Sacro-Iliitis in Eight Populations

Abstract

From the adult males from 8 populations (1750 pelvic X-rays) were compared for the presence of sacro-iliitis of the kind associated with classical ankylosing spon-dylitis. A high prevalence of these changes was considered to be present in the Haida Indian films and in those from 1st degree male relatives of patients with ankylosing spondylitis. All other populations had significantly fewer changes. Methods of sampling, criteria used in film grading, and various methods of comparison are described. The Haida Indians had an inordinately high prevalence of sarco-iliitis, probably due to ankylosing spondylitis. When all the populations were compared there seemed to be geographical differences in the prevalence of ankylosing spondylitis.