Gómez-Benito M J, García-Aznar J M, Kuiper J H, Doblaré M
Group of Structural Mechanics and Materials Modelling, Aragón Institute of Engineering Research (I3A), University of Zaragoza, María de Luna 3, 50008, Zaragoza, Spain.
J Biomech Eng. 2006 Jun;128(3):290-9. doi: 10.1115/1.2187045.
The stiffness of the external fixation highly influences the fracture healing pattern. In this work we study this aspect by means of a finite element model of a simple transverse mid-diaphyseal fracture of an ovine metatarsus fixed with a bilateral external fixator. In order to simulate the regenerative process, a previously developed mechanobiological model of bone fracture healing was implemented in three dimensions. This model is able to simulate tissue differentiation, bone regeneration, and callus growth. A physiological load of 500 N was applied and three different stiffnesses of the external fixator were simulated (2300, 1725, and 1150 N/mm). The interfragmentary strain and load sharing mechanism between bone and the external fixator were compared to those recorded in previous experimental works. The effects of the stiffness on the callus shape and tissue distributions in the fracture site were also analyzed. We predicted that a lower stiffness of the fixator delays fracture healing and causes a larger callus, in correspondence to well-documented clinical observations.
外固定的刚度对骨折愈合模式有很大影响。在这项研究中，我们通过一个用双侧外固定器固定的绵羊跖骨简单中段横形骨折的有限元模型来研究这一方面。为了模拟再生过程，在三维空间中实现了一个先前开发的骨折愈合的力学生物学模型。该模型能够模拟组织分化、骨再生和骨痂生长。施加了500 N的生理载荷，并模拟了外固定器的三种不同刚度（2300、1725和1150 N/mm）。将骨与外固定器之间的骨折间隙应变和载荷分担机制与先前实验研究中记录的结果进行了比较。还分析了刚度对骨折部位骨痂形状和组织分布的影响。与充分记录的临床观察结果一致，我们预测固定器刚度较低会延迟骨折愈合并导致更大的骨痂。
