The main population of hip replacement is the elderly patients with osteoarthritis, but many young patients with ankylosing spondylitis and rheumatoid arthritis often have no choice but to have hip replacement, in long-term contact with patients, I found that this relatively special group of young people, the most confused and most want to understand how to choose the materials and prosthesis for hip replacement, the following is my humble opinion on this issue. Hip replacement has a history of over 40 years, and the prosthesis and materials have evolved and updated over several generations. In terms of materials, we are talking about the friction interface of the artificial hip joint, which is the active interface between the artificial femoral head and the artificial acetabular lining. We often hear the phrase “metal to polyethylene”, which actually refers to the friction interface between the metal femoral head and the polyethylene acetabular liner, and the convention is that the material of the artificial femoral head is mentioned first, and then the material of the artificial acetabular liner. So, “ceramic to polyethylene” means ceramic femoral head to polyethylene liner, and “ceramic to metal” means ceramic femoral head to metal liner. Sometimes we hear the expression “metal to ceramic”, in fact, this statement is wrong, because literally means metal femoral head to ceramic liner, but in fact there is no such material interface, because it is easy to think that the metal femoral head will cause the ceramic liner to break, in fact, the correct statement should be “ceramic to metal”, that is, ceramic femoral head to metal liner, this material matching is feasible. The main ones widely used in the market are: metal to polyethylene, ceramic to polyethylene, ceramic to ceramic, metal to metal, in addition to this there is ceramic to metal, but this pairing is rarely used by doctors, so it is not discussed here for the time being. First of all, it should be noted that the oldest and most used material is metal-to-polyethylene, accounting for 80% of the market share. Although it is the least wear-resistant of the four materials in the appeal, the service life of the supramolecular highly cross-linked polyethylene currently in use has increased dramatically compared to the traditional polyethylene in the past after the polyethylene production process was improved, and a theoretical service life of 15-20 years can be fully expected. The biggest advantage of this material is that it is inexpensive and can be shaped into irregular shapes, so it is often designed with an additional “anti-dislocation high side”, which is popular among surgeons, because if the surgeon finds that the posterior top of the acetabulum is not stable enough during surgery, he can put this “anti-dislocation high side” into the acetabulum. If the surgeon finds that the posterior aspect of the acetabulum is not stable enough, he or she can put the “anti-dislocation high side” on the posterior aspect of the acetabulum to increase the stability, which is a remedy for surgical errors if the acetabulum is not placed well enough. The larger the diameter of the femoral head, the less likely it is to dislocate and the better the postoperative mobility. Therefore, according to the size of the femoral head diameter, all materials are matched with the difference between large and small femoral heads. The artificial femoral head with a diameter greater than 32 mm is a large diameter femoral head, and if the patient uses a large diameter femoral head, theoretically the postoperative mobility is better than using a small diameter femoral head, and it is easier to do squatting and other movements. Domestic metal-to-polyethylene material only small diameter femoral head, the price fluctuates between 13,000 and 18,000, imported metal-to-polyethylene small femoral head prosthesis, the price is about 28,000 yuan, large diameter femoral head prosthesis price between 32,000 yuan and 38,000 yuan. If the patients are very tight financially, I think it is enough to use this material, even if it is domestic with 20 years is also very possible, if you want to move a little better, with a large diameter femoral head imported materials will be better. Ceramic-to-ceramic is the latest design and has only been clinically used for a dozen years, but in laboratory tests it is currently the most wear-resistant of all materials and can theoretically last 30 years or more, but whether it can really last that long has not yet been reported in living cases. The ceramic-to-ceramic design often allows patients to use a large diameter femoral head to achieve better joint mobility, which I think is its biggest advantage, so for those patients with a medium-sized pelvis that is not particularly large or small, I recommend using this material, because patients with a particularly small pelvis even if they use this material if their acetabulum diameter is less than 48mm still can not use a large diameter femoral head But if a patient with an acetabular diameter of 52mm uses a ceramic-to-ceramic prosthesis, he can use a 36mm, 36mm oversized femoral head prosthesis, which will be significantly different from a 28mm small diameter femoral head. The advantage of excellent mobility will be fully realized. However, ceramic has its drawbacks, mainly the problem of fracture and rattling. Ceramic wear does not mean that it is hard enough to resist violence, although fragmentation is not a frequent occurrence, but some patients with a high level of exercise and car accidents may still have this situation, and the rattling, that is, the hip joint will emit a harsh sound when walking, this situation is less likely to occur, but it is not clear why, and can not yet be completely eliminated, therefore