Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA.
Osteoporos Int. 2012 Feb;23(2):513-20. doi: 10.1007/s00198-011-1569-2. Epub 2011 Feb 23.
We examined the relation between a biomechanical measure, factor-of-risk, and hip fracture risk in 1,100 men and women from the Framingham Study and found that it predicted hip fracture (men, ORs of 1.8; women, 1.2-1.4).
Alternative methods of predicting hip fracture are needed since 50% of adults who fracture do not have osteoporosis by bone mineral density (BMD) measurements. One method, factor-of-risk (Φ), computes the ratio of force on the hip in a fall to femoral strength. We examined the relation between Φ and hip fracture in 1,100 subjects from the Framingham Study with measured hip BMD, along with weight, height, and age, collected in 1988-1989.
We estimated both peak and attenuated force applied to the hip in a sideways fall from standing height, where attenuated force incorporated cushioning effects of trochanteric soft tissue. Femoral strength was estimated from femoral neck BMD, using cadaveric femoral strength data. Sex-specific, age-adjusted survival models were used to calculate hazard ratios (HR) and 95% confidence intervals for the relation between Φ (peak), Φ (attenuated), and their components with hip fracture.
In 425 men and 675 women (mean age, 76 years), 136 hip fractures occurred over median follow-up of 11.3 years. Factor-of-risk, Φ, was associated with increased age-adjusted risk for hip fracture. One standard deviation increase in Φ (peak) and Φ (attenuated) was associated with HR of 1.88 and 1.78 in men and 1.23 and 1.41 in women, respectively. Examining components of Φ, in women, we found fall force and soft tissue thickness were predictive of hip fracture independent of femoral strength (was estimated from BMD).
Thus, both Φ (peak) and Φ (attenuated) predict hip fracture in men and women. These findings suggest additional studies of Φ predicting hip fracture using direct measurements of trochanteric soft tissue.
我们研究了生物力学指标因素风险（Factor-of-risk）与弗雷明汉研究中 1100 名男性和女性髋部骨折风险之间的关系，发现其可以预测髋部骨折（男性，比值比为 1.8；女性，1.2-1.4）。
由于 50%的髋部骨折患者的骨密度（BMD）测量值并未诊断为骨质疏松症，因此需要寻找其他预测髋部骨折的方法。其中一种方法是因素风险（Φ），它计算了跌倒时作用于髋部的力与股骨强度的比值。我们研究了 1988-1989 年在弗雷明汉研究中收集的 1100 名有髋部 BMD 测量值、体重、身高和年龄的受试者的 Φ 与髋部骨折之间的关系。
我们从站立高度侧向跌倒时估算了作用于髋部的峰值和衰减力，其中衰减力包含了大转子软组织的缓冲效应。股骨强度使用股骨颈 BMD 从尸体股骨强度数据中估算。使用男女特定的年龄调整生存模型计算了Φ（峰值）、Φ（衰减）及其与髋部骨折之间关系的危险比（HR）和 95%置信区间。
在 425 名男性和 675 名女性（平均年龄为 76 岁）中，中位随访 11.3 年期间发生了 136 例髋部骨折。因素风险（Factor-of-risk）与髋部骨折的年龄调整风险增加相关。男性中，Φ（峰值）和Φ（衰减）每增加一个标准差，HR 分别为 1.88 和 1.78；女性中，HR 分别为 1.23 和 1.41。在女性中，进一步研究了Φ的组成部分，我们发现跌倒力和软组织厚度与股骨强度（由 BMD 估计）独立预测髋部骨折。
因此，Φ（峰值）和Φ（衰减）均可预测男性和女性的髋部骨折。这些发现表明，应使用直接测量大转子软组织的方法进一步研究Φ 预测髋部骨折。
