Adult congenital hip dislocation, also known as adult acetabular dysplasia, is a congenital developmental abnormality that is a common cause of hip pain and an important causative factor in osteoarthritis of the hip joint. It is generally considered to be more prevalent in women than in men, with a male to female ratio of approximately 1:5, and a family history exists in ¼ of patients. In a normal hip joint, the bowl-shaped acetabulum covers the spherical femoral head well, and there is some cartilage and joint capsule between the acetabulum and the femoral head to serve as a stabilizer. When the acetabulum is dysplastic, the acetabular bowl becomes shallow and turns outward, causing it to be less inclusive of the femoral head, which tends to shift outward and upward, resulting in subluxation. In a normal hip joint, the femoral head is well covered by the acetabulum and there is articular cartilage between the acetabulum and the femoral head. When the acetabulum is dysplastic, the acetabulum becomes shallow and the coverage of the femoral head becomes poor, and the femoral head tends to dislocate outward and upward, resulting in subluxation or complete dislocation. Performance: In cases of incomplete dislocation, there may be no discomfort in the early stage. Generally, at the age of 20-40, hip fatigue, soreness, swelling and vague pain appear with the wear and tear of walking. As the disease progresses, joint pain worsens and limping and pain at rest occur. As the femoral head shifts outward and upward, the affected limb becomes shorter and the leg may limp when walking. Treatment principles: 1. Patients with less severe pain should be treated as conservatively as possible: reduce joint weight bearing, avoid physical labor and strenuous exercise. 2. Patients with severe pain but not osteoarthritis: surgery can be performed to increase the bony coverage of the femoral head to delay the progression of osteoarthritis. There are many surgical methods, such as acetabular osteotomy, peripheral rotational osteotomy, internal displacement osteotomy, acetabular osteotomy, etc. 3, late stage patients are often accompanied by severe osteoarthritis, most of the articular cartilage is bad, the acetabulum and femoral head of bone proliferation, joint space narrowing or even disappear. At this time, the joint pain is severe and joint movement is limited. The aim of treatment is to relieve pain and restore joint movement. At this time, the first choice for treatment is total hip arthroplasty, which is a very mature technology at present.