limiting the ceramic to ceramic materials on a large scale. applications. Therefore, I personally recommend this material for young patients of medium size who are not particularly active, so that they can take advantage of its durability and mobility and reduce the chance of adverse events. Usually, the 4th generation ceramic-to-ceramic material on the market costs around $65,000, and there is no domestic ceramic-to-ceramic material available yet. Metal-to-metal materials used to be a popular concept a few years ago, but have become very controversial in recent years. Theoretically, metal-to-metal material has both wear-resistant properties similar to ceramics and is hard enough to overcome the shortcomings of ceramic fragmentation, making it easier to achieve large diameter femoral head applications, although it also has theoretical disadvantages of metal ion degradation penetrating into the bloodstream affecting kidney function and even placental transmission leading to malformations, but these are not enough to stop scholars from developing and applying it with enthusiasm. Unfortunately, in practice this material has not shown durability, and some authorities in the United States have found much higher than expected early loosening rates with this material and even called off some companies from recalling this product. Therefore, until further evidence emerges, I am on the fence about this material and do not recommend the material for now. The remaining ceramic-to-polyethylene is certainly a compromise product, not as abrasion resistant as ceramic-to-ceramic and not as active as metal-to-metal, but on the flip side, it also does not have the same obvious drawbacks as ceramic-to-ceramic and metal-to-metal, and is much better than traditional metal-to-polyethylene, so I personally tend to recommend this product at this stage. Although the theoretical longevity is not as good as ceramic-to-ceramic, a 20+ year lifespan is entirely expected. I personally believe that the activity of ankylosing spondylitis patients is generally not very large, the service life of the prosthesis after hip surgery should be longer, and the 20 years after surgery is often a critical period for them to work and get married, it is important to spend this period smoothly and unintentionally, the future of science is still progressing, I believe there will be better solutions, do not have to be too entangled must achieve the 30-year life of the prosthesis The service life, after all, this service life is still only the results of laboratory simulation, there is still to be the actual clinical verification. The price of this material is also relatively moderate, fluctuating in 38,000 – 45,000 yuan, mainly because some are used in the third generation of ceramic head, some are used in the fourth generation of ceramic head, there is also no domestic production of such products, the market circulation of all imported products. As for the choice of several generations of ceramic head, I think the 3rd generation has been very good, no need to blindly pursue the 4th generation of ceramic head. In practice life, I often encounter patients ask me “how long is the age of this material, how many years can be used?” I think this question is only a theoretical comparison of the problem, the overall durability of ceramic than metal, imported than domestic durable, but for the individual can not say that the imported can be used for 20 years, domestic can only use 15 years. Like the use of cars, some imported cars will be scrapped in 10 years, some domestic cars can also be driven for 20 years, so in addition to comparing the service life of the car, in addition to the quality of the car to consider how to use the car, how to maintain and drive mileage problems. Artificial joints are the same, the maintenance and activity after surgery also determine the service life of the material, more importantly, the surgery must be done well enough to achieve the premise of the life of the prosthesis should be. Many patients have problems with the most expensive imported materials within a few months after surgery, while some patients who use the cheapest domestic materials have no problems for twenty years. Therefore, if the patients want to choose, the main thing is to choose the surgeon in charge, followed by how to use correctly after surgery, and finally the question of what material to choose. If the surgery is done well, even if the artificial joint is made in China, the results can be just as good. I am not saying that using a domestic or imported one is the same, but for the same surgeon, using imported materials will certainly produce better results because the tools are more precise and smooth, and the product design is more advanced. What I mean is that if the economy is very tight, patients who cannot afford to use imported materials do not have to worry too much, good doctors do not have any major problems with domestic materials, and in many cases are very good. I’m not bragging about myself, I feel very confident doing domestic materials, although it may be better to do imported materials, but patients who are financially strapped don’t have to wait until they have saved enough money for imported materials to do the surgery. All things are risky, and unnecessary waiting and delay sometimes bring far more harm than the advantages of using imported materials. In conclusion, I would like to say, young people with ankylosing spondylitis, artificial hip replacement is a very mature technical tool, no matter what material you use, you may get good postoperative results and productive life, the most important thing is to gather your courage to live, face the disease and never give up, for the sake of your love and the people who love you!