalance and/or muscle weakness. Patients may also have localized pain if pain is emanating only from the facet joints. This continuum of changes that occur to the spine as we get older is called osteoarthritis.
There is nothing that can be done to prevent arthritis from occurring, just like a grey hair or a wrinkle in your skin cannot be prevented. HOWEVER, even though these arthritic changes become more common with age, and can be a source of pain, arthritis does not always lead to pain. As a matter of fact, a lot of people have arthritis, yet do not have any symptoms resulting from it. Therefore, if arthritis shows up on x-rays, it does not have a catastrophic meaning. It is simply a medical term that can mean that there are typical age-related changes to the spine.