Genetic background increases the risk of hip osteoarthritis.

Using a cohort of 49 families with at least one affected female sibling pair who had total hip arthroplasty for end-stage primary osteoarthritis, we determined the prevalence and relative risk of symptomatic and radiographic osteoarthritis in 145 children. The relative risk of symptomatic radiographic osteoarthritis in these 145 offspring was 3.5 times greater than in 119 age-matched controls (95% confidence interval; range, 2.0-6.2). Most symptoms and radiographic changes involved the hip. Results of this study showed vertical transmission of primary osteoarthritis and that genetic influences play a major role in osteoarthritis of the hip in the Caucasian population.