Premium
Edge‐loading severity as a function of cup lip radius in metal‐on‐metal total hips—A finite element analysis
Author(s) -
Elkins Jacob M.,
Kruger Karen M.,
Pedersen Douglas R.,
Callaghan John J.,
Brown Thomas D.
Publication year - 2012
Publication title -
journal of orthopaedic research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1002/jor.21524
Subject(s) - enhanced data rates for gsm evolution , materials science , subluxation , radius , finite element method , composite material , orthodontics , structural engineering , medicine , engineering , computer science , telecommunications , alternative medicine , computer security , pathology
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. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:169–177, 2012