J Korean Orthop Res Soc.  2001 Oct;4(2):121-129.

Stress Analysis of Laxity and Conformity using Geometry Modeling Program in Total Knee Replacement Arthroplasty

• Lee MK
• Choi K
• Lee TS

Abstract

The wear or deformation of UHMWPE contact surfaces, one of the major causes of the failure in total knee replacement arthroplasty (TKRA), results from the stress concentration. Thus the kinematics of knee implant should be considered. The objective of this study was to investigate the stress distribution and kinematics of UHMWPE in TKRA. Geometry analysis of UHMWPE was performed using FEM program(ABAQUS 5.8, 1998). 3D auto meshing preprocessor, which made it possible to perform rapid geometry modeling, was developed for the generation of computer model including the effect of the nonlinear soft tissue. For the linear analysis, 2 steps of loading conditions (i) 550N axial compression, (ii) 550N axial compression with 150N shear in AP direction were applied. The compression test using Fuji pressure sensitive film was utilized to validate this finite element analysis. Increasing the femoral frontal radius and closing the frontal clearance reduced the maximum contact stress in inverse proportion to the contact area. Increasing the tibial sagittal radius increased the AP laxity but little affected the conformity.

Keyword

Total knee replacement arthroplasty; UHMWPE; Laxity; Conformity; Finite element analysis; 3D auto mesh; Pressure sensitive film

MeSH Terms

Arthroplasty*
Arthroplasty, Replacement, Knee*
Biomechanical Phenomena
Computer Simulation
Finite Element Analysis
Knee
Radius