TITLE:
A Contact Model for Establishment of Hip Joint Implant Wear Metrics
AUTHORS:
Mohammad Hodaei, Kambiz Farhang, Nazanin Maani
KEYWORDS:
Contact Mechanics; Roughness; Hip Implant; Wear; Energy Loss; Toxicity
JOURNAL NAME:
Journal of Biomedical Science and Engineering,
Vol.7 No.4,
March
20,
2014
ABSTRACT: Wear is an important issue in hip implants.
Excessive wear can lead to toxicity and other implant associated medical issues
such as patient discomfort and decreased mobility. Since implant wear is the result of contact between surfaces of femoral
head and acetabulum implant, it is important to establish a model that can
address implant surface roughness interaction. A statistical contact model is
developed for the interaction of femoral head and acetabulum implant in which
surface roughness effects are included. The model accounts for the
elastic-plastic interaction of the implant surface roughness. For this purpose
femoral head and acetabulum implants are considered as macroscopically
spherical surfaces containing micron-scale roughness. Approximate equations are
obtained that relate the contact force to the mean surface separation
explicitly. Closed form equations are obtained for hysteretic energy loss in
implant using the approximate equations.