Prevalence of primary coxarthrosis in siblings of patients with primary coxarthrosis.

The prevalence of primary coxarthrosis was investigated in 289 siblings of 184 patients treated by total hip replacement. Age and sex-matched persons from the city files of Malmö, Sweden, were selected as controls. The prevalence of presenting symptoms (initiating a hip roentgen examination) of primary coxarthrosis in the siblings was 8%, compared to 3.8% in the controls (p less than 0.05). The type and localization of primary coxarthrosis was evenly distributed between the two groups. Conversely, the prevalence of gonarthrosis did not differ between the two groups. The prevalence of primary coxarthrosis in the siblings suggests the influence of a hereditary factor in the etiology of primary coxarthrosis.