Prochor Piotr, Sajewicz Eugeniusz
Department of Biocybernetics and Biomedical Engineering, Faculty of Mechanical Engineering, Bialystok University of Technology, Bialystok, Poland.
Proc Inst Mech Eng H. 2018 Mar;232(3):289-298. doi: 10.1177/0954411917751003. Epub 2018 Jan 19.
Nowadays, numerous internal bone remodelling concepts are under development, in order to estimate long-term functionality of implants by evaluating the intensity of stress-shielding effect. This effect is also analysed for the implants for direct skeletal attachment, considered as a better exoprosthesis fixation method than prosthetic sockets. Most of bone remodelling approaches are based on basic concepts, differing with certain assumptions, which may affect the accuracy of the results. This article compares commonly used internal bone remodelling concepts and evaluates the functionality of the proposed Limb Prosthesis Osseointegrated Fixation System for direct skeletal attachment of limb prosthesis in comparison with two currently available implants: the Intraosseous Transcutaneous Amputation Prosthesis and the Osseointegrated Prostheses for the Rehabilitation of Amputees. Three concepts were chosen: without and with lazy zone and with the use of quadratic formula which considers bone overloading. Therefore, three finite element models were created with identical femur implanted with each of analysed implants. The implants were loaded with loads that refer to two stages of gait cycle (heel strike and toe-off). The analysed concepts have given similar results, allowing to assume that each of them can be successfully used to estimate internal bone remodelling around analysed implants for direct skeletal attachment of limb prosthesis. The results also present higher functionality of the proposed implant for direct skeletal attachment of limb prosthesis due to a significant reduction in stress-shielding in the analysed areas around implant in comparison with the Intraosseous Transcutaneous Amputation Prosthesis and the Osseointegrated Prostheses for the Rehabilitation of Amputees. It suggests that the proposed design is a better alternative to the currently used solutions.
如今，许多内部骨重塑概念正在研发中，以便通过评估应力屏蔽效应的强度来估计植入物的长期功能。对于直接骨骼附着的植入物也进行了这种效应的分析，这种植入物被认为是一种比假肢插座更好的外假体固定方法。大多数骨重塑方法基于基本概念，在某些假设上存在差异，这可能会影响结果的准确性。本文比较了常用的内部骨重塑概念，并评估了所提出的肢体假体骨整合固定系统用于肢体假体直接骨骼附着的功能，与两种现有的植入物进行比较：骨内经皮截肢假体和截肢者康复用骨整合假体。选择了三个概念：无惰性区、有惰性区以及使用考虑骨过载的二次公式。因此，创建了三个有限元模型，每个模型中相同的股骨植入了一种分析的植入物。对植入物施加了参考步态周期两个阶段（足跟触地和足尖离地）的载荷。分析的概念给出了相似的结果，可以假设它们中的每一个都可以成功用于估计围绕分析的用于肢体假体直接骨骼附着的植入物的内部骨重塑。结果还表明，与骨内经皮截肢假体和截肢者康复用骨整合假体相比，所提出的用于肢体假体直接骨骼附着的植入物具有更高的功能，因为植入物周围分析区域的应力屏蔽显著降低。这表明所提出的设计是当前使用解决方案的更好替代方案。
