Risk factors for the development of osteoarthrosis of the knee.

The roles of physical activity (both work and leisure time), obesity, and history of significant knee injury on the development of severe osteoarthrosis (OA) of the knee were evaluated. A case-control design compared 46 cases with a history of severe OA of the knee with 46 community controls matched for age and gender. Data were gathered with a self-administered questionnaire. The OA cases were 3.5 times more likely than controls to have been obese at 20 years of age, two to three times more likely than controls to have performed heavy work, and almost five times more likely than controls to have had a significant knee injury. In contrast, leisure-time physical activity was not significantly different in cases compared with controls. Obesity, significant knee injury, and long-term heavy physical activity are important risk factors for the development of OA of the knee.