Title: Design and prototyping of a novel low stiffness cementless hip stem

Authors: Ibrahim Eldesouky; Hassan El-Hofy

Addresses: Department of Industrial Engineering and Systems Management, Egypt-Japan University of Science and Technology, New Borg Elarab, 21934, Egypt ' Department of Industrial Engineering and Systems Management, Egypt-Japan University of Science and Technology, New Borg Elarab, 21934, Egypt

Abstract: Present biocompatible materials that are suitable for load bearing implants have high stiffness compared to the natural human bone. This mechanical mismatch causes a condition known as stress shielding. The current trend for overcoming this problem is to use porous scaffold instead of solid implants to reduce the implant stiffness. Due to the wide spread of metal additive manufacturing machines, porous orthopaedic implants can be mass produced. In this regard, a porous scaffold is incorporated in the design of a low stiffness hip stem. A 3D finite element analysis is performed to evaluate the performance of the new stem with the patient descending the stairs. The results of the numerical study show that the proposed design improves stress and strain distributions in the proximal region which reduce the stress shielding effect. Finally, a prototype of the proposed design is produced using a 3D printer as proof of concept.

Keywords: 3D printing; additive manufacturing; auxetic scaffold; low stiffness; stress shielding.

DOI: 10.1504/IJBET.2020.106033

International Journal of Biomedical Engineering and Technology, 2020 Vol.32 No.3, pp.229 - 244

Received: 03 Mar 2017
Accepted: 04 Jun 2017
Published online: 26 Mar 2020 *

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