The artificial hip joint consists of a femoral prosthesis and an acetabular prosthesis. The prosthesis consists of a metal alloy with good compatibility with human tissue and a wear-resistant polymer polyethylene liner. The femoral prosthesis consists of a ball part and a dry body part. The ball part is made of a smooth and sturdy alloy, and the body part is mostly tapered and can be inserted into the bone marrow cavity of the upper part of the human femur, which is tightly integrated with the femur, and the head and the body part can be assembled together. The other part is the socket part which is integrated with the pelvis. It is lined with a polymer polyethylene liner and forms a smooth and wear-resistant joint with the metal ball head. Artificial hip replacement is the replacement of a diseased hip joint with an artificial prosthesis. Artificial hip replacement can be divided into total hip replacement, which is a simple replacement of the femoral head, and total hip replacement, which is a simultaneous replacement of the acetabulum and the femoral head. Depending on the fixation method, there are cemented and non-cemented (biologically fixed) types. The cemented total hip joint consists of three parts: a polyethylene acetabular prosthesis, a metal ball head and a metal femoral stem prosthesis. The non-cemented total hip joint consists of four parts: a metal outer cup, a polyethylene liner, a metal or ceramic ball head, and a metal femoral stem prosthesis. The type of artificial joint and the fixation method should be chosen by the surgeon according to the patient’s age, hip pathology and bone condition. What diseases require artificial hip replacement Total hip replacement surgery is suitable for those who suffer from hip joint destruction, joint pain and movement disorders caused by diseases or injuries, which seriously affect daily life and quality of life and cannot be relieved and improved by conservative treatment. The common ones are hip joint destruction, pain and functional limitation caused by femoral head necrosis, osteoarthritis, ankylosing arthritis, rheumatoid arthritis and traumatic arthritis. There are also congenital hip dislocation, acetabular dysplasia, secondary osteoarthritis caused by old dislocation or subluxation of the hip joint. For elderly patients with displaced or subhead type elderly femoral neck fractures, due to the high incidence of non-healing fracture and femoral head necrosis, it is also mostly advocated to enable patients to recover as soon as possible through artificial joint replacement, live a self-care life and improve the quality of life.