Osteoarthritis is a condition in which the cartilage that protects and cushions the joints breaks down over time. Eventually, the bones-formerly separated by the cartilage-rub against each other, resulting in damage to the tissue and underlying bone and causing painful joint symptoms. When osteoarthritis affects the small joints in the spine, it can lead to back pain. Osteoarthritis in other joints, such as the hips, can cause us to limp or to change the way we walk. This can also lead to back pain.