Osteoarthritis of the hip and occupational activity.

This case-referent study investigated the relation between hip osteoarthritis and occupational activity. The subjects were 60- to 75-year-old men who had undergone intravenous urography. Interviews were obtained for 245 cases who had a hip replacement for osteoarthritis or a joint space of less than or equal to 2.5 mm and 294 referents whose joint space was greater than or equal to 3.5 mm in both hips. No clear associations were found in an analysis of all the cases, but severe disease (hip replacement for osteoarthritis or a joint space of less than or equal to 1.5 mm) was more common in the farmers, especially in those with greater than or equal to 10 years in agricultural work [odds ratio (OR) 2.0, 95% confidence interval (95% CI) 0.9-4.4]. Severe disease was also associated with prolonged standing at work (OR 2.7, 95% CI 1.0-7.3) and heavy lifting (OR 2.5, 95% CI 1.1-5.7). These associations could not be explained by obesity or sporting activity. The findings suggest an increased risk of degenerative hip disease for farmers and indicate that mechanical overloading may contribute to its pathogenesis.