Macrotrauma and repeated microtrauma are the most common causes of secondary osteoarthritis. Although being active and maintaining good muscle condition is probably protective for joints, sports and activities that involve excessive trauma to joints result in accelerated osteoarthritis. Ballet dancers, for example, are virtually unique in their occupational risk for ankle osteoarthritis. The sport that has the highest likelihood for development of premature osteoarthritis is football, with approximately 100% of players affected if they play for 7 years or more.
