TEMA, Biomechanics Research Group, Department of Mechanical Engineering, University of Aveiro, Campo Universitário de Santiago, Aveiro 3810-193, Portugal.
TEMA, Biomechanics Research Group, Department of Mechanical Engineering, University of Aveiro, Campo Universitário de Santiago, Aveiro 3810-193, Portugal; ESAD- College of Art and Design, Avenida Calouste Gulbenkian, Senhora da Hora, Matosinhos 4460-268, Portugal.
Comput Methods Programs Biomed. 2022 Jun;219:106751. doi: 10.1016/j.cmpb.2022.106751. Epub 2022 Mar 12.
The number of Total Shoulder Arthroplasties (TSA) has increased in these last years with significant increase of clinical success. However, glenoid component loosening remains the most common cause of failure.
In this study we evaluated the critical conditions to predict short and medium-term performance of the uncemented anatomical Comprehensive® Total Shoulder System using a finite element model that was validated experimentally.
The finite element models of an implanted shoulder analysed included total shoulder components with pegs. The models were simulated in 3 phases of adduction: 45°, 60° and 90° to determine the most critical situation. Two different bone-implant fixation conditions were considered: post-surgery and medium term (2 years).
These show that the critical condition is for the shoulder in 90° adduction were the highest contact stress (70 MPa) was observed in the glenoid component. Relatively to the interface implant-bone strains, the maximum (-16000 µε) was observed for the short-term in the lateral region of the humerus. The highest micromotions were observed in the central fixation post of the glenoid component, ranging from 20 to 25 µm, and 325 µm in the lateral plane of the humeral component.
The predicted results are in accordance with clinical studies published and micromotions of the humeral component can be used to predict loosening and to differentiate shoulder implant designs.
近年来，全肩关节置换术（TSA）的数量有所增加，临床成功率显著提高。然而，肩胛盂假体松动仍然是失败的最常见原因。
本研究通过实验验证的有限元模型，评估了预测非骨水泥解剖式 Comprehensive®全肩关节系统短期和中期性能的关键条件。
分析了植入肩部的有限元模型包括带钉的全肩关节组件。模型在 45°、60°和 90°的内收三个阶段进行模拟，以确定最关键的情况。考虑了两种不同的骨-植入物固定条件：术后和中期（2 年）。
结果表明，在 90°内收的肩部情况下，肩胛盂组件的接触应力（70 MPa）最高，为临界条件。关于界面植入物-骨应变，在短期情况下，肱骨外侧区域观察到最大的（-16000 µε）应变。在肩胛盂组件的中央固定钉中观察到最高的微动，范围在 20 到 25 µm 之间，在肱骨组件的横向平面上为 325 µm。
预测结果与已发表的临床研究一致，肱骨组件的微动可用于预测松动，并区分肩部植入物设计。
