Bacterial Infection
Some scientists think, as stated above, that specific type of bacteria attack the body and cause inflammation and swelling around the bones, joints, tendons, and ligaments. HLA-B27 may have something to do with this inflammation, but to confirm the link, more research work is required.
Inflammation in the body – and particularly chronic inflammation as in ankylosing spondylitis can cause it to release chemicals and proteins that can damage soft tissues around it, such as fascia and cartilage. The damaged tissue is substituted by scar tissue that can cause more pain as it does not safeguard the joint as does cartilage. As a consequence of the impact of ankylosing spondylitis on the body, the scar tissue can then harden and form fresh bone.
This new bone formation process is called ossification, and bone develops where it shouldn’t be in patients with AS. Bony spurs restrict the mobility and flexibility of your spine and may lead to spinal compression fractures and bent bone.