Artificial joints are artificial organs designed on the basis of the development of metallurgy, biomaterials, biomechanics and orthopedic surgery to replace damaged and non-functional human joints for the purpose of relieving symptoms and improving function. Various artificial joints have been designed according to the characteristics of each joint in the body. Currently, artificial joints are the most effective artificial organs, and the artificial hip and knee joints are the most effective artificial joints. Other joints, such as artificial shoulder joints, elbow joints and ankle replacements, are also being developed. Artificial joints have been used to treat advanced joint disease since the 19th century. British doctors designed a hip prosthesis in 1962 that combined a metal femoral head with a polymer polyethylene acetabulum. Due to its advantages of low friction, stability and low loosening rate, the artificial hip joint replacement has been developed tremendously. To this day, the charnley artificial hip is still used as the “gold standard” against which other artificial hips are measured, and he is therefore recognized as the father of modern artificial joints. On the basis of the success of the artificial hip joint, other joints were studied in depth, and the artificial knee joint was first used in clinical practice. After more than 30 years of clinical practice, with the advancement of processing and material science, many types of artificial knee joints were introduced one after another. The efficacy of the artificial knee joint has been further improved, making it one of the most effective artificial organs available, and American doctors have made great contributions in this regard. Why Artificial Joint Replacement Artificial joint replacement is a procedure in which a joint that has lost function is repaired and a specific artificial joint is inserted to restore function, relieve pain, stabilize the joint, correct deformity, and improve joint motion. Artificial joints are very important for patients who have advanced joint destruction and for whom other treatments have failed. The advent of artificial joints has made it possible to cure many joint diseases that could not be treated in the past. It has enabled many patients with advanced joint damage who could only rely on crutches to walk like normal people, and has enabled some patients who were bedridden for a long time to regain their walking function and start a new life. The results of artificial joint replacement are determined by the patient’s confidence, the surgeon’s skill, bioengineering, and the design of the prosthesis and instruments. Over the past half century, artificial joint technology has evolved and been refined to become a major tool in the field of orthopedics for the treatment of advanced joint pathologies, and is considered a milestone in the development of orthopedics in the twentieth century. At present, artificial joint surgery has become a very successful procedure that can relieve and eliminate joint pain and restore joint movement. It allows people who have suffered from joint pain for a long time to walk, travel, work, shop and exercise as normal after surgery. Because of the certainty and predictability of the efficacy of artificial joint surgery, more patients are willing to undergo this surgery. Currently, about 550,000 people in the United States alone undergo artificial joint replacement surgery each year, and the number is increasing every year. What is an artificial hip joint and hip replacement An 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 strong 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, they are divided into 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 fracture, due to the high incidence of non-healing fracture and femoral head necrosis, it is also mostly advocated to make patients recover early through artificial joint replacement, live on their own and improve their life.