Design and Analysis of Porous Functionally Graded Femoral Prostheses with Improved Stress Shielding

Abstract

One of the most important problems of total hip replacement is aseptic loosening of the femoral component, which is related to the changes of the stress distribution pattern after implantation of the prosthesis. Stress shielding of the femur is recognized as a primary factor in aseptic loosening of hip replacements. Utilizing different materials is one of the ordinary solutions for that problem, but using functionally graded materials (FGMs) could be better than the conventional solutions. This research work aims at investigating different porous FGM implants and a real femoral bone by a 3D finite element method. The results show that a neutral functionally graded prosthesis cannot extraordinarily make changes in the stress pattern of bone and prosthesis, but an increasing functionally graded prosthesis leads a lower level of stress in the prosthesis, and a decreasing functionally graded prosthesis can properly reduce the stress shielding among these three architectures. Due to the absence of similar results in the specialized literature, this paper is likely to fill a gap in the state-of-the-art bio-implants, and provide pertinent results that are instrumental in the design of porous femoral prostheses under normal walking loading conditions.

Artificial Intelligence Aided Design of Tissue Engineering Scaffolds Employing Virtual Tomography and 3D Convolutional Neural Networks

“…The use of digital tomographies is demonstrated useful for training, validating and testing deep convolutional neural networks, as the employment of images from CT scans had already proven highly useful for the progressive application of AI/ML methods in diagnostic medicine. Although recent studies have also combined machine learning and FEM simulations to predict the mechanical properties of biomaterials lattices and biomechanical structures [ 37 , 38 ], they have normally relied on conventional artificial neural networks (ANNs) with a few parameters as inputs/outputs that describe slight variations in thickness, size, length or density. Moreover, 3D CNNs, loaded with digital slices, receive the whole geometry as input and outperform simpler ANNs, especially when the geometrical complexity increases and when the diversity of geometrical inputs does not allow for a parametrization.…”

Study on mechanical and tribological characteristics of layered functionally graded polymer composite materials

“…However, there is a little work in this context of understanding the modeling of FGMs. But no work or very little work as per the author's knowledge is cited in the literature, such as FEM on porous FGMs to study the enhanced stress shielding properties 51,52 for bone implant surfaces, and functionally graded honeycomb structures for best bending performance using polymers such as Polylactic acid (PLA) and have been validated with FEM analysis. 53 A comparative study on the thermal buckling properties of the shape memory alloys and carbon nano tubes (CNT) based composite laminates were discoursed in detail.…”

Influence of 3D Printing Parameters on the Mechanical Stability of PCL Scaffolds and the Proliferation Behavior of Bone Cells

“…In addition, the procedure requires a second surgery, in which the additional metallic materials (e.g., metal plates to fix the bone defect) are removed after the bone heals because they are not biodegradable. For these reasons, efforts have already been made to either adapt the mechanical properties of the metallic implants to those of the bone by investigating other alloys [ 12 , 13 , 14 ] or, for example, by foaming the material [ 15 ]. Efforts are also underway to replace the metallic materials entirely with other materials, such as polymeric composites [ 16 ] or carbon-fiber-reinforced composites [ 17 , 18 ].…”