Predicting Fragilty Fractures Using Hip Radiographs

描述（申请人提供）：髋部骨折是骨质疏松症最严重的后果。2002年，治疗髋部骨折的费用占全国手术直接支出的63%，即超过100亿美元。到2050年，由于人口迅速老龄化，每年治疗髋部骨折的费用预计将增加6倍，达到600多亿美元。准确估计个体骨质疏松性髋部骨折风险的能力是预防预期髋部骨折增加的关键，因为它可以确定那些需要最有效的骨折复位治疗的个体。骨密度（BMD）测量是目前用于诊断骨质疏松症。然而，它在预测髋部骨折方面的应用有限。这是因为个体骨折风险也受到局部骨结构、骨转换、皮质厚度和跌倒生物力学的强烈影响。我们最近开发了（SBIR一期）无创自动成像技术，使用普通x线片测量皮质和小梁参数，可与3D uCT测量的参数相媲美。一般来说，它包括x射线数字化、感兴趣区域的识别、小梁提取、背景减法以获得小梁结构图像以及这些结构的二化和骨架化。利用算法对小梁结构参数进行了测量。尸体股骨近端核心普通x线片上的二维小梁结构测量值与三维mu/CT测量值具有良好的相关性。这些二维测量也与应用于这些核心以及整个尸体股骨近端的生物力学失效载荷相关（J Bone Min Res 2003;18 supl 2, Abst # 1218, J Bone Min Res; 18 supl 2 Abst # 107 2003）。我们在这项提议中的假设是：与骨密度测量相比，髋骨x光片中有针对性的、局部的骨结构评估大大提高了预测骨质疏松性骨折的能力。为了评估这一假设的有效性，我们将确定该项目第一阶段开发的技术是否有能力区分健康的绝经后妇女和回顾性经历骨质疏松性骨折的绝经后妇女。我们还将测试基于x射线的骨微观结构和骨几何测量在体内的短期再现性，方法是在同一组中间隔不超过两周进行两次测量，作为个体再现性误差的均方根。

DESCRIPTION (provided by applicant): Hip fracture is the most serious consequence of osteoporosis. In 2002, the cost of treating hip fractures consumed 63% of the national direct expenditure for OP, or more than $10 billion. By 2050, due to a rapidly aging population, the annual cost of treating hip fractures is projected to increase 6 fold to more than $60 billion. The ability to accurately estimate an individual's risk of osteoporotic hip fracture is key in preventing the expected increase of hip fractures because it would identify those individuals needing the most potent available fracture reduction therapy. Bone Mineral Density (BMD) measurement is currently used for diagnosis of osteoporosis. However, it has only limited utility in predicting hip fracture. This is because Individual fracture risk is also strongly influenced by local bone architecture and structure, bone turnover, cortical thickness, and, fall biomechanics. We recently developed (SBIR Phase 1) non-invasive automated imaging technology using ordinary radiographs that can measure cortical and trabecular parameters that are comparable to those measured by 3D uCT. In general it involves x-ray digitization, identification of regions of interest, trabecular extraction, background subtraction to obtain an image of trabecular structures and binerization plus skeletonization of those structures. Parameters of trabecular structure are measured using algorithms. 2D measurements of trabecular structure in ordinary radiographs of cores of proximal cadaveric femora correlated well with 3D mu/CT measurements. Those 2D measurements also correlated with biomechanical failure loads applied to those cores as well to whole cadaver proximal femora(J Bone Min Res 2003 ;18 Suppl 2, Abst # 1218, J Bone Min Res; 18 Suppl 2 Abst # 107 2003.). Our hypotheses in this proposal are: targeted, focal assessment of bone structure in hip x-ravs yields vastly improved ability to predict osteoporotic fracture as compared with BMD measurements. To assess the validity of this hypothesis, we will determine if the technology developed in Phase I of this project has the ability to discriminate between healthy postmenopausal women and postmenopausal women who have retrospectively experienced osteoporotic fractures. We will also test the short term reproducibility in vivo of our x-ray based measurements of bone microstructure and bone geometry by measuring them twice in those same groups no more than two weeks apart as the root mean square of the individual reproducibility errors.