The effect of flash freezing on variability in spinal cord compression behavior

Area of Science:

• Biomechanics
• Biomaterials Science
• Neuroscience

Background:

• Understanding spinal cord injury mechanics requires characterizing spinal cord tissue compression behavior.
• Precise specimen geometry is crucial for mechanical testing, but challenging due to tissue compliance.

Purpose of the Study:

• To assess the impact of flash freezing on spinal cord tissue preparation and mechanical response.
• To quantify the influence of geometric variations on mechanical behavior.

Main Methods:

• Porcine spinal cord white matter specimens were divided into fresh and flash-frozen groups.
• Unconfined compression tests were performed at two strain rates (0.05 s⁻¹ and 5.0 s⁻¹).
• Parametric finite element analyses investigated geometric effects (face angle, cross-section, friction).

Main Results:

• Flash freezing reduced mechanical response variability (p<0.05) and improved geometric consistency.
• Geometric variations (0-10 deg face angle) caused significant underestimation of peak stress.
• Geometric effects on variation and error exceeded those of interface friction.

Conclusions:

• Flash freezing offers advantages for biomechanical studies of spinal cord tissue by reducing variability.
• Accurate specimen geometry is critical for reliable mechanical testing of spinal cord tissue.
• This study provides a foundation for improved spinal cord tissue characterization.