Investigating Contact Models in Clavicle Fixation Plates: A Finite Element Study of Their Impact on Biomechanical...

Area of Science:

• Orthopedic biomechanics
• Finite element analysis
• Implant design

Background:

• Clavicle fractures are common orthopedic injuries requiring plate fixation for stability.
• Biomechanical performance of fixation constructs depends on plate-bone-screw interactions.
• Understanding contact mechanics is crucial for optimizing clavicle fixation.

Purpose of the Study:

• To investigate the effect of different contact formulations on clavicle fixation constructs.
• To analyze structural stiffness, stress distribution, and interfragmentary strain.
• To compare bonded, no-separation, frictionless, and frictional contact models.

Main Methods:

• Developed a 3D finite element model of the clavicle from CT data.
• Applied inferior bending, axial compression, and torsional loading.
• Evaluated four contact formulations: bonded, no-separation, frictionless, and frictional.

Main Results:

• The bonded model showed highest stiffness but also highest stress concentrations.
• Frictional and frictionless models had lower stiffness and higher interfragmentary strain, suggesting secondary healing.
• No-separation models exhibited intermediate stiffness and strain, with high peak plate stress under bending.

Conclusions:

• Contact conditions critically influence the biomechanical behavior of clavicle fixation.
• Physiologically realistic contact models can enhance finite element predictions.
• Optimizing fixation strategies and implant design requires considering these contact mechanics.