Peacock M, Liu G, Carey M, Ambrosius W, Turner C H, Hui S, Johnston C C
Indiana University School of Medicine, Indianapolis, USA.
Osteoporos Int. 1998;8(3):231-9. doi: 10.1007/s001980050059.
Bone mass and structure at the proximal femur are important predictors of hip fracture. The aims of this study were to compare in a large sample of elderly men and women the precision of measurements of bone mass and structure at multiple sites at the proximal femur, to examine their interrelationships, to establish their relationships with age and body size, and to examine criteria for defining geometric and architectural variables in bone structure. Women (n = 336) and men (n = 141) over the age of 60 years were studied cross-sectionally. Bone mineral density (BMD) and content (BMC) at the proximal femur were measured in duplicate by dual-energy X-ray absorptiometry (DXA). Shaft and total upper femur (hip) sites in addition to femoral neck, Ward's triangle and trochanter were measured. Structural variables, measured from radiographs and from DXA images, including cortical thickness at calcar femorale, lateral cotex and midfemur, width of the femur and medulla, Singh grade, hip and femoral axis length, femoral head and neck width and the center of mass of the femoral neck. BMD and BMC had high reproducibility and there were significant differences in reproducibility across sites. Among sites, total upper femur and shaft had the highest reproducibility. Duplicate measurements substantially improved reliability of the measurement and are recommended when the value is close to a diagnostic level or when it will be used to establish rates of change. Reproducibility of structural variables was also high except for the lateral cortex, center of mass and Singh grade. Variance due to measurement error did not change with either age or gender. Women were significantly different from men, after controlling for differences in body size, in all variables except Singh grade and medulla width. BMD and BMC were negatively related to age and positively to body size. Structural variables examined in relation to age and body size fell into two categories. The first comprised variables that were not age-related but were body-size-related suggesting that they could be classified as geometric variables. The second comprised variables that were both body-size-related and age-related, suggesting that they could be classified as architectural variables. Using these criteria, calcar and lateral cortex were architectural variables, whereas shaft width, hip and femoral axis length, femoral head and neck width, and center of mass were geometric in both men and women. In women, shaft cortex width and medulla width were age-related, whereas in men they were not. Singh grade showed no consistent pattern with age or body size in women and men.
股骨近端的骨量和结构是髋部骨折的重要预测指标。本研究的目的是在大量老年男性和女性样本中比较股骨近端多个部位骨量和结构测量的精度，研究它们之间的相互关系，确定它们与年龄和体型的关系，并探讨定义骨结构几何和建筑变量的标准。对336名女性和141名60岁以上男性进行了横断面研究。采用双能X线吸收法（DXA）对股骨近端的骨密度（BMD）和骨量（BMC）进行了两次测量。除了股骨颈、Ward三角和转子外，还测量了股骨干和股骨近端（髋部）的全部部位。从X线片和DXA图像测量结构变量，包括股骨距、外侧皮质和股骨干中部的皮质厚度、股骨宽度和髓腔宽度、Singh分级、髋部和股骨轴线长度、股骨头和颈宽度以及股骨颈的质心。BMD和BMC具有高重复性，各部位的重复性存在显著差异。其中，股骨近端全部部位和股骨干的重复性最高。重复测量显著提高了测量的可靠性，当测量值接近诊断水平或用于确定变化率时建议采用。除外侧皮质、质心和Singh分级外，结构变量的重复性也很高。测量误差引起的方差不随年龄或性别而变化。在控制体型差异后，除Singh分级和髓腔宽度外，女性在所有变量上均与男性存在显著差异。BMD和BMC与年龄呈负相关，与体型呈正相关。与年龄和体型相关的结构变量分为两类。第一类包括与年龄无关但与体型有关的变量，表明它们可归类为几何变量。第二类包括与体型和年龄都有关的变量，表明它们可归类为建筑变量。根据这些标准，股骨距和外侧皮质是建筑变量，而股骨干宽度、髋部和股骨轴线长度、股骨头和颈宽度以及质心在男性和女性中都是几何变量。在女性中，股骨干皮质宽度和髓腔宽度与年龄有关，而在男性中则不然。Singh分级在女性和男性中与年龄或体型均无一致模式。
