According to the American Academy of Orthopaedic Surgeons (AAOS), osteoarthritis of the knee typically occurs in knees that have experienced trauma, infection or injury. Other risk factors also increase the chances of developing knee arthritis.

Trauma and Injury

People who have had either traumatic injuries to the knee, including sports injuries, or repetitive stress injuries are more likely to develop knee arthritis. Jobs that are likely to cause repetitive stress knee injuries involve kneeling or squatting, walking more than two miles a day, or lifting at least 55 pounds regularly.

Job and Sports Risks

The AAOS reports that assembly line workers, computer keyboard operators, performing artists, shipyard or dock workers, miners and carpet or floor layers more often get osteoarthritis in the knee. Athletes in high-impact sports such as soccer, long-distance running and tennis also are more likely to develop knee arthritis.

Physical Factors

According to the AAOS, women older than 50 are more likely to develop knee osteoarthritis than men. Age, in general, is a risk factor because aging knee cartilage has less ability to heal itself. Also, weight increases pressure on the knee joints, so heavy people are at greater risk. Heredity also might be a factor.

Illnesses

People who have repeatedly had gout or septic arthritis, metabolic disorders and some congenital conditions are at higher risk.

Other Risk Factors

According to the AAOS, researchers are investigating other risk factors, including the effects of vitamins C and D, poor posture or bone alignment, lack of aerobic fitness and weak muscles.

Source:

AAOS: Frequently Asked Questions about Osteoarthritis of the Knee

University of Maryland Medical Center: Osteoarthritis Risk Factors