Osteoarthritis in young adults is most commonly a result of a previous injury to the knee. Deconditioning of the musculoskeletal system is seen with joint injury, obesity, and aging, all known risk factors for osteoarthritis. Muscular deconditioning contributes to increased joint loads and knee osteoarthritis development and progression. So far, it is unclear whether surgery reduces the development or progression of osteoarthritis. The risk for osteoarthritis development seems to increase as the amount of meniscal tissue removed increases. Knee injury prevention, rehabilitation after knee injuries, regular exercise, maintaining body weight, and a changed locomotion pattern may prevent osteoarthritis initiation and progression in young adults.