Spinal osteoarthritis is the wear-and-tear arthritis of the spine. Osteoarthritis is the common form of arthritis in which a joint’s smooth cartilage gradually thins and the bone reacts by forming small spurs. In the spine, it affects the facet joints, the small paired joints at the back of each level that guide movement. It is also called spinal arthritis, and, in medical terms, spondylosis, which is the word most often used on scan reports and in referral letters.
It is very common, and largely a normal part of ageing: by later life most people have some osteoarthritic change in the spine, and much of it causes no symptoms at all. For most people it is not serious. It matters when the wear produces a specific problem, such as a nerve compressed by stenosis, facet joint pain that will not settle, or a segment that has become unstable. Spinal osteoarthritis is really an umbrella term for the age-related wear of the spine, and it overlaps closely with several conditions covered in depth elsewhere, facet joint pain, disc degeneration, and the nerve compression that wear can cause. Those are set out further down, and on their own pages.