Level of activity changes increases the fatigue life of the porous magnesium scaffold, as observed in dynamic immersion tests, over time
Document Type
Article
Publication Date
1-1-2023
Abstract
In the present study, the effects of human physiological activity levels on the fatigue life of a porous magnesium scaffold have been investigated. First, the dynamic immersion and biomechanical testing are carried out on a porous magnesium scaffold to simulate the physiological conditions. Then, a numerical data analysis and computer simulations predict the implant failure values. A 3D CAD bone scaffold model was used to predict the implant fatigue, based on the micro-tomographic images. This study uses a simulation of solid mechanics and fatigue, based on daily physiological activities, which include walking, running, and climbing stairs, with strains reaching 1000-3500 mu m/mm. The porous magnesium scaffold with a porosity of 41% was put through immersion tests for 24, 48, and 72 h in a typical simulated body fluid. Longer immersion times resulted in increased fatigue, with cycles of failure (Nf) observed to decrease from 4.508 x 10(22) to 2.286 x 10(11) (1.9 x 10(11) fold decrease) after 72 hours of immersion with a loading rate of 1000 mu m/mm. Activities played an essential role in the rate of implant fatigue, such as demonstrated by the 1.1 x 1(05) fold increase in the Nf of walking versus stair climbing at 7.603 x 10(11) versus 6.858 x 1(05), respectively. The dynamic immersion tests could establish data on activity levels when an implant fails over time. This information could provide a basis for more robust future implant designs.
Keywords
Cycles of failure, Dynamic immersion, Fatigue, Porous magnesium scaffold
Divisions
fac_med,ortho
Publication Title
Sustainability
Volume
15
Issue
1
Publisher
MDPI
Publisher Location
ST ALBAN-ANLAGE 66, CH-4052 BASEL, SWITZERLAND