No space -- meaning no cartilage between the two bones that make up the knee joint -- can cause tremendous pain.

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The tribunal heard that Prof Richardson had used a piece of equipment used to blow air into the knee joint, which he had modified specifically for the operation.

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It can be caused by a number of factors, including a rapid increase in the frequency of training, sudden increase in the intensity of training, transition from one training method to another, genetic abnormalities of the knee joint and poor base strength of the quadriceps.

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The polymers can be used in just about any form of product from hydrogels and solutions to coatings for things like hospital equipment and even replacement joints (infections from contaminated hip, knee, and other joint replacements have been on the rise recently).

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After years of robust financial health, artificial knee- and hip-joint maker Stryker ( SYK) has suffered aches and pains the last couple years.

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Conventional wisdom holds that the pounding from years of running leads to excessive wear and tear on the body as we age, resulting in joint injuries, knee replacements or arthritis.

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For example, its Arthroscopy products are used in the repair of soft tissue joint injuries, particularly the knee and shoulder.

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Joint-captain Chris Cusiter travelled despite a persistent knee injury preventing him from playing in the 24-5 win over a Japan Select on Tuesday.

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For skiers, knee injuries are the most likely, accounting for a quarter of all injuries, where the joint is twisted and the ligaments are stretched or torn.

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