Mechanical characterization and numerical simulation of polyether-ether-ketone (PEEK) cranial implants

Area of Science:

• Biomaterials Engineering
• Computational Mechanics
• Medical Device Design

Background:

• Cranial implants have advanced significantly in materials, fixation, and structure over the past decade.
• Patient-specific cranial implants are emerging, necessitating robust mechanical characterization and numerical modeling.
• Accurate simulation is crucial for ensuring functionality and facilitating development of customized implants.

Purpose of the Study:

• To perform mechanical characterization and develop numerical models for patient-specific Polyaryletherketone (PEEK) scaffold cranial implants.
• To validate the accuracy of finite element models against experimental data.
• To compare the computational efficiency of detailed versus homogenized models.

Main Methods:

• Experimental mechanical characterization of PEEK scaffold cranial implants at scaffold and whole implant levels.
• Development of detailed finite element models and homogenized solid shell-like models using Asymptotic Expansion Homogenization (AEH) theory.
• Linear elastic finite element analysis validated against displacement control tests.

Main Results:

• Experimental results demonstrated a linear mechanical response of the implants up to failure.
• Numerical models showed excellent agreement with experimental load-displacement responses.
• The homogenized model achieved 90% reduction in degrees of freedom with results comparable to the detailed model.

Conclusions:

• Linear elastic models are suitable for simulating patient-specific PEEK scaffold cranial implants.
• The developed numerical models accurately reproduce experimental findings.
• Homogenized models offer a computationally efficient alternative for designing customized cranial implants.