Ankylosing spondylitis is a type of autoimmune disease that manifests as spinal ankylosis, sacroiliac joint ankylosis, and later, hip ankylosis. When the hip joint is in a non-functional position, such as a bent hip position or an inward position, the patient cannot walk upright, cannot see in front of him, cannot squat, cannot wear pants, cannot take care of himself, and can seriously affect the function of the respiratory, digestive, and cardiovascular systems, even endangering life and health, which must be treated by surgery and artificial joint replacement surgery in order to rebuild the function of the hip joint and allow the patient to stand upright and take care of himself. The patient can stand upright and take care of himself. The difficulty factor of this surgery is high and the risk of surgery is also high, therefore, the patient must choose a surgeon who is experienced and skilled to perform the surgery.