Finite Element Analysis of Knee Implant Materials Under Cyclic Loading Condition: An Analysis of Failures

Abstract

Objectives

This study aims to evaluate the mechanical performance of knee implant materials under cyclic loading conditions using Finite Element Methods (FEM). The analysis focuses on three commonly used femoral and tibial component materials: Co-Cr-Mo alloy, Stainless Steel (ISO 5832-1), and Titanium alloy (ISO 5832-2). A plastic cushion of ultra-high molecular weight polyethylene (UHMWPE) is used consistently across all material combinations. The goal is to determine the optimal material for minimizing stress and deformation under n number (millions) of cyclic loading conditions.

Methods

Finite element analysis (FEA) was conducted using ABAQUS to simulate the mechanical performance of the knee implant materials under cyclic loading conditions. The applied loading conditions varied from 700 N to 3500 N, corresponding to the vertical ground reaction and gait cycle forces. The three metallic materials were analysed with UHMWPE to assess contact pressure distribution and wear of PE component after n numbers of cycles.

Results

The analysis showed that Co-Cr-Mo alloy exhibited the least stress 13 MPa and deformation 0.17 mm among the three materials. Paired with PE, it has the least contact pressure, 0.8 MPa, and the wear rate of PE is 0.116 mm/million cycles. Titanium alloy and Stainless Steel (ISO 5832-1) showed higher stress and deformation, indicating lower durability under cyclic loading.

Conclusion

These findings highlight Co-Cr-Mo alloy as the optimal material for knee implants, enhancing mechanical stability and longevity. This selection minimizes failure rates and revision surgeries.

Future work includes experimental validation and advanced modelling to refine computational findings and develop patient-specific implants.