More-than-minimal-trauma fractures are associated with low bone density: an 8-year prospective study

Few studies have examined the relationship between more-than-minimal-trauma fractures and bone density. This study demonstrated that more-than-minimal-trauma fractures are associated with lower bone density similar to that seen in minimal trauma fractures. Men and women over 50 years with a more-than-minimal-trauma fracture should be investigated to exclude low bone density. The aim of this study was to assess the prevalence and predictors of low bone density in men and women with more-than-minimal-trauma fractures. In an Australian hospital, 630 community-dwelling men and women, 20 years of age or older, sustained a fracture due to more-than-minimal-trauma (force greater than a fall from standing height but less than high trauma). We studied 349 individuals who agreed to have a bone mineral density (BMD) scan. These participants were compared with 472 men and women with minimal trauma fractures. Men and women with more-than-minimal-trauma fractures had significantly lower bone density than expected for their age, gender and weight (Z-score(spine) = -0.4 SD, 95 % confidence interval (CI), -0.5 to -0.3; Z-score(hip) = -0.5 SD, 95 % CI, -0.6 to -0.4). Almost 1 in 4 of those over 50 years of age had osteoporosis by BMD criteria. The independent predictors of low bone density (T-score <-2.0 SD) were age equal to or over 50 years (odds ratio (OR) = 5.97, 95 % CI, 3.34 to 10.65), low body weight < 20 kg/m(2) (OR = 3.44, 95 % CI, 1.32 to 8.94), a prior minimal trauma fracture (OR = 2.76, 95 % CI, 1.17-6.52) and in those over 50 years of age, an osteoporosis-associated condition (OR = 4.51, 95 % CI, 1.69 to 12.06). Men and women with more-than-minimal-trauma fractures had similar bone density (Z-score) compared to those with minimal trauma fractures. Men and women over 50 years with a more-than-minimal-trauma fracture, especially those with low body weight, prior minimal trauma fracture or an osteoporosis-associated condition, should be investigated to exclude low bone density and its associated risk of subsequent fractures.