Voycheck Carrie A, Luu Kelvin, McMahon Patrick J, Debski Richard E
Department of Bioengineering, Musculoskeletal Research Center, Swanson School of Engineering, University of Pittsburgh, 408 Center for Bioengineering, 300 Technology Drive, Pittsburgh, PA, 15219, USA.
Biomech Model Mechanobiol. 2014 Apr;13(2):379-85. doi: 10.1007/s10237-013-0503-2. Epub 2013 Jun 1.
The glenohumeral joint is frequently dislocated resulting in injury to the glenohumeral capsule. Repair techniques that focus on restoring the capsule after dislocation to re-establish its stabilizing function could benefit from predictions of the location of failure in this continuous sheet of tissue with a random collagen fiber alignment in the unloaded state. Therefore, the objective of this study was to determine the collagen fiber alignment and maximum principal strain in all regions of the capsule during uniaxial extension to failure and to determine whether these parameters could predict the location of tissue failure. Collagen fiber alignment, quantified using a small-angle light-scattering device, and maximum principal strain in the capsule were determined at 5% increments of elongation until tissue failure. A contingency table analyzed with Fischer's exact test demonstrated that peak collagen fiber alignment, represented by the normalized orientation index (p < 0.001) and maximum principal strain (p < 0.001), is significant in predicting location of failure. The direct correlation between the maximum principal strain and collagen fiber alignment measured prior to failure to the location of tissue failure suggests these parameters can be used as a predictive tool to help locate the areas of the glenohumeral capsule that are susceptible to failure. In the future, changes in collagen fiber alignment following injury could be used to develop a constitutive model for injured capsular tissue.
肩肱关节经常脱位，导致肩肱关节囊损伤。专注于脱位后修复关节囊以重新建立其稳定功能的修复技术，可能会受益于对这种在未加载状态下胶原纤维随机排列的连续组织片中失效位置的预测。因此，本研究的目的是确定在单轴拉伸至失效过程中关节囊所有区域的胶原纤维排列和最大主应变，并确定这些参数是否能够预测组织失效的位置。使用小角度光散射装置对胶原纤维排列进行量化，并在伸长率以5%的增量增加直至组织失效时，测定关节囊中的最大主应变。用费舍尔精确检验分析的列联表表明，以归一化取向指数表示的峰值胶原纤维排列（p < 0.001）和最大主应变（p < 0.001）在预测失效位置方面具有显著性。在失效前测量的最大主应变与胶原纤维排列和组织失效位置之间的直接相关性表明，这些参数可作为一种预测工具，以帮助定位肩肱关节囊中易发生失效的区域。未来，损伤后胶原纤维排列的变化可用于建立损伤关节囊组织的本构模型。
