IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1 1049-001 Lisboa, Portugal.
IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1 1049-001 Lisboa, Portugal.
Med Eng Phys. 2020 Jul;81:22-29. doi: 10.1016/j.medengphy.2020.04.009. Epub 2020 May 13.
Although the primary stability of joint implants is fundamental for successful osseointegration, little is know about this issue in the context of stemless shoulder implants. Considering 3D finite element models, the purpose of this study was to evaluate the primary stability of five stemless designs, based on the Sidus, SMR, Simpliciti, Eclipse, and Global Icon stemless systems. Three alternative bone quality conditions were considered for cancellous bone. For the Sidus, SMR, and Simpliciti designs, which do not possess a collar that sits on the cortical rim of the humeral resected surface, contact and no contact conditions were considered between the bone surface and the humeral head components. Micromotions at bone-implant interfaces promoting osseointegration were computed as a measure of primary stability for eight load cases consisting of peak in vivo joint loads measured during selected upper limb activities. Under good bone quality conditions, all stemless designs presented micromotions below 150 μm. The Eclipse-based and Global-Icon based designs were the least sensitive to bone quality. Stemless designs presenting a solid collar or contact between the humeral head component and bone provided more stability. Overall, the Eclipse-based and Global Icon-based designs presented the best performance from the primary stability point of view. However, if bone adaptation data available in the literature are considered along with the primary stability data computed here, the Global Icon-based design, as well as other designs, might be considered superior long-term options due to their better compromise between primary stability and impact on bone adaptation.
尽管关节植入物的初始稳定性对于成功的骨整合至关重要，但对于无柄肩部植入物而言，人们对此知之甚少。考虑到 3D 有限元模型，本研究旨在评估基于 Sidus、SMR、Simpliciti、Eclipse 和 Global Icon 无柄系统的五种无柄设计的初始稳定性。对于松质骨，考虑了三种替代的骨质量条件。对于没有位于肱骨切除表面皮质边缘的领圈的 Sidus、SMR 和 Simpliciti 设计，考虑了骨表面与肱骨头组件之间的接触和无接触条件。作为初始稳定性的度量标准，计算了促进骨整合的骨-植入物界面的微动，这是由在选定的上肢活动中测量的峰值体内关节载荷组成的八个载荷情况。在良好的骨质量条件下，所有无柄设计的微动都低于 150 μm。基于 Eclipse 的和基于 Global Icon 的设计对骨质量最不敏感。提供实心领圈或肱骨头组件与骨之间接触的无柄设计提供了更高的稳定性。总体而言，从初始稳定性的角度来看，基于 Eclipse 的和基于 Global Icon 的设计表现最佳。然而，如果考虑到文献中可用的骨适应数据以及此处计算的初始稳定性数据，基于 Global Icon 的设计以及其他设计可能被认为是更好的长期选择，因为它们在初始稳定性和对骨适应的影响之间具有更好的折衷。
