Edge-loading severity as a function of cup lip radius in metal-on-metal total hips--a finite element analysis. J Orthop Res 2012 Feb;30(2):169-77
Date
08/04/2011Pubmed ID
21812025Pubmed Central ID
PMC5160130DOI
10.1002/jor.21524Scopus ID
2-s2.0-83855162881 (requires institutional sign-in at Scopus site) 35 CitationsAbstract
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.
Author List
Elkins JM, Kruger KM, Pedersen DR, Callaghan JJ, Brown TDAuthor
Karen Kruger PhD Research Assistant Professor in the MU-MCW Department of Biomedical Engineering department at Marquette UniversityMESH terms used to index this publication - Major topics in bold
Arthroplasty, Replacement, HipFinite Element Analysