Currently, we are able to perform arthroplasty of the hip, knee, shoulder and elbow joints. The first total hip arthroplasty was performed in 1960, and since then, with the development of surgical techniques and surgical materials, the results of total hip arthroplasty have improved significantly. It is reported that approximately 168,000 total hip replacements are performed each year in the United States. The surgery takes about 2-3 hours to remove the diseased bone and cartilage and place a metal or plastic prosthesis to restore the force line and joint function of the lower extremity. The main surgical indications are arthritis and hip fractures, including osteoarthritis, rheumatoid arthritis, traumatic arthritis, and femoral neck fractures. The most common joint replacements are hip and knee. Hip replacement: If your condition meets the following points, you should generally have a hip replacement: 1. The pain in the hip joint has limited your daily activities, such as walking and bending; 2. The hip pain exists whether you rest during the day or night; 3. The stiffness of the hip joint prevents you from walking or lifting your leg; 4. The reduction in hip pain after taking anti-inflammatory medication is very mild; 5. There are serious side effects or feel very uncomfortable after taking the medication; 6.After other treatments, the hip pain cannot be reduced. After total hip replacement, more than 90% of patients have significant improvement in their symptoms, a significant reduction in hip pain, and a significant improvement in their ability to perform daily activities. Most patients with hip replacements can start standing and walking with the help of a walker the day after surgery under the guidance of their doctor. The likelihood of complications after total hip arthroplasty is low. The incidence of some serious complications has been reported to be less than 2%. Postoperative activities at home are crucial, especially during the first few weeks. It is generally said that recovery to the point of being able to perform daily activities is possible 3-6 weeks after surgery. Postoperative issues that should be taken care of: 1. prevent thrombosis; 2. prevent infection; 3. prevent falls; 4. do not do a planking motion; 5. do not flex the hip joint more than 90 degrees; 6. do not turn your foot inward or outward excessively; 7. put a pillow between your legs when you sleep at night. Knee joint replacement: Knee joint replacement is one of the most effective methods of treating advanced osteoarthritis and rheumatoid arthritis at home and abroad. The surgery removes the cartilage and diseased bone from the surface of the knee joint and replaces it with biological and metallic materials, avoiding direct friction between the bones of the knee joint during activities, thus not causing pain, achieving pain relief, increasing the range of motion of the knee joint, correcting deformities, and greatly improving the function of the knee joint and improving the patient’s quality of life. The placement of the artificial knee joint will not have adverse effects on the human body and will not endanger human health. After a lot of clinical practice, it has been proved that artificial knee joint replacement is the best choice for the treatment of advanced osteoarthritis.