Prediction of hip and other osteoporotic fractures from hip geometry in a large clinical cohort
Incident hip fractures and non-hip osteoporotic fractures were studied in 30,953 women during mean 3.7 years of observation. Hip axis length (HAL) and strength index (SI) made a small but statistically significant contribution to hip fracture prediction that was independent of age and hip bone density.
It is uncertain whether bone geometric measures improve fracture prediction independent of conventional areal bone mineral density (BMD).
Women aged ≥50 years with hip dual-energy x-ray absorptiometry were identified from the regionally based database in the Province of Manitoba, Canada. Scans were reprocessed to derive parameters of hip bone geometry. Incident hip fractures (N = 270) and non-hip osteoporotic fractures (N = 1,347) were identified during mean 3.7 years of observation.
HAL was greater in both hip and non-hip fracture cases than in non-fracture cases, whereas cross-sectional moment of inertia, cross-sectional area, and femoral SI were all significantly less. After adjustment for total hip BMD, HAL [hazard ratio (HR) 1.22 per SD increase, 95% CI 1.07–1.38] and SI (HR 1.21 per SD decrease, 95% CI 1.07–1.37) were independent predictors of hip fractures but not of non-hip fractures. When both HAL and SI were added to a model containing age and total hip BMD, there was a small improvement in hip fracture prediction (ROC area under the curve 0.832 ± 0.013 vs 0.823 ± 0.013; P = 0.001).
HAL and SI made a small but statistically significant contribution to hip fracture prediction that was independent of age and BMD measurement.
KeywordsBone geometry Bone mineral density Dual energy X-ray absorptiometry Fractures Hip axis length Hip structure analysis
We are indebted to Manitoba Health and Healthy Living for providing data (HIPC no. 2003/2004-26). The results and conclusions are those of the authors, and no official endorsement by Manitoba Health and Healthy Living is intended or should be inferred. This article has been reviewed and approved by the members of the Manitoba Bone Density Program Committee. This study is funded in part by an unrestricted educational grant from the CHAR/GE Healthcare Development Awards Programme.
William D. Leslie:
Honoraria or speaker’s fees: Merck Frosst Canada, Sanofi-Aventis, Genzyme Canada Ltd. Research support and unrestricted educational grants: Merck Frosst Canada, Procter & Gamble Pharmaceuticals, Amgen Canada, Genzyme Canada Ltd.
Payam Pahlavan, James F. Tsang, Lisa M. Lix:
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