Hériveaux Yoann, Le Cann Sophie, Immel Katharina, Vennat Elsa, Nguyen Vu-Hieu, Brailovski Vladimir, Karasinski Patrick, Sauer Roger A, Haïat Guillaume
Université Paris-Saclay, CentraleSupélec, ENS Paris-Saclay, CNRS, LMPS - Laboratoire de Mécanique Paris-Saclay, 91190, Gif-sur-Yvette, France.
CNRS, Univ Paris Est Creteil, Univ Gustave Eiffel, UMR 8208, MSME, F-94010, Créteil, France.
J Mech Behav Biomed Mater. 2023 May;141:105787. doi: 10.1016/j.jmbbm.2023.105787. Epub 2023 Mar 18.
While cementless implants are now widely used clinically, implant debonding still occur and is difficult to anticipate. Assessing the biomechanical strength of the bone-implant interface can help improving the understanding of osseointegration phenomena and thus preventing surgical failures. A dedicated and standardized implant model was considered. The samples were tested using a mode III cleavage device to assess the mechanical strength of the bone-implant interface by combining experimental and numerical approaches. Four rough (Sa = 24.5 μm) osseointegrated coin-shaped implants were left in sheep cortical bone during 15 weeks of healing time. Each sample was experimentally rotated at 0.03°/sec until complete rupture of the interface. The maximum values of the torque were comprised between 0.48 and 0.72 N m, while a significant increase of the normal force from 7-12 N to 31-43 N was observed during the bone-implant interface debonding, suggesting the generation of bone debris at the bone-implant interface. The experimental results were compared to an isogeometric finite element model describing the adhesion and debonding phenomena through a modified Coulomb's law, based on a varying friction coefficient to represent the transition from an unbroken to a broken bone-implant interface. A good agreement was found between numerical and experimental torques, with numerical friction coefficients decreasing from 8.93 to 1.23 during the bone-implant interface rupture, which constitutes a validation of this model to simulate the debonding of an osseointegrated bone-implant interface subjected to torsion.
虽然非骨水泥植入物目前在临床上已广泛使用，但植入物脱粘仍会发生且难以预测。评估骨 - 植入物界面的生物力学强度有助于增进对骨整合现象的理解，从而预防手术失败。研究考虑了一个专门的标准化植入物模型。通过结合实验和数值方法，使用III型断裂装置对样本进行测试，以评估骨 - 植入物界面的机械强度。四个表面粗糙（Sa = 24.5μm）的骨整合硬币形植入物在绵羊皮质骨中留置15周的愈合时间。每个样本以0.03°/秒的速度进行实验性旋转，直至界面完全破裂。扭矩的最大值在0.48至0.72 N·m之间，而在骨 - 植入物界面脱粘过程中，法向力从7 - 12 N显著增加到31 - 43 N，这表明在骨 - 植入物界面产生了骨碎片。将实验结果与一个等几何有限元模型进行比较，该模型通过修正的库仑定律描述粘附和脱粘现象，基于变化的摩擦系数来表示从完整到破裂的骨 - 植入物界面的转变。在数值和实验扭矩之间发现了良好的一致性，在骨 - 植入物界面破裂过程中，数值摩擦系数从8.93降至1.23，这验证了该模型可模拟受扭转的骨整合骨 - 植入物界面的脱粘情况。
