Logo image
Edge-loading severity as a function of cup lip radius in metal-on-metal total hipsuA finite element analysis
Journal article   Open access   Peer reviewed

Edge-loading severity as a function of cup lip radius in metal-on-metal total hipsuA finite element analysis

Jacob M. Elkins, Karen M. Kruger, Douglas R. Pedersen, John J. Callaghan and Thomas D. Brown
Journal of orthopaedic research, Vol.30(2), pp.169-177
02/01/2012
DOI: 10.1002/jor.21524
PMCID: PMC5160130
PMID: 21812025
url
https://doi.org/10.1002/jor.21524View
Published (Version of record) Open Access

Abstract

While favorable tribological properties and allowance for larger femoral head sizes have made metal-on-metal (MoM) bearings an increasingly popular choice for total hip arthroplasty, concerns have mounted regarding adverse reactions to metal wear debris and ions. MoM cups differ from conventional polyethylene cups in terms of edge profile design and reductions from full hemisphericity, suggesting differences in loading at or near the cup edge, especially during subluxation events. Finite element analysis was used to investigate the effects of cup orientation and lip edge curvature on damage propensity for edge or near-edge loading during subluxation. Increased cup lip radius (resulting in reduced articular arc) had a detrimental effect upon subluxation-free hip range of motion and upon dislocation resistance. Contact stresses near the cup edge demonstrated complex relationships between edge radius and cup orientation, with peak stresses being influenced by both variables. The tendency for scraping wear at the egress site demonstrated similarly complex dependencies. These data indicate that acetabular cup design is an important determinant of edge and near-edge loading damage propensity. (C) 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:169177, 2012
Orthopedics Life Sciences & Biomedicine Science & Technology

Details

Metrics

Logo image