Bone Representation Effects on Carpal Kinematics in Wrist Finite Element Models: A Methodological Comparison

Area of Science:

• Biomechanics
• Computational Modeling
• Orthopedic Surgery

Background:

• Wrist biomechanics are complex and difficult to study experimentally.
• Finite element analysis (FEA) offers a powerful computational alternative for analyzing wrist joint mechanics.
• Understanding carpal kinematics and displacement patterns is crucial for diagnosing and treating wrist injuries.

Purpose of the Study:

• To compare the accuracy of all-cortical versus cortical-trabecular bone representations in wrist FEA.
• To evaluate the impact of different modeling approaches on carpal displacement predictions during simulated activities.
• To provide guidance on selecting appropriate FEA bone modeling strategies for wrist research.

Main Methods:

• Developed two distinct FEA models from the same wrist CT dataset, differing in bone representation (all-cortical vs. cortical-trabecular).
• Model A utilized shell-solid elements, comprehensive soft tissue, and an explicit solver.
• Model B employed tetrahedral elements, simplified bonded contact, and an implicit solver.

Main Results:

• Model A showed minimal displacement differences (<0.5 mm) between bone representation types, validating simplified modeling with explicit solvers and penalty contact.
• Model B, using bonded contact, systematically underpredicted displacements, especially in the radial column.
• Modeling approach significantly influences carpal kinematic predictions.

Conclusions:

• Simplified all-cortical bone representation is a viable option in wrist FEA when combined with appropriate contact algorithms and explicit solvers.
• Researchers can balance model complexity and computational constraints by selecting the right modeling strategy.
• This study offers practical insights for optimizing FEA methodologies in wrist biomechanics research.