Related Experiment Video
Updated: May 5, 2026
Longitudinal Micro-Computed Tomography Image Analysis for User-Defined Region of Interest in Critical-Sized Bone Defects
Published on: June 24, 2025
Combining micro computed tomography and three-dimensional registration to evaluate local strains in shape memory
Therese Bormann1, Georg Schulz2, Hans Deyhle2
1Biomaterials Science Center, University of Basel, c/o University Hospital Basel, 4031 Basel, Switzerland; Institute for Medical and Analytical Technologies, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, 4032 Muttenz, Switzerland.
This study experimentally determined strains in porous NiTi scaffolds under compression. Results reveal local strains up to 15% and validate finite element modeling for implant design.
Area of Science:
- Biomaterials Engineering
- Mechanical Engineering
- Medical Imaging
Background:
- Osseointegration of load-bearing implants is enhanced by mechanical stimulation of bony tissue.
- Porous implants subjected to uniaxial compression experience local tensile and compressive strains.
- Understanding these strain fields is crucial for optimizing implant design and performance.
Purpose of the Study:
- To experimentally determine local displacement and strain fields within porous nickel-titanium (NiTi) scaffolds under uniaxial compression.
- To validate finite element method (FEM) modeling of scaffold behavior.
- To investigate the influence of physiological temperature changes on scaffold properties and phase transitions.
Main Methods:
- Fabrication of open-porous NiTi scaffolds using selective laser melting.
- In-situ synchrotron radiation-based micro computed tomography (SRμCT) during uniaxial compression and temperature increase.
- Non-rigid three-dimensional data registration for analyzing displacement and strain fields.
- Finite element method (FEM) for computational modeling and validation.
Main Results:
- Uniaxial compression of 6% induced local compressive and tensile strains reaching up to 15%.
- Experimental results validated the accuracy of the FEM models used.
- Phase transition from martensite to austenite was observed and localized within the scaffold as temperature increased from 15°C to 37°C, starting around 24°C and finishing around 34°C.
Conclusions:
- The study provides critical data for optimizing the architecture of porous metallic implants.
- Results enable estimation of critical displacements for crack initiation, informing safety margins.
- Optimized mechanical stimuli for porous load-bearing implants can be determined within the physiological temperature range.
