Keenan Kendra E, Mears Chad S, Skedros John G
Bone and Joint Research Laboratory, George E. Whalen Veteran's Affairs Medical Center, Salt Lake City, Utah.
Department of Orthopaedics, University of Utah, Salt Lake City, Utah, 84132.
Am J Phys Anthropol. 2017 Apr;162(4):657-681. doi: 10.1002/ajpa.23154. Epub 2017 Jan 25.
Histomorphological analyses of bones are used to estimate an individual's chronological age, interpret a bone's load history, and differentiate species. Among various histomorphological characteristics that can influence mechanical properties of cortical bone, secondary osteon (Haversian system) population density and predominant collagen fiber orientation are particularly important. Cross-sectional shape characteristics of secondary osteons (On.Cr = osteon circularity, On.El = osteon ellipticality) are considered helpful in these contexts, but more robust proof is needed. We sought to determine if variations in osteon shape characteristics are sufficient for accurately differentiating species, load-complexity categories, and regional habitual strain-mode distributions (e.g., tension vs. compression regions).
Circularly polarized light images were obtained from 100-micron transverse sections from diaphyses of adult deer calcanei; sheep calcanei, radii, and tibiae; equine calcanei, radii, and third metacarpals (MC3s); chimpanzee femora; and human femora and fibulae. Osteon cross-sectional area (On.Ar), On.Cr, and On.El were quantified indiscriminately and in the contexts of load-complexity and regional strain-mode distributions.
On.Cr and On.El, when examined independently in terms of all data, or mean (nested) data, for each bone, exceeded 80% accuracy in the inter-species comparisons only with respect to distinguishing humans from nonhumans. Correct classification among the nonhuman species was <70%. When On.Cr and On.El were coupled together and with On.Ar in discriminant function analyses (nested and unnested data) there were high misclassifications in all but human vs. nonhuman comparisons.
Frequent misclassifications in nonhuman comparisons might reflect influences of habitual load complexity and/or strain-mode distributions, or other factors not accounted for by these two considerations.
对骨骼进行组织形态学分析可用于估计个体的实足年龄、解读骨骼的负荷历史以及区分物种。在能够影响皮质骨力学性能的各种组织形态学特征中，次级骨单位（哈弗斯系统）的群体密度和主要胶原纤维取向尤为重要。次级骨单位的横截面形状特征（On.Cr = 骨单位圆度，On.El = 骨单位椭圆度）在这些情况下被认为是有帮助的，但还需要更有力的证据。我们试图确定骨单位形状特征的变化是否足以准确区分物种、负荷复杂性类别以及区域习惯性应变模式分布（例如，张力区与压缩区）。
从成年鹿跟骨、绵羊跟骨、桡骨和胫骨、马跟骨、桡骨和第三掌骨（MC3）、黑猩猩股骨以及人类股骨和腓骨的骨干100微米横切片中获取圆偏振光图像。对骨单位横截面积（On.Ar）、On.Cr和On.El进行了不加区分的量化，并在负荷复杂性和区域应变模式分布的背景下进行了量化。
仅在区分人类与非人类的种间比较中，就所有数据或每种骨骼的均值（嵌套）数据单独检查时，On.Cr和On.El的准确率超过80%。非人类物种之间的正确分类率低于70%。在判别函数分析（嵌套和非嵌套数据）中，当On.Cr和On.El与On.Ar结合在一起时，除了人类与非人类的比较外，在所有比较中都存在较高的错误分类。
非人类比较中频繁出现的错误分类可能反映了习惯性负荷复杂性和/或应变模式分布的影响，或者是这两种考虑因素未涵盖的其他因素的影响。
