Rantalainen Timo, Weeks Benjamin K, Nogueira Rossana C, Beck Belinda R
Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia.
Menzies Health Institute Queensland, School of Allied Health Sciences, Griffith University, Gold Coast, Australia.
Bone. 2016 Dec;93:71-78. doi: 10.1016/j.bone.2016.09.015. Epub 2016 Sep 17.
Skeletal robustness (cross-section size relative to length) is associated with stress fractures in adults, and appears to explain the high incidence of distal radius fractures in adolescents. However, little is known about the ontogeny of long bone robustness during the first three decades of life. Therefore, we explored the ontogeny of tibial, fibular, ulnar and radial robustness in a cross-sectional sample of 5 to 29year-old volunteers of both sexes. Peripheral quantitative computed tomography (pQCT) was used to evaluate cross-sections of the leg (4%, 14%, 38% and 66%), and forearm (4%, and 66%) in N=432 individuals. Robustness was evaluated as the total bone area divided by bone length. Differences between age-groups, sexes, and age-group×sex interactions were evaluated with ANOVA with Tukey's post hocs where appropriate. Most bone sites exhibited more robust bones in men than women (P<0.001 to 0.02), and in older age-groups than younger (P<0.001). Sex×age-group interaction was observed at the 66% and 38% tibia sites with robustness increasing more with age in men than in women (P=0.006 to 0.042). Post-hoc analyses indicated no sex differences prior to 13years-of-age, and notable exceptions to increasing robustness with age at the 4% radial and 66% tibial sites, which exhibited reduced robustness in age groups close to peak height velocity. In conclusion, the present results suggest that very little sexual dimorphism in long bone robustness exists prior to puberty, and that divergence occurs primarily after cessation of longitudinal growth. A period of relative diaphyseal slenderness was identified at age-groups coinciding with the adolescent growth spurt, which may be related to the relatively high incidence of frank and stress fracture in adolescents.
骨骼粗壮度（横截面大小相对于长度）与成年人应力性骨折相关，且似乎可以解释青少年桡骨远端骨折的高发病率。然而，对于生命最初三十年中长骨粗壮度的个体发生情况却知之甚少。因此，我们在一个包含5至29岁男女志愿者的横断面样本中，探究了胫骨、腓骨、尺骨和桡骨粗壮度的个体发生情况。使用外周定量计算机断层扫描（pQCT）对N = 432名个体的腿部（4%、14%、38%和66%）以及前臂（4%和66%）的横截面进行评估。将粗壮度评估为骨总面积除以骨长度。在适当情况下，使用方差分析（ANOVA）及Tukey事后检验评估年龄组、性别以及年龄组×性别交互作用之间的差异。大多数骨部位男性的骨骼比女性更粗壮（P < 0.001至0.02），且年龄较大组比年龄较小组更粗壮（P < 0.001）。在胫骨66%和38%部位观察到性别×年龄组交互作用，男性骨骼粗壮度随年龄增长的幅度大于女性（P = 0.006至0.042）。事后分析表明，13岁之前不存在性别差异，在桡骨4%和胫骨66%部位，年龄增长与粗壮度增加的关系存在显著例外，在接近身高增长峰值速度的年龄组中，这些部位的粗壮度有所降低。总之，目前的结果表明，青春期前长骨粗壮度的性别二态性非常小，差异主要在纵向生长停止后出现。在与青少年生长突增相吻合的年龄组中，发现了一段骨干相对纤细的时期，这可能与青少年明显骨折和应力性骨折的相对高发病率有关。
