Su Peng, Wang Sikai, Lai Yuliang, Zhang Qinran, Zhang Leiyu
School of Electromechanical Engineering, Beijing Information Science and Technology University, Beijing 100124, China.
Beijing Key Laboratory of Advanced Manufacturing Technology, Beijing University of Technology, Beijing 100124, China.
Micromachines (Basel). 2022 Jun 11;13(6):932. doi: 10.3390/mi13060932.
The Ilizarov external fixator plays an important role in the correction of complex malformed limbs. Our purpose in this work was to reveal the transmission of adjustable forces between the external fixator and the broken bone, and express the stress distribution at the end of the broken bone during the orthopedic treatment. Firstly, the screw model of the fixator was established and the theoretical relationship between the adjustable force and the stress was obtained. A sheep tibia was taken as a representative research object and its ediTable 3D entity was obtained by CT scanning. Then the mechanical model of the fixator and tibia was built using the ABAQUS software. Correction experiments were performed on the sheep tibia to measure the adjustable/support forces and tensions of the tibia. The measured results were imported to the screw and mechanical model, and the theoretical and simulation values were calculated. The theoretical tensions calculated by the screw model had a similar shape and doubled the value compared with that of the measured results. The transfer efficiency between the two results was improved and kept at about 50% after the initial 2~3 periods. The maximum stress occurring at the surface of the broken bone end was near the Kirschner wire pinhole. The simulation results for the tensions from the mechanical model showed a similar change trend, and the value was slightly higher. A biomechanical model of the Ilizarov external fixator was derived and verified through calculations, simulations and experiments. The change law of the adjustable forces and the tensions existing in the broken sheep tibias is presented herein, and offers a helpful contribution to orthopedic treatment.
伊里扎洛夫外固定器在复杂畸形肢体的矫正中发挥着重要作用。我们这项工作的目的是揭示外固定器与骨折骨之间可调力的传递，并表达骨科治疗过程中骨折骨末端的应力分布。首先，建立了固定器的螺钉模型，得到了可调力与应力之间的理论关系。以绵羊胫骨为代表性研究对象，通过CT扫描获得其可编辑的三维实体。然后使用ABAQUS软件建立了固定器和胫骨的力学模型。对绵羊胫骨进行矫正实验，测量胫骨的可调/支撑力和张力。将测量结果导入螺钉和力学模型，计算理论值和模拟值。由螺钉模型计算得到的理论张力形状相似，与测量结果相比数值翻倍。在最初的2至3个周期后，两者结果之间的传递效率得到提高并保持在约50%。骨折骨末端表面出现的最大应力靠近克氏针针孔。力学模型的张力模拟结果显示出相似的变化趋势，数值略高。通过计算、模拟和实验推导并验证了伊里扎洛夫外固定器的生物力学模型。本文给出了绵羊骨折胫骨中可调力和张力的变化规律，为骨科治疗提供了有益的贡献。
