Multidisciplinary Osteoporosis Research Program, Women's College Hospital, Toronto, ON, Canada; Department of Exercise Sciences, University of Toronto, Toronto, ON, Canada.
Multidisciplinary Osteoporosis Research Program, Women's College Hospital, Toronto, ON, Canada; Department of Medicine, University of Toronto, Toronto, ON, Canada.
J Clin Densitom. 2014 Jan-Mar;17(1):170-6. doi: 10.1016/j.jocd.2013.02.003. Epub 2013 Mar 9.
Genetic, environmental, or hormonal factors may cause heterogeneity in skeletal load response. Individuals with reduced sensitivity to load should require higher strains to generate an adaptive response, consequently have weaker bones and fracture more frequently. The purpose of our study was to determine if stresses (proportional to strains) at the femoral neck under equivalent loads were higher in women with a history of fractures compared with women without fractures. We studied postmenopausal women participating in the Canadian Multicentre Osteoporosis Study who had available hip structure analysis data from dual-energy X-ray absorptiometry scans (n = 2168). Women were categorized into 2 groups based on their number of self-reported fractures. We computed stress (megapascals) at the inferomedial margin of the femoral neck in a one-legged stance mode using a 2-dimensional engineering beam analysis. We used linear regression (SAS 9.3) to determine associations between stress, geometry parameters, and number of fractures. Postmenopausal women with 1 or more fractures had higher stress (2.6%), lower narrow neck bone mineral density (4.2%), cross-sectional area (3.9%), and section modulus (9.6%) than postmenopausal women without fractures (all p < 0.05). These findings provide evidence of heterogeneity in load response and suggest an important role for modeling in the pathogenesis of osteoporotic fracture.
遗传、环境或激素因素可能导致骨骼负荷反应的异质性。对负荷敏感性降低的个体应该需要更高的应变才能产生适应性反应，因此骨骼较弱，骨折更频繁。我们研究的目的是确定在同等负荷下，股骨颈的应力（与应变成比例）在有骨折史的女性中是否高于无骨折史的女性。我们研究了参加加拿大多中心骨质疏松研究的绝经后妇女，她们的双能 X 射线吸收仪扫描有可用的髋部结构分析数据（n=2168）。根据报告的骨折次数，将女性分为 2 组。我们使用二维工程梁分析在单腿站立模式下计算股骨颈内下边缘的应力（兆帕）。我们使用线性回归（SAS 9.3）来确定应力、几何参数和骨折数量之间的关联。有 1 次或多次骨折的绝经后妇女的应力（2.6%）较高，窄颈骨矿物质密度（4.2%）、横截面积（3.9%）和截面模量（9.6%）较低，与无骨折的绝经后妇女相比（均 p < 0.05）。这些发现提供了负荷反应异质性的证据，并表明建模在骨质疏松性骨折的发病机制中起着重要作用。
