There are many forms of arthritis such as Ankylosing spondylitis, reactive arthritis, psoriatic arthritis, juvenile spondyloarthropathy, enteropathic arthritis, Rheumatoid arthritis, Gout, infectious arthritis, poly myalgia rheumatica, osteoporosis.
However the most common form of arthritis found in the low back is osteoarthritis. It is a chronic condition demonstrable by the breakdown of cartilage that cushions the ends of the bones where they meet to form joints.
In the spine, this breakdown occurs in the cartilage of the facet joints, where the vertebrae join. As a result, movement of the bones can cause irritation, further damage and the formation of bony outgrowths called spurs. These spurs can press on nerves, causing pain. New bone formation can also lead to narrowing of the spinal canal, known as spinal stenosis.