Stochastic Interdigitation as a Toughening Mechanism at the Interface between Tendon and Bone
Stochastic Interdigitation as a Toughening Mechanism at the Interface between Tendon and Bone
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DOI：
10.1016/j.bpj.2014.09.049
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发表时间：
2015-01-20
影响因子：
3.4
通讯作者：
Genin, Guy M.
中科院分区：
文献类型：
--
作者：
Hu, Yizhong;Birman, Victor;Genin, Guy M.
肌腱与骨骼的重新附着和愈合提出了持续的临床挑战，并且常常导致不良结果，部分原因是使未受伤的肌腱与骨骼附着具有韧性的机制尚不清楚。典型的肌腱到骨手术修复的特征之一是将肌腱直接附着到光滑的骨骼上。然而，天然的肌腱与骨骼的附着呈现出粗糙的矿化界面，可能在肌腱和骨骼之间的应力传递中发挥重要作用。在这项研究中，我们研究了界面粗糙度和指间随机性对双材料界面强度和韧性的影响。推导了粗糙界面处应力放大的闭式线性近似，并将其应用于二维晶胞模型。结果表明，粗糙度可能有助于增加肌腱到骨骼插入部位的韧性，但会牺牲其强度。结果进一步表明，天然的肌腱与骨骼的附着呈现出粗糙度，其韧性的增加超过了强度的损失。更一般地说，我们的结果提出了一条改善手术复位策略和结构工程附件的随机途径。
Reattachment and healing of tendon to bone poses a persistent clinical challenge and often results in poor outcomes, in part because the mechanisms that imbue the uninjured tendon-to-bone attachment with toughness are not known. One feature of typical tendon-to-bone surgical repairs is direct attachment of tendon to smooth bone. The native tendon-to-bone attachment, however, presents a rough mineralized interface that might serve an important role in stress transfer between tendon and bone. In this study, we examined the effects of interfacial roughness and interdigital stochasticity on the strength and toughness of a bimaterial interface. Closed form linear approximations of the amplification of stresses at the rough interface were derived and applied in a two-dimensional unit-cell model. Results demonstrated that roughness may serve to increase the toughness of the tendon-to-bone insertion site at the expense of its strength. Results further suggested that the natural tendon-to-bone attachment presents roughness for which the gain in toughness outweighs the loss in strength. More generally, our results suggest a pathway for stochasticity to improve surgical reattachment strategies and structural engineering attachments.