Parametric study on the interface pullout strength of the vertebral body replacement cage using FEM-based Taguchi...

Area of Science:

• Biomedical Engineering
• Orthopedic Surgery
• Materials Science

Background:

• Vertebral body cage design is critical for spinal fusion and implant fixation.
• Improper design can lead to fixation failure and affect patient outcomes.
• Optimizing cage geometry is essential for robust biomechanical performance.

Purpose of the Study:

• To investigate the effects of various design factors on vertebral body cage interface strength.
• To identify robust design parameters for vertebral body cages using a finite element analysis (FEA) approach.
• To determine optimal spike and cage configurations for both non-fused and fused bone conditions.

Main Methods:

• Development of three-dimensional finite element models (FEM) with nonlinear contact analysis.
• Application of the Taguchi robust design method to evaluate spike design parameters.
• Simulation of pullout strength to assess interface stability under different conditions.

Main Results:

• Without bone fusion, spike row, spike obliquity, and spike height were key factors, with an optimal pyramidal spike design identified.
• With bone fusion, spike row, spike height, and inner diameter were most significant, favoring a conical spike design.
• FEM analyses successfully predicted interface stiffness and validated the efficiency of the FEM-based Taguchi method.

Conclusions:

• The FEM-based Taguchi method provides an efficient approach to optimize spinal implant design variables.
• Specific design configurations were determined to enhance fixation strength in both non-fused and fused vertebral scenarios.
• This research offers valuable insights for the development of more effective vertebral body replacement devices.