<P> In the United States, there were approximately 964,000 hospitalizations for osteoarthritis in 2011, a rate of 31 stays per 10,000 population . With an aggregate cost of $14.8 billion ($15,400 per stay), it was the second-most expensive condition seen in U.S. hospital stays in 2011 . By payer, it was the second-most costly condition billed to Medicare and private insurance . </P> <P> Evidence for osteoarthritis found in the fossil record is studied by paleopathologists, specialists in ancient disease and injury . Osteoarthritis has been reported in fossils of the large carnivorous dinosaur Allosaurus fragilis . </P> <P> Osteoarthritis is derived from the Greek word part osteo -, meaning "of the bone", combined with arthritis: arthr -, meaning "joint", and - itis, the meaning of which has come to be associated with inflammation . The - itis of osteoarthritis could be considered misleading as inflammation is not a conspicuous feature . Some clinicians refer to this condition as osteoarthrosis to signify the lack of inflammatory response . </P> <P> There are ongoing efforts to determine if there are agents that modify outcomes in osteoarthritis . Sprifermin is one candidate drug . There is also tentative evidence that strontium ranelate may decrease degeneration in osteoarthritis and improve outcomes . </P>

Which of the following is a factor in the development of osteoarthritis