What types of artificial joints are there? How long do they usually last? In the past, the commonly used artificial joint was a metal head to polyethylene interface, which produced metal debris and polyethylene debris, and this debris caused the bone to dissolve, resulting in loosening of the prosthesis. There have been some advances in artificial joints, for example, the metal head has become a ceramic head. The new generation of ceramic interface has wear-resistant characteristics, unlike metal, which has metal debris, but some people are concerned that ceramic is more brittle, but the current ceramic head is also entering its fourth generation, and the brittleness of ceramic has been well improved. The polyethylene part is gradually being changed to highly cross-linked polyethylene, which is also very wear-resistant. In addition, the diameter of the femoral head of the current artificial joint has been increased. The conventional femoral head diameter used to be 28 mm, but now it is 32 mm or 36 mm. What are the benefits of an enlarged femoral head? On the one hand, the joint is more stable and less prone to dislocation, and on the other hand, it is better able to withstand forces. If the artificial joint is well done (well done means that the prosthesis is well positioned, well pressed, and has a good bone length), and if the patient uses it properly, the utilization rate can reach 85% to 90% or even better in 20 years. The price of different types of artificial joints is different, is the more expensive the better? In general, ceramic-to-ceramic interfaces are the most expensive, ceramic-to-highly cross-linked polyethylene interfaces are the next most expensive, and metal-to-polyethylene interfaces are the least expensive. However, the more expensive is not the best. There is a consensus that a ceramic-to-ceramic interface or a ceramic-to-polyethylene interface may be more appropriate for younger patients, and that a metal-to-polyethylene interface may be appropriate for older patients, such as those over 70 years of age. However, the success and longevity of the surgery depends not only on the interface material, but also on the surgeon’s surgical technique, the extent of the lesion, the postoperative use, and the presence of complications. High-priced artificial joints do not compensate for the lack of surgical technique, but rather, ordinary artificial joints based on excellent surgical technique can last for a long time. How should a patient who has had an artificial joint replacement take care of the joint? Are they still unable to bear weight, sit on a low stool or squat, or use a squatting toilet (seated toilets only)? Generally speaking, although many doctors say that patients can play various types of sports after surgery, in fact, because these artificial joints are inorganic materials, they are not living organisms and have no metabolism. Therefore, although there are many reports that patients can play various types of sports such as skiing, hockey, basketball, soccer, etc. after surgery, excessive strenuous exercise will accelerate the wear and tear of the joints. Of course, this also depends on the individual’s pursuit of life, and there is no clear rule that one must not do the types of sports that ordinary people usually participate in on a daily basis. As for the problem of squatting on the toilet, because of the large diameter of the femoral head at present, the stability of the joint is better, and theoretically it is possible to squat. However, as a doctor, because there is still a local injury and risk of joint dislocation after surgery, we suggest that patients should not squat too much, especially in the early post-operative period and elderly patients. Of course, most of our patients who have had hip replacement surgery can squat, but I don’t recommend it because no one knows how much the patient can squat, and there is still a certain risk of dislocation if the patient exceeds the limit. Therefore, we recommend that hip replacement patients should not squat as much as possible, and should not perform cross-legged movements. However, for most patients, it is still possible to put on socks and squat occasionally to pick up things, but it is important to note that these movements should be done only after a longer period of time, for example, 3 months or 6 months or even a year after the surgery, and the specific time and range of functional activities should be recommended by the surgeon in charge, taking into account the surgery and the patient’s specific situation. How can I tell if the surgery was successful? Does the fact that some patients still walk with a slight limp or pain after surgery indicate that the surgery was unsuccessful? The success of the surgery can be judged by clinical manifestations and imaging. Through imaging analysis, such as X-ray photos or CT scans, we can observe the position and angle of the joint prosthesis and whether the two lower limbs are equal in length. Generally speaking, the hip joint is different from the knee joint. After hip replacement, if the imaging shows good results, the results are usually good. However, some patients may still feel some discomfort, which is possible because even if the artificial joint is not replaced, as long as the soft tissue is damaged by the operation, the patient may have discomfort. As long as there are not serious complications such as infection, loosening of the prosthesis, sinking of the prosthesis, dislocation, etc., it can be gradually improved. Of course, it is true that there is a situation that in the early postoperative period, the patient continues to feel very uncomfortable for three months or six months, which is most likely related to the surgical technique, for example, it may be that the prosthesis is not well positioned or is not playing steady, but during the examination, because the time after surgery is not yet long, the imaging may not yet reveal obvious abnormalities, but in fact the prosthesis may already have loosened. In this case, dynamic observation and, if necessary, CT examination may reveal the problem. In addition, although artificial hip surgery is a mature surgery, there are some potential surgical risks, such as infection, dislocation, prosthesis loosening, deep vein thrombosis, and unequal lower extremity length. Therefore, every aspect and detail such as strict mastery of surgical indications, careful perioperative evaluation and complication prevention and control, excellent surgical techniques, and reasonable rehabilitation must be done strictly in order to guarantee the success of the surgery.