Cheng X G, Nicholson P H, Boonen S, Brys P, Lowet G, Nijs J, Dequeker J
Arthritis and Metabolic Bone Disease Research Unit, University Hospital, Catholic University of Leuven, Belgium.
Bone. 1997 Jul;21(1):113-7. doi: 10.1016/s8756-3282(97)00083-5.
The effect of femoral neck anteversion on bone mineral density (BMD) and geometry as measured by dual energy X-ray absorptiometry (DXA) was assessed using 64 right proximal femora from 36 male and 28 female cadavers. The anteversion angle was measured on computed tomography (CT) images, and DXA measurements were made both in the neutral position (i.e, at 0 degree anteversion, femoral neck axis parallel to the table) and in the simulated anteverted position (i.e., femoral shaft axis parallel to the table, greater and lesser trochanters in contact with the table, and femoral neck free). The mean anteversion angle measured by CT was 19.3 degrees (range 6 degrees-38 degrees). Anteversion was associated with a significant elevation in femoral neck BMD of +2.8% (range -5.3%-(+)9.8%) (p < 0.05), and the femoral neck BMD increased with increasing anteversion (p < 0.01). Trochanteric BMD was less affected by anteversion, with an average increase of only 0.2% (range -5%-5.9%) (p = n.s.) in the anteverted position, but there was a significant positive association between the change in trochanteric BMD and the anteversion angle (p < 0.01). Anteversion produced a mean reduction of -2.4% (range -7.6%-(+)4.3%) (p < 0.001) in apparent femoral neck axis length, while femoral neck width remained generally unaffected. These data confirm that femoral BMD as measured by DXA is affected by femoral anteversion with a lesser magnitude than previously reported. The use of trochanteric BMD may minimize the influence of anteversion. While the mean changes in BMD and neck axis length attributable to anteversion are modest, the considerable interindividual variability in the magnitude of the effects demonstrates that other factors, such as, the complex geometry of femoral neck modifies the effect of anteversion on BMD measurements. The error in BMD introduced femoral anteversion may represent a significant confounding influence in cross-sectional and longitudinal studies. Careful repositioning of the foot and leg is essential in monitoring changes in BMD longitudinally. Knowledge of the effects of femoral anteversion may assist in understanding the relation of femoral BMD and neck axis length to hip fracture.
使用来自36具男性和28具女性尸体的64根右侧股骨近端，评估股骨颈前倾角对通过双能X线吸收法（DXA）测量的骨矿物质密度（BMD）和几何形状的影响。在计算机断层扫描（CT）图像上测量前倾角，并在中立位置（即前倾角为0度，股骨颈轴线与检查台平行）和模拟前倾角位置（即股骨干轴线与检查台平行，大转子和小转子与检查台接触，股骨颈悬空）进行DXA测量。CT测量的平均前倾角为19.3度（范围为6度至38度）。前倾角与股骨颈BMD显著升高2.8%（范围为-5.3%至+9.8%）相关（p<0.05），且股骨颈BMD随前倾角增加而升高（p<0.01）。转子间BMD受前倾角影响较小，在前倾角位置平均仅增加0.2%（范围为-5%至5.9%）（p=无显著性差异），但转子间BMD变化与前倾角之间存在显著正相关（p<0.01）。前倾角使股骨颈表观轴线长度平均减少2.4%（范围为-7.6%至+4.3%）（p<0.001），而股骨颈宽度通常不受影响。这些数据证实，通过DXA测量的股骨BMD受股骨前倾角影响，但其程度小于先前报道。使用转子间BMD可能会最小化前倾角的影响。虽然前倾角导致的BMD和颈轴线长度的平均变化不大，但效应大小的个体间差异很大，这表明其他因素，如股骨颈的复杂几何形状，会改变前倾角对BMD测量的影响。股骨前倾角导致的BMD误差可能在横断面和纵向研究中代表一个显著的混杂影响。在纵向监测BMD变化时，仔细重新摆放脚和腿的位置至关重要。了解股骨前倾角的影响可能有助于理解股骨BMD和颈轴线长度与髋部骨折的关系。
