Due to the research progress in biomechanics and material science, the rapid development of artificial joints has been promoted. The prosthesis design, surgical operation technique, perioperative treatment and postoperative rehabilitation of artificial joints have become more and more perfect and mature, and the success rate of surgery has been greatly improved, with an excellent rate of more than 97% at 10 years after surgery and 90%-93% at 20 years, which greatly encouraged orthopedic surgeons to apply artificial joints to treat joint diseases and injuries. More patients have confidence in the excellent results of artificial joint replacement and are willing to accept artificial joint replacement. Which diseases are suitable for artificial joint replacement or which diseases will achieve better results with artificial joint replacement? This article is divided into two parts: First, the diseases suitable for artificial hip replacement 1, hip fracture ① femoral neck fracture with displacement, the older. ② old fracture of femoral neck, due to various reasons of delayed treatment or conservative treatment after the fracture does not heal or ischemic necrosis of the femoral head. (iii) Traumatic ischemic necrosis or collapse of femoral head, which occurs after treatment of femoral neck fracture. (iv) Those who have existing lesions in the hip joint before femoral neck fracture, such as osteoarthritis, rheumatoid arthritis or ischemic necrosis of the femoral head. ⑤ Pain and dysfunction secondary to osteoarthritis, osteonecrosis and joint deformity after acetabular fracture. 2.Osteoarthritis of the hip joint (or osteophyte) Patients with osteoarthritis of the hip joint who suffer from night pain and the effect of painkillers is not good, which affects their work and life. 3.Femoral head ischemic necrosis Hormonal or alcoholic or idiopathic femoral head ischemic necrosis patients, the femoral head has collapsed, pain, dysfunction. 4.Hip dysplasia or hip dislocation Middle-aged and old people suffering from hip dysplasia or hip dislocation, pain in the affected hip or lumbar pain or pain in the healthy side of the hip or knee. Total hip replacement can be considered. 5, rheumatoid arthritis rheumatoid arthritis hip pain, drug effect is not good or hip deformity, dysfunction. 6, ankylosing spondylitis ankylosing spondylitis hip joint lesion, drug effect is not good, or hip deformity, dysfunction. 7, Hip joint infection, surgery, residual joint ankylosis after surgery Hip ankylosis appears lower back pain, knee pain on the same side or pain on the opposite side of the hip, knee joint. Pseudo-fusion with pain or non-functional fusion after hip fusion surgery. 8. Other diseases of hip joint, which are invalid by conventional treatment. Diseases suitable for artificial knee joint replacement 1, knee osteoarthritis (or osteophytes) Knee osteoarthritis pain aggravated by the effect of drugs is not good. 2.Traumatic osteoarthritis of knee joint After trauma or meniscectomy, the pain of knee joint is diagnosed as traumatic hip osteoarthritis, and the effect of medicine is not good. 3.Rheumatoid arthritis, rheumatoid arthritis pain in knee joint, the effect of drugs is not good or joint deformity, dysfunction. 4, knee joint infection, trauma, residual joint ankylosis after surgery knee joint due to septic infection or tuberculosis infection, trauma, residual joint ankylosis after surgery to appear lower back pain or the healthy side of the hip or knee pain; knee fusion surgery after pseudo-fusion with pain or non-functional fusion. 5, other diseases of the knee joint Modern artificial joint replacement technology is the twentieth century orthopedic surgery, a revolutionary progress, especially the application of artificial hip, knee replacement, can quickly relieve pain, quickly get out of bed activities, reduce the serious complications of long-term bed rest and mortality, improve the quality of life of patients. When we apply this high-tech technology, we should also be soberly aware of the fact that any surgery is subject to complications. In order to maximize the benefits and minimize the damages, doctors should strictly control the application of surgery, standardize the operation and actively prevent and control complications to achieve better long-term results and benefit the patients.