Related Experiment Video
Updated: Feb 21, 2026

Imaging of the Microstructural Failure Mechanism in the Human Hip
Published on: September 29, 2023
The effect of malalignment on stresses in polyethylene component of total knee prostheses--a finite element analysis
Jiann Jong Liau1, Cheng Kung Cheng, Chun Hsiung Huang
1Orthopaedic Biomechanics Laboratory, Institute of Biomedical Engineering, National Yang Ming University, No. 155, Sec. 2, Li-Nung St., Shih-Pai, 11221, ROC, Taipei, Taiwan.
Objective:
To investigate the effects of malalignment on stresses in tibial polyethylene component of total knee prostheses.
Design:
A three-dimensional finite element analysis was used to calculate the contact stress and von Mises stress in the tibial polyethylene component subjected to a compressive load, and the malalignment situations were simulated.
Background:
Many biomechanical studies to investigate the stresses in tibial polyethylene component were assumed at the ideal contact alignment. The effect of malalignment on stresses in tibial polyethylene component was not investigated extensively.
Methods:
Three-dimensional finite element models of the tibiofemoral joint of knee prostheses for three different designs were constructed. Three malalignment conditions including the medial translation (0.25, 0.5 and 1.0 mm), internal rotation (1 degree, 3 degree and 5 degree), and varus tilt (1 degree, 3 degree and 5 degree) of the femoral component relative to the tibial component were simulated. A compression load of 3000 N was applied to the tibiofemoral joint at 0 degree of flexion. The maximum contact stress and von Mises stress in the tibial component were compared to investigate the effects of malalignment.
Results:
In comparing with the neutral position, the greatest increase of maximum contact stress were 67.6%, 14.3% and 145.9% and the greatest increase of maximum von Mises stress were 92.5%, 22.7% and 120.6% in maltranslation, internal rotation and varus tilt simulations, respectively.
Conclusion:
The greatest increase of contact stress and von Mises stress was occurred in the high conformity flat-on-flat design of knee prosthesis under the severest malalignment condition. The high conformity curve-on-curve design of knee prosthesis has the minimal risk of polyethylene wear under the malalignment conditions.
Relevance:
This study revealed the importance of malalignment effect on stresses in tibial polyethylene component. Polyethylene wear in surface replacement total knees will be minimal when a high conformity curve-on-curve knee design is used and the rotational line between the femoral and tibial components has the least effect on polyethylene wear but varus/valgus malalignment, even with the best designed prosthesis will still accelerate wear.
More Related Videos
07:33In Vitro Application of a Wireless Sensor in Flexion-Extension Gap Balance of Unicompartmental Knee Arthroplasty
Published on: May 5, 2023
11:28A Coupled Experiment-finite Element Modeling Methodology for Assessing High Strain Rate Mechanical Response of Soft Biomaterials
Published on: May 18, 2015
Related Concept Videos
Bending of Members Made of Several Materials
Hooke's Law determines stress in each material, stating that stress is proportional to strain but varies due to each material's...
Plastic Deformations of Members with a Single Plane of Symmetry
Plastic Deformations
Plastic Deformations
Residual Stresses in Bending
Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity