Casha Aaron R, Camilleri Liberato, Manché Alexander, Gatt Ruben, Attard Daphne, Gauci Marilyn, Camilleri-Podesta Marie-Therese, Grima Joseph N
Department of Anatomy, University of Malta, Msida, Malta; Department of Cardiothoracic Surgery, Mater Dei Hospital, Msida, Malta.
Clin Anat. 2015 May;28(4):512-9. doi: 10.1002/ca.22513. Epub 2015 Feb 26.
As ribs adapt to stress like all bones, and the chest behaves as a pressure vessel, the effect of stress on the ribs can be determined by measuring rib height and thickness. Rib height and thickness (depth) were measured using CT scans of seven rib cages from anonymized cadavers. A Finite Element Analysis (FEA) model of a rib cage was constructed using a validated approach and used to calculate intramuscular forces as the vectors of both circumferential and axial chest wall forces at right angles to the ribs. Nonlinear quadratic models were used to relate rib height and rib thickness to rib level, and intercostal muscle force to vector stress. Intercostal muscle force was also related to vector stress using Pearson correlation. For comparison, rib height and thickness were measured on CT scans of children. Rib height increased with rib level, increasing by 13% between the 3rd and 7th rib levels, where the 7th/8th rib was the widest part or "equator" of the rib cage, P < 0.001 (t-test). Rib thickness showed a statistically significant 23% increase between the 3rd and 7th ribs, P = 0.004 (t-test). Intercostal muscle force was significantly related to vector stress, Pearson correlation r = 0.944, P = 0.005. The three nonlinear quadratic models developed all had statistically significant parameter estimates with P < 0.03. External rib morphology, in particular rib height and thickness, can be predicted using statistical mathematical models. Rib height is significantly related to the calculated intercostal muscle force, showing that environmental factors affect external rib morphology.
与所有骨骼一样，肋骨会适应压力，而胸部的作用类似于一个压力容器，因此通过测量肋骨的高度和厚度可以确定压力对肋骨的影响。使用来自匿名尸体的七个胸廓的CT扫描测量肋骨高度和厚度（深度）。采用经过验证的方法构建胸廓的有限元分析（FEA）模型，并用于计算肌肉内力量，将其作为与肋骨成直角的圆周和轴向胸壁力的矢量。使用非线性二次模型将肋骨高度和肋骨厚度与肋骨水平相关联，并将肋间肌力量与矢量应力相关联。肋间肌力量也使用Pearson相关性与矢量应力相关联。为了进行比较，在儿童的CT扫描上测量肋骨高度和厚度。肋骨高度随肋骨水平增加，在第3和第7肋骨水平之间增加13%，其中第7/8肋骨是胸廓最宽的部分或“赤道”，P < 0.001（t检验）。肋骨厚度在第3和第7肋骨之间显示出统计学上显著的23%的增加，P = 0.004（t检验）。肋间肌力量与矢量应力显著相关，Pearson相关性r = 0.944，P = 0.005。所开发的三个非线性二次模型的参数估计均具有统计学显著性，P < 0.03。外部肋骨形态，特别是肋骨高度和厚度，可以使用统计数学模型进行预测。肋骨高度与计算出的肋间肌力量显著相关，表明环境因素会影响外部肋骨形态。
