Ankylosing spondylitis arthritis Ankylosing spondylitis belongs to the category of rheumatic diseases and is one of the seronegative spondyloarthropathies. Studies have shown that the cause of the disease is not very clear, the spine is the main lesion of the chronic disease, the lesion mainly involves the sacroiliac joint, causing spinal ankylosis and fibrosis, resulting in bending, walking activity is limited, and can have varying degrees of eye, lung, muscle, bone lesions, but also autoimmune disorders, so also belong to the autoimmune disease. The main features of AS are inflammation and ossification of the lumbar, cervical and thoracic spinal joints and ligaments, as well as the sacroiliac joints, often involving the hip joint, and inflammation of other peripheral joints. Ankylosing spondylitis is actually a very ancient disease, with evidence of ankylosing spondylitis found in the bones of ancient Egyptians thousands of years ago. 2000 years ago, Hippocrates, a famous Greek physician, described a disease in which the affected person had pain in the sacrum, spine, and cervical spine. AS is common in young people aged 16-30 years and is more common in males, with first onset after age 40 years being rare, accounting for about 3.3% of cases. The disease starts insidiously, progresses slowly, and has mild systemic symptoms. In the early stage, there is often lower back pain and morning stiffness, which decreases after activity, and can be accompanied by low fever, fatigue, loss of appetite, wasting and other symptoms. The pain is intermittent at the beginning and develops into persistent after several months and years. Later, the inflammatory pain disappears, the spine is partially or completely straightened from the bottom up, and a hunchback deformity appears. In female patients, peripheral joint invasion is more common and progresses more slowly, and the spinal deformity is less severe. 1. The etiology of AS is not yet known. The incidence of the disease is low, more males than females, and there is a significant family history, so patients with AS are considered to have a genetic component. Studies have shown that AS is closely related to HLA-B27, and that the development of ankylosing spondylitis is directly related to HLA-B27. The underlying pathology is a primary, chronic, vascular cataract-destructive inflammation, mainly of the synovium, joint capsule, tendons, and bone attachment points of ligaments. Ossification is secondary to the repair process. 2, manifestations of peripheral arthropathy in ankylosing spondylitis About half of the patients with AS have transient acute peripheral arthritis, and about 25% have permanent peripheral joint damage. It generally occurs more often in large joints, and more in the lower extremities than in the upper extremities. The rate of peripheral joint involvement has been estimated to be 40% for the hip and shoulder, 10% for the knee and ankle, 5% for the foot and wrist, and rarely for the hand. The main manifestations are limitation of movement, flexion contracture, muscle atrophy, and joint ankylosis. 3, diagnosis (1) X-ray examination is of great importance to the diagnosis of AS, most cases have X-ray changes of sacroiliac joint at an early stage, which is an important basis for the diagnosis of the disease. The typical X-ray manifestation is the bamboo-like change of spine and the change of pelvic closed hole pattern. (2) Laboratory tests: blood sedimentation will increase accordingly, C-reactive protein will be significantly higher, immunological tests will have different manifestations, and serum creatine phosphokinase is often elevated; more than 90% to 95% of AS patients are HLA-B27 positive.