Femoral neck BMD is a strong predictor of hip fracture susceptibility in elderly men and women because it detects cortical bone instability: The Rotterdam study
Femoral neck BMD is a strong predictor of hip fracture susceptibility in elderly men and women because it detects cortical bone instability: The Rotterdam study
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DOI：
10.1359/jbmr.070712
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发表时间：
2007-11-01
影响因子：
6.2
通讯作者：
Pols, Huibert A. P.
中科院分区：
文献类型：
--
作者：
Rivadeneira, Fernando;Zillikens, M. Carokf;Pols, Huibert A. P.
我们研究了4806人（2740名女性）的HSA测量与髋部骨折风险的关系。髋关节骨折（n = 147）发生在两种性别的骨不稳定的绝对水平相同。皮质不稳定性（倾向较薄的皮质在宽直径屈曲）解释了为什么髋部骨折的风险在不同的BMD水平是相同的跨sexuals.Introduction：尽管骨的性别二型性，髋部骨折的风险是非常相似的男性和女性在相同的绝对BMD。我们的目的是阐明骨的主要结构特性的基础上测得的骨密度，并最终确定老年男性和女性的髋部骨折的风险。材料和方法：本研究是鹿特丹研究（一个大型的前瞻性人群为基础的队列）的一部分，包括147个事件髋部骨折的情况下，4806名参与者与DXA衍生的髋关节结构分析（平均随访，8.6年）。与骨折相关的指标包括颈宽、皮质厚度、截面模量（弯曲强度指标）和屈曲比（皮质骨不稳定指标）。我们使用一个数学模型来计算股骨颈BMD、BMC、骨面积和髋关节结构分析（HSA）参数的髋部骨折分布（皮质厚度、截面模量、窄颈宽度和屈曲比），并将其与来自鹿特丹研究的前瞻性数据进行比较。在前瞻性数据中，两种性别的髋部骨折病例在基线时BMD较低，皮质较薄，骨宽度较大，强度较低，不稳定性较高。在骨折的个体中，男性的平均BMD比女性高0.09 g/cm（2）（p < 0.00001），而屈曲率没有显著差异。通过BMD和屈曲比水平模拟的骨折分布与前瞻性数据一致，并显示男性和女性髋部骨折似乎发生在相同的骨不稳定（屈曲比）绝对水平。BMD（女性0.8146，男性0.8048）和屈曲比（女性0.8161，男性0.7759）的ROC曲线下面积无显著性差异。结论：屈曲比（骨不稳定性指标）反映了男女皮质厚度和骨宽度之间的临界平衡。我们的研究结果表明，膨胀骨中皮质的极度变薄对局部骨折的易感性起着关键作用。尽管屈曲比不能提供额外的预测价值，但这些发现提高了我们对为什么低BMD是脆性骨折的良好预测因子的理解。
We studied HSA measurements in relation to hip fracture risk in 4806 individuals (2740 women). Hip fractures (n = 147) occurred at the same absolute levels of bone instability in both sexes. Cortical instability (propensity of thinner cortices in wide diameters to buckle) explains why hip fracture risk at different BMD levels is the same across sexes.Introduction: Despite the sexual dimorphism of bone, hip fracture risk is very similar in men and women at the same absolute BMD. We aimed to elucidate the main structural properties of bone that underlie the measured BMD and that ultimately determines the risk of hip fracture in elderly men and women.Materials and Methods: This study is part of the Rotterdam Study (a large prospective population-based cohort) and included 147 incident hip fracture cases in 4806 participants with DXA-derived hip structural analysis (mean follow-up, 8.6 yr). Indices compared in relation to fracture included neck width, cortical thickness, section modulus (an index of bending strength), and buckling ratio (an index of cortical bone instability). We used a mathematical model to calculate the hip fracture distribution by femoral neck BMD, BMC, bone area, and hip structure analysis (HSA) parameters (cortical thickness, section modulus narrow neck width, and buckling ratio) and compared it with prospective data from the Rotterdam Study.Results: In the prospective data, hip fracture cases in both sexes had lower BMD, thinner cortices, greater bone width, lower strength, and higher instability at baseline. In fractured individuals, men had an average BMD that was 0.09 g/cm(2) higher than women (p < 0.00001), whereas no significant difference in buckling ratios was seen. Modeled fracture distribution by BMD and buckling ratio levels were in concordance to the prospective data and showed that hip fractures seem to occur at the same absolute levels of bone instability (buckling ratio) in both men and women. No significant differences were observed between the areas under the ROC curves of BMD (0.8146 in women and 0.8048 in men) and the buckling ratio (0.8161 in women and 0.7759 in men).Conclusions: The buckling ratio (an index of bone instability) portrays in both sexes the critical balance between cortical thickness and bone width. Our findings suggest that extreme thinning of cortices in expanded bones plays a key role on local susceptibility to fracture. Even though the buckling ratio does not offer additional predictive value, these findings improve our understanding of why low BMD is a good predictor of fragility fractures.