The chronic form is inflammation of the joints, which primarily affects the spine. This inflammation permanently affects the bones of the spine. Ankylosing spondylitis is one of the autoimmune disorders associated with rheumatoid arthritis. Early signs of ankylosing spondylitis include back pain, especially after waking up. The pain often intensifies at night, and over time stiffness and pain may spread to the back, shoulders, and pelvis. As the condition progresses, other symptoms may include loss of spinal flexibility and range of motion, contracted chest movement (from inflammation of the joints connecting the ribs to the spine), fatigue, and a hunchbacked or bent posture.
Ankylosing spondylitis is a type of chronic rheumatic disease that mainly affects the spine and sacroiliac joints (the sacroiliac joint is the joint between the sacrum and the pelvis). Spondylitis means inflammation of the spine, and ankylosing spondylitis means that the bones tend to stick together. Ankylosing spondylitis causes the vertebrae in the spine to heal.
In ankylosing spondylitis, the ligaments around the spine become inflamed at the junction of the vertebrae. In other words, the source of ankylosing spondylitis is inflammation of these ligaments. This inflammation stimulates the bone-forming cells and bone is made inside the ligaments, and after a while the ligaments turn into bone.
Gradually, these bones become larger, and because the ligaments themselves are connected to the adjacent vertebrae from all around, the bones created inside the ligaments connect like a bridge between adjacent vertebrae and connect the vertebrae. After a while, the vertebrae of the spine are connected and the movement between them disappears. The same thing happens with the sacroiliac joints, causing the sacroiliac joints to fuse. (The sacroiliac joint is located between the sacrum and the ilium and is located behind the pelvic ring).
Therefore, the main site of activity of ankylosing spondylitis is the spine and sacroiliac joints. Of course, some other joints in the body can also be involved in the process of this disease, the most important of which is the hip joint.
Ankylosing spondylitis usually starts between the ages of 15-35 and is 3-5 times more common in men than women. There may be a history of similar cases in the patient’s family. The prevalence of ankylosing spondylitis is about one in a thousand.
The main cause of ankylosing spondylitis is not well understood but it has a genetic background. 90% of these patients have a gene called HLA-B27, while this gene is found in only 10% of healthy people.
Spinal fusion in a radiograph of an ankylosing spondylitis patient
The presence of this gene in a person’s body is used as one of the laboratory symptoms of the disease. Of course, the presence of this gene in a person’s body is not always a sign that he is ill. Ankylosing spondylitis is usually a progressive disease.