PAVE Research Group, Department of Archaeology & Anthropology, University of Cambridge, Cambridge, CB2 3DZ, UK.
Am J Phys Anthropol. 2013 Mar;150(3):442-52. doi: 10.1002/ajpa.22218. Epub 2013 Jan 28.
Cross-sectional geometric (CSG) properties of human long bone diaphyses are typically calculated from both periosteal and endosteal contours. Though quantification of both is desirable, periosteal contours alone have provided accurate predictions of CSG properties at the midshaft in previous studies. The relationship between CSG properties calculated from external contours and "true" (endosteal and periosteal) CSG properties, however, has yet to be examined along the whole diaphysis. Cross-sectional computed tomography scans were taken from 21 locations along humeral, femoral, and tibial diaphyses in 20 adults from a late prehistoric central Illinois Valley cemetery. Mechanical properties calculated from images with (a) artificially filled medullary cavities ("solid") and (b) true unaltered cross-sections were compared at each section location using least squares regression. Results indicate that, in this sample, polar second moments of area (J), polar section moduli (Z(p) ), and cross-sectional shape (I(max) /I(min) ) calculated from periosteal contours correspond strongly with those calculated from cross-sections that include the medullary cavity. Correlations are high throughout most of the humeral diaphysis and throughout large portions of femoral and tibial diaphyses (R(2) = 0.855-0.998, all P < 0.001, %SEE ≤ 8.0, %PE ≤ 5.0), the major exception being the proximal quarter of the tibial diaphysis for J and Z(p). The main source of error was identified as variation in %CA. Results reveal that CSG properties quantified from periosteal contours provide comparable results to (and are likely to detect the same differences among individuals as) true CSG properties along large portions of long bone diaphyses.
人体长骨干骺端的横截面几何（CSG）特性通常是通过骨外膜和骨内膜轮廓来计算的。尽管两者的定量都是理想的，但在以前的研究中，仅骨外膜轮廓就能准确预测骨干中段的 CSG 特性。然而，沿骨干全长，从外部轮廓计算出的 CSG 特性与“真实”（骨内膜和骨外膜）CSG 特性之间的关系尚未得到检验。从伊利诺伊河谷晚期史前墓地的 20 名成年人的 21 个肱骨、股骨和胫骨骨干位置采集了横截面计算机断层扫描。使用最小二乘法回归，在每个节段位置比较了使用（a）人工填充骨髓腔的图像（“实心”）和（b）真实未改变的横截面计算出的力学特性。结果表明，在这个样本中，从骨外膜轮廓计算出的极惯性矩（J）、极截面模数（Z(p) ）和横截面形状（I(max) /I(min) ）与包括骨髓腔的横截面计算出的对应特性非常吻合。在肱骨骨干的大部分和股骨和胫骨骨干的大部分（R(2) = 0.855-0.998，所有 P < 0.001，%SEE ≤ 8.0，%PE ≤ 5.0）中相关性很高，主要例外是胫骨骨干近端四分之一的 J 和 Z(p)。主要误差源被确定为 %CA 的变化。结果表明，从骨外膜轮廓定量的 CSG 特性提供了与真实 CSG 特性相当的结果（并且可能会检测到个体之间的相同差异），这在长骨干骺端的大部分位置都是如此。
