Topology optimisation for compliant hip implant design and reduced strain shielding
File(s)materials-14-07184-v2.pdf (4.74 MB)
Published version
Author(s)
van Arkel, Richard Jan
Tan, Nathanael
Type
Journal Article
Abstract
Stiff total hip arthroplasty implants can lead to strain shielding, bone loss and complex revision surgery. The aim of this study was to develop topology optimisation techniques for more compliant hip implant design. The Solid Isotropic Material with Penalisation (SIMP) method was adapted, and two hip stems were designed and additive manufactured: (1) a stem based on a stochastic porous structure, and (2) a selectively hollowed approach. Finite element analyses and experimental measurements were conducted to measure stem stiffness and predict the reduction in stress shielding. The selectively hollowed implant increased peri-implanted femur surface strains by up to 25 percentage points compared to a solid implant without compromising predicted strength. Despite the stark differences in design, the experimentally measured stiffness results were near identical for the two optimised stems, with 39% and 40% reductions in the equivalent stiffness for the porous and selectively hollowed implants, respectively, compared to the solid implant. The selectively hollowed implant’s internal structure had a striking resemblance to the trabecular bone structures found in the femur, hinting at intrinsic congruency between nature’s design process and topology optimisation. The developed topology optimisation process enables compliant hip implant design for more natural load transfer, reduced strain shielding and improved implant survivorship.
Date Issued
2021-11-25
Date Acceptance
2021-11-22
Citation
Materials, 2021, 14 (23), pp.1-16
ISSN
1996-1944
Publisher
MDPI
Start Page
1
End Page
16
Journal / Book Title
Materials
Volume
14
Issue
23
Copyright Statement
© 2021 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
License URL
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (EPSRC)
Identifier
https://www.mdpi.com/1996-1944/14/23/7184
Grant Number
EP/S022546/1
EP/R042721/1
Subjects
3d printing
aseptic loosening
biomimicry
bone remodelling
femoral component
internal structures
lattice
stress shielding
total hip replacement
03 Chemical Sciences
09 Engineering
Publication Status
Published
Date Publish Online
2021-11-25