INFLUENCE OF POST-CAM DESIGN ON STRESSES ON POSTERIOR- STABILIZED TIBIAL POSTS
Resource
CLINICAL ORTHOPAEDICS AND RELATED RESEARCH v.450 pp.150-156
Journal
CLINICAL ORTHOPAEDICS AND RELATED RESEARCH
Journal Volume
v.450
Pages
150-156
Date Issued
2006
Date
2006
Author(s)
HUANG, CHANG-HUNG
LIAU, JIANN-JONG
HUANG, CHUN-HSIUNG
CHENG, CHENG-KUNG
Abstract
Polyethylene wear and fracture at the tibial post of posterior- stabilized knee prostheses are common complications. Analyzing the stresses on various designs of tibial posts should predict the risk of damage. The post-cam of knee prostheses generally are designed either as flat-on -flat or curve-on- curve contact surfaces. We investigated stress on such tibial posts using a finite element method. We applied a 500-N anteroposterior shear force to the knee at neutral contact and 10° tibial internal rotation when the knee was flexed at 60°, 90°, 120°, and 150°. There was more stress during tibial rotation compared with during neutral contact. The greatest increments of maximum von Mises stress and contact stress in the flat-on-flat model were from 20.4 to 46.1 MPa (126.3%) and from 22.2 to 55.7 MPa (151%), respectively, whereas in the curve-on-curve design they were from 20.5 to 22.7 MPa (10.7%) and from 33.0 to 35.4 MPa (7.2%), respectively. Increased stress concentration at the tibial post occurred at increased flexion angles along with axial tibial rotation. The curve- on-curve design reduced stress concentration when the knee sustained an anteroposterior shear force with tibial rotation.
Description
SCI