Pathologic changes in aging sacroiliac joints. A study of dissecting-room skeletons.

Pathologic changes of the sacroiliac joints were observed in 1986 skeletons from dissecting rooms in St. Louis, Missouri and Johannesburg, South Africa. In addition to being the largest population samples ever studied from this standpoint, these samples are the first to include blacks. Para-articular osteophytosis culminating in ankylosis is considered first, followed by the less common intraarticular changes that also occasionally culminate in ankylosis. Expressed as "average involvement" by decade, sex, laterality, and ethnic group, these joint changes are shown clearly to worsen progressively from the age of about 40 years. Osteophytosis especially becomes more common in black males, both American and African Bantu, than in American white males, and generally more common in males than in females. When occurring only (or mainly) unilaterally, the changes average out in favor of the right side, but only slightly. Joint mobility, or lack thereof, is assigned a large etiologic role.