BONE-MINERAL DENSITY IN ANKYLOSING-SPONDYLITIS

Vertebral osteoporosis is a well-recognized feature of ankylosing spon dylitis (AS) and also the vertebral compression fractures due to osteo porosis are a common but frequently unrecognized complication of AS. B oth may contribute to the pathogenesis of spinal deformity and back pa in. The aim of this study was to measure vertebral and femoral neck bo ne mass in patients with AS by dual photon absorptiometry, to determin e the prevalence of compression fractures and to examine the relations hip between bone density and disease severity. We found that the bone mass was diminished in the lumbar spine in moderate AS versus mild for ms but the patients with advanced disease had the highest BMD values. Examination of spinal radiographs revealed compression and biconcave f ractures in 9 (40.9%) cases. Neither the duration of the disease and t he degree of sacroiliitis, nor the disease activity assessed by labora tory and clinical parameters was found to significantly affect the res ults.