Male osteoporosis with vertebral fractures? Look for ankylosing spondylitis! A report of 10 cases.

Abstract

Several authors have described the association of ankylosing spondylitis (AS) and osteoporosis. Usually vertebral fractures complicate severe AS. We report a series of 10 men in whom benign spondyloarthropathy was discovered during etiological investigation for osteoporosis. Eight patients had B27+ AS and 2 had psoriatic arthritis with axial involvement. The mean number of vertebral fractures was 1.5. No patient had an appendicular fracture. Phosphorus and calcium levels and measurements of 25OHD3, parathyroid hormone, osteocalcin, and serum CTX were in the normal range. The decrease in bone mineral density was greater in the spine (mean T-score at L2-L4 -2.95, mean total hip T-score -1.67). Osteoporosis with fractures may reveal benign spondyloarthropathy whose clinical expression is sometimes incomplete. Our findings demonstrate that osteoporosis is not always correlated with the severity of AS.