Aaron Jean E, Shore Patricia A, Itoda Mizuo, Morrison Rory J M, Hartopp Andrew, Hensor Elizabeth M A, Hordon Lesley D
School of Biomedical Science, Faculty of Biological Sciences, University of Leeds, Leeds, UK.
School of Biomedical Science, Faculty of Biological Sciences, University of Leeds, Leeds, UK.
Bone. 2015 Sep;78:71-80. doi: 10.1016/j.bone.2015.04.009. Epub 2015 Apr 12.
Trabecular bone disconnection is an independent factor in age-related skeletal failure where real termini (ReTm; rare in youth) may cause weakness disproportionate to tissue loss, yet their structural contribution at vulnerable locations remains uncertain. ReTm (previously recorded at the iliac crest) were mapped in "normal" aged vertebral bodies (T11-L5 autopsy; 20 females, 10 males) and corresponding proximal femora (autopsy; 10 females). Results were compared with biomechanically failed femora from orthopaedic subjects aged >58 yr (osteoporosis OP, 10 females; osteoarthritis OA, 10 females). A novel direct 2D/3D histological method was applied to large, thick (300 μm) slices superficially silver-stained to separate ReTm (unstained) from apparent termini (planar artefacts, brown). Light microscope field co-ordinates enabled ReTm mapping and statistical testing relative to i) sex, ii) tissue sector and iii) slicing plane. In men ReTm populations were small and random while in women they were large and sector-specific. In vertebrae they clustered anterior/superior being rare posterior/inferior; in the femoral head they concentrated distal/superior and also near the fovea, being fewer distal/inferior. A distribution polarity was evident with 100% more ReTm observed transversely (i.e., on tensile-related cross struts) than longitudinally (i.e., on compression-related vertical struts). Their numbers rose in OP (BV/TV<14%, microCT) and in OA (BV/TV>14%), remaining polarised and sector-specific in OP only. Comparative experimentation by marrow elution of an OP animal model demonstrated "floating segments" as a possible outcome. Conclusions were supported statistically that trabecular disconnection "hotspots" at vulnerable locations are sex- and sector-specific, mainly transaxial, and subject to disease modulation.
小梁骨断开是与年龄相关的骨骼衰竭的一个独立因素，其中真正的终末（ReTm；在年轻人中罕见）可能导致与组织损失不成比例的虚弱，但它们在易损部位的结构贡献仍不确定。在“正常”老年椎体（T11-L5尸检；20名女性，10名男性）和相应的近端股骨（尸检；10名女性）中绘制了ReTm（先前在髂嵴记录）。将结果与年龄>58岁的骨科受试者的生物力学失效股骨进行比较（骨质疏松症OP，10名女性；骨关节炎OA，10名女性）。一种新颖的直接二维/三维组织学方法应用于大的、厚的（300μm）切片，表面进行银染，以将ReTm（未染色）与明显的终末（平面伪像，棕色）分开。光学显微镜视野坐标能够进行ReTm映射以及相对于i）性别、ii）组织区域和iii）切片平面的统计测试。在男性中，ReTm群体较小且随机，而在女性中则较大且具有区域特异性。在椎骨中，它们聚集在前部/上部，后部/下部罕见；在股骨头中，它们集中在远端/上部以及靠近中央凹的部位，远端/下部较少。明显存在分布极性，横向（即在与拉伸相关的交叉支柱上）观察到的ReTm比纵向（即在与压缩相关的垂直支柱上）多100%。它们的数量在OP（骨体积/组织体积<14%，显微CT）和OA（骨体积/组织体积>14%）中增加，仅在OP中保持极化和区域特异性。对OP动物模型进行骨髓洗脱的对比实验表明“漂浮节段”是一种可能的结果。统计数据支持了以下结论：易损部位的小梁骨断开“热点”具有性别和区域特异性，主要是跨轴的，并且受疾病调节。
