Spatial relationships between prevalent and incident spine fractures.

Women with prevalent fractures have an increased risk of developing additional, incident fractures. This article examines the relation between the location of prevalent fractures within the spine and the risk of subsequent vertebral fractures. The subjects were 721 Japanese-American women of mean age 69.5 +/- 5.3 (SD) years. For the analyses, the spine was categorized into three regions: an upper region, vertebrae T3-11; a middle region, vertebrae T-12 and L-1; and a lower region, vertebrae L2-5. Initial analyses were limited to women with, at most, one prevalent fracture. Compared to women without fracture, women with a prevalent fracture had odds ratios of 2-5 for developing an incident fracture outside the prevalent region. Subsequent analyses included women with multiple prevalent fractures. Women having two or three prevalent fractures had odds ratios of 7-9 for developing an incident fracture outside the prevalent region. The results suggest that the increased fracture risk of women with prevalent fractures extends beyond nearby vertebrae, and can affect vertebrae both above and below the prevalent fracture.