The appearance of hip replacement changed this situation.
Hip joint refers to the joint between pelvis and femur, which is the most important joint in human body. Once the articular cartilage is polished and the joint head directly contacts the articular surface, the patient will suffer unbearable pain, and in severe cases, he can't walk at all, which seriously affects the quality of life of the patient.
Human beings have already figured out the joint structure, but it is not easy to replace a brand-new artificial joint, especially the hip joint that has eaten a lot. Since 1930s, some people tried to replace the hip joint, some used stainless steel, others used stronger cobalt metal, but the results were not satisfactory.
From 65438 to 0954, the annual plastic surgery conference was held in England, and some people listed the difficulties encountered in hip plastic surgery. A little middle-aged man stood up and said, "I don't think we should do this at all." According to the data you reported, the existing hip replacement has completely failed. It is better to saw off the patient's joints, connect the two ends and let them die. " Although this lost the ability to act, but at least it can not hurt! "
His name is John Charnley, and he is a plastic surgeon in England. That's not what he did. One of his patients once complained to him that the artificial hip joints he installed elsewhere always creaked at first, which made his wife always avoid him. After a few weeks, the noise disappeared, and the doctor who operated on him said that this was because the friction between the joints decreased.
Smart Charnley has a different view. He studied a knee joint that had just been amputated, and found that the friction coefficient of the joint surface was surprisingly 0.005, which was smaller than that of ice skates and ice. In his view, the initial squeak only shows that the artificial joint must be close to each other in order not to slide, and then the sound disappears because the joint is loose. Such joints can't last long. In order to get a wear-resistant joint, we must try to find an artificial material with low friction coefficient.
After 7 years of closed-door research, Charnley finally designed a brand-new artificial hip joint. He improved the original design in three aspects. First of all, he used a new material-Teflon, which is the surface coating for non-stick pan. Secondly, he improved the original fixing method. In the past, doctors used screws to fix artificial joints, but Charnley used acrylic cement instead. This cement-like substance distributes the stress of joints evenly throughout the bone, making the strength of joint fixation 200 times higher than that of screw method. Thirdly, he modified the parameters of artificial hip joint. In the past, doctors designed artificial joints according to the size of human joints, but Charnley didn't believe in evil. Through calculation, he found that the new material changed the characteristics of the joint, and the joint size must be reduced to make it stronger. So he reduced the size of the joint head and joint surface by about 1 inch, and the effect was much stronger than before.
196 1 year, Charnley published his new design in the famous magazine The Lancet, which initiated a new era of artificial joints.
However, a few years later, something new happened. Teflon has a small friction coefficient, but its wear resistance is not enough, so it will be replaced in a few years. In addition, Teflon can cause human rejection and joint swelling. Realizing the seriousness of the problem, Charnley stopped the operation and shut himself in the laboratory all day, trying to find a new substitute material.
One day, his assistant came and said that a salesman was selling him a new wear-resistant material for looms, called "HMWP". This new material has just been developed by a German company and has not been put on the market. Charnley drew a line on HMWP with his nails, and then sent his assistant away. But the young man named Harry craven didn't give up. He did the experiment in secret and found that HMWP was much better than Teflon, so he ran to Charnley's office again and asked his boss to try again. This time, Charnley believed his assistant's words and tested this instrument for three weeks without interruption. As a result, the wear degree of HMWP is only half that of Teflon.
With wear resistance, what are the characteristics of allograft rejection? Charnley decided to do the experiment with his own body. He put a small piece of HMWP on one arm and Teflon on the other. After several months, the place where PTFE was implanted was obviously swollen, but HMWP did not change at all.
Supported by the experimental results, Charnley began to operate again. In the following three years, he performed 500 hip replacement operations. After several years of follow-up, 92.7% of the patients were completely successful, which led to the publication of a new paper in 1972, reporting the benefits of this new material.
At this point, the story about hip replacement can come to an end. At present, at least in western countries, hip replacement has become a routine operation. In the United States alone, 300,000 people undergo surgery every year, creating a market value of $2 billion. More importantly, this operation has improved the quality of life of countless people, and the value of this operation is particularly important today with an aging population.
All this comes from the clever mind of that little surgeon 50 years ago. Charnley proved that human intelligence can be compared with the creation of nature. ■