Hip axis length and non-hip cortical fragility fractures in young postmenopausal nonobese Caucasian women

Abstract

Introduction: Although measuring bone mineral density (BMD) with dual X-ray absorptiometry (DXA) represents the standard of diagnosis and management of osteoporosis, there is a significant number of fragility fractures occurring in young patients without low BMD. Recently, clinical risk tools included hip axis length (HAL), a geometric parameter derived from the hip DXA scan, as a predictor of hip fractures in older postmenopausal women. This study aims to evaluate the relationship between HAL and other cortical bone fractures in young postmenopausal, clinically healthy women.

Materials and methods: This study is a retrospective analysis of Lunar DXA scans of 206 normal or overweight Caucasian women aged 40-60, who had less than 10 years of menopause without secondary causes of osteoporosis, no prior osteoporosis diagnosis or medication, and no history of hip or vertebral fractures.

Results: The 15 fractured women displayed statistically greater HAL values compared to the 191 non-fractured subjects (109.43 ± 6.44 vs 104.81 ± 5.32 mm, p = 0.002), even though there were no significant differences in age, body mass index, or BMD. The difference in HAL remained significant after adjusting for lumbar spine (LS) BMD and height (108.49 ± 1.23 vs 104.88 ± 0.34 mm, p = 0.005). HAL proved to be a fair indicator of non-hip, non-vertebral cortical fractures (area under curve = 0.720, p = 0.003), with a sensitivity of 86.7% and a specificity of 55.5%.

Conclusion: HAL was positively associated with non-hip, non-vertebral cortical bone fragility fractures in young postmenopausal, clinically healthy women and had significantly greater values in the fractured subgroup even after adjusting for LS BMD and height.

Keywords: cortical bone; fragility fractures; hip axis length; osteoporosis; postmenopause.

Figure 1.

Estimated means of HAL for the fractured and non-fractured subgroups. HAL, hip axis length.

Figure 2.

ROC for HAL as an indicator of non-hip, non-vertebral cortical bone fragility fractures. HAL, hip axis length; ROC, receiver operator characteristics.