Mechanical Engineering Department, University of Bath, United Kingdom.
School of Mechanical and Materials Engineering, University College Dublin, Ireland.
J Med Eng Technol. 2024 Jan;48(1):1-11. doi: 10.1080/03091902.2024.2355319. Epub 2024 Jun 12.
Total ankle arthroplasty is the gold standard surgical treatment for severe ankle arthritis and fracture. However, revision surgeries due to the failure of the ankle implant are a serious concern. Extreme bone density loss due to bone remodelling is one of the main reasons for implant loosening, with aseptic loosening of the talar component being one of the primary reasons for total ankle arthroplasty revisions. This study is aimed at determining the performance and potential causes of failure of the talar component. Herein, we investigated the stress, strain, and bone density changes that take place in the talus bone during the first 6 months of bone remodelling due to the total ankle arthroplasty procedure. Computed tomography scans were used to generate the 3D geometry used in the finite element (FE) model of the Intact and implanted ankle. The Scandinavian Total Ankle Replacement (STAR™) CAD files were generated, and virtual placement within bone models was done following surgical guidelines. The dorsiflexion physiological loading condition was investigated. The cortical region of the talus bone was found to demonstrate the highest values of stress (5.02 MPa). Next, the adaptive bone remodelling theory was used to predict bone density changes over the initial 6-month post-surgery. A significant change in bone density was observed in the talus bone due to bone remodelling. The observed quantitative changes in talus bone density over 6-month period underscore potential implications for implant stability and fracture susceptibility. These findings emphasise the importance of considering such biomechanical factors in ankle implant design and clinical management.
全踝关节置换术是治疗严重踝关节关节炎和骨折的金标准手术方法。然而，由于踝关节植入物失效而进行的翻修手术是一个严重的问题。由于骨重塑导致的骨质极度流失是植入物松动的主要原因之一，距骨组件的无菌性松动是全踝关节置换术翻修的主要原因之一。本研究旨在确定距骨组件的性能和潜在失效原因。在此，我们研究了由于全踝关节置换术过程中骨重塑导致的距骨骨在最初 6 个月内发生的应力、应变和骨密度变化。使用计算机断层扫描 (CT) 扫描生成完整和植入踝关节有限元 (FE) 模型中使用的 3D 几何形状。生成了斯堪的纳维亚全踝关节置换术 (STAR™) CAD 文件，并按照手术指南在骨模型内进行虚拟放置。研究了背屈生理负荷情况。距骨骨的皮质区域表现出最高的应力值（5.02 MPa）。接下来，使用适应性骨重塑理论预测术后最初 6 个月的骨密度变化。由于骨重塑，距骨骨的骨密度发生了显著变化。在 6 个月的观察期内，距骨骨密度的定量变化强调了对植入物稳定性和骨折易感性的潜在影响。这些发现强调了在踝关节植入物设计和临床管理中考虑这些生物力学因素的重要性。
