Word: sockets
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Dates: during 1970-1979
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With its ball-and-socket arrangement, the hip appears to be a structurally simple joint. But to the patient, and to his orthopedic surgeon, a disease-damaged hip often presents appalling problems. Surgeons have for years been inserting workable mechanical substitutes, but too often the substitute has failed, either because of faulty wearing surfaces, or because of infection that later requires the removal of the whole artificial joint...
Behind His Back. When a hip joint is damaged, the ball of bone at the head of the femur may rub against the roughened surface of the socket in the hip proper (see diagram), causing severe and immobilizing pain. Replacing the head of the femur with a stainless steel ball (just under an inch in diameter for the average patient) is relatively easy. The difficulty is to secure the ball to the femur. In early operations, the shaft holding the ball was screwed into the femur. Charnley was dissatisfied with the method because the shaft sometimes came loose. A dentist...
That was only half of the mechanical problem. The ball must rotate in a socket, which in most such hip operations had been made of steel. Charnley disliked the steel-to-steel joint because it must be lubricated solely by body fluids, which are often inadequate. A plastic socket would require no lubrication. But what plastic? He tried Teflon, only to have it break loose and damage nearby bone. "One day," he says, "a salesman turned up with a sample of high-density polyethylene. I sent him away, telling him that we knew that polyethylene was useless. I hadn...
...years. But Solheim's claim is at least indirectly supported by other evidence of Southeast Asia's prehistoric culture. At the historic Thai village of Non Nok Tha, another University of Hawaii archaeological team has discovered a 3,500-year-old metal ax with a socket for a handle. The unusual implement may show that Thailand's ancient people were able to make tools as sophisticated as those of their Middle Eastern contemporaries, and were probably working with bronze at least 1,000 years before the Chinese-who were previously thought to have taught them the skill...