Level of Activity Changes Increases the Fatigue Life of the Porous Magnesium Scaffold, as Observed in Dynamic Immersion Tests, over Time

• Published in: Sustainability 2023-01, Vol.15 (1), p.823
• Main Authors: Putra, Risky Utama, Basri, Hasan, Prakoso, Akbar Teguh, Chandra, Hendri, Ammarullah, Muhammad Imam, Akbar, Imam, Syahrom, Ardiyansyah, Kamarul, Tunku
• Format: Article
• Language: English
• Subjects: Biomechanics; Biomedical materials; Body fluids; Bone regeneration; Bones; Fatigue; Fatigue life; Fatigue testing machines; Immersion; Implants, Artificial; Load distribution; Loading rate; Magnesium; Materials; Materials fatigue; Materials research; Mathematical models; Physiological effects; Physiology; Porosity; Prosthesis; Scaffolds; Simulation; Software; Solid mechanics; Transplants & implants; Walking
• ISSN: 2071-1050; 2071-1050
• DOI: 10.3390/su15010823

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 µm/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 × 1022 to 2.286 × 1011 (1.9 × 1011 fold decrease) after 72 hours of immersion with a loading rate of 1000 µm/mm. Activities played an essential role in the rate of implant fatigue, such as demonstrated by the 1.1 × 105 fold increase in the Nf of walking versus stair climbing at 7.603 × 1011 versus 6.858 × 105, 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.