Hip Fracture Prediction by Combining Fall Risk, Impact Loads and Bone Strength

项目摘要 髋部骨折仍然是影响老年人的最具破坏性和代价最高的临床问题之一。每个人 在美国，超过30万老年人患有髋部骨折，高达25%的髋部骨折患者死于 他们受伤一年，髋部骨折占骨质疏松总成本170亿美元的72% 骨折。目前评估骨折风险的临床标准是骨密度。 采用双能X线骨密度仪(DXA)结合临床危险因素检测。然而，有一半的人 骨折发生在那些通过骨密度测试没有骨质疏松症和/或临床风险很小的人 因此，没有达到世卫组织骨折风险评估工具(FRAX)干预阈值。 尽管90%的髋部骨折都是由于跌倒造成的，但目前研究髋部骨折风险的方法确实是 不直接包括跌倒的概率或在跌倒过程中可能发生的骨骼负荷。我们的整体 目标是通过使用生物力学框架来改善髋部骨折风险的预测 跌倒的风险、跌倒造成的冲击载荷和股骨强度。在一项前瞻性病例队列研究中 从雷克雅未克年龄研究的3500名老年人中，我们将开发一种特定于对象的跌倒风险工具 评估从基线数据跌落的可能性，包括年龄、性别、跌倒病史、神经肌肉功能、 动态平衡、视力和药物使用在随访时预测跌倒的发生(目标1)。此外，在 一项对698例病例和2792例对照的前瞻性病例队列研究 测试一种生物力学方法，该方法比较受试者在手术过程中施加于髋部的特定作用力 侧向跌倒至股骨力量，并说明特定受试者跌倒的可能性可改善髋部骨折 预测超出当前临床标准(目标2)。这个项目将产生很大的影响，因为结果将是 有助于更好地了解跌倒风险、冲击负荷和股骨力量对髋关节的影响 骨折，这是必要的，以使设计的干预措施，可能是有效的跌倒预防和 从而减轻髋部骨折的负担。

Project Summary Hip fractures remain one of the most devastating and costly clinical problem affecting older adults. Each year over 300,000 older people sustain hip fracture in the U.S., up to 25% of hip fracture patients die within a year of their injury, and hip fractures account for ~72% of the overall $17 billion cost for osteoporotic fractures. The current clinical standard for assessment of fracture risk is bone mineral density (BMD) testing by dual-energy x-ray absorptiometry (DXA) combined with clinical risk factors. However, half of all fractures occur in those who do not have osteoporosis by BMD testing and/or who have few clinical risk factors, and thus do not meet the WHO fracture risk assessment tool (FRAX) intervention thresholds. Despite the fact that >90% all hip fractures are due to a fall, the current approaches of hip fracture risk do not directly include the probability of falling or the skeletal loading that likely occurs during fall. Our overall goal is to improve the prediction of hip fracture risk by using a biomechanical framework that accounts for the risk of falling, the impact loading due to a fall and femoral strength. In a prospective case-cohort study of 3500 older adults from the AGES Reykjavik study we will develop a subject-specific fall risk tool to evaluate the probability of falling from baseline data including age, sex, fall history, neuromuscular function, dynamic balance, vision and medication use to predict fall occurrence at follow-up (Aim 1). Furthermore, in a prospective case-cohort study of 698 cases and 2792 controls from the AGES-Reykjavik cohort we will test whether a biomechanical approach that compares subject-specific forces applied to the hip during a sideways fall to femoral strength and accounts for subject-specific probability of falling improves hip fracture prediction beyond the current clinical standard (Aim 2). This project will have high impact, as the results will lead to better understanding of the contribution of fall risk, impact loading and femoral strength to hip fracture, that is needed to enable the design of interventions that might be effective in fall prevention and thus, reduce the burden of hip fractures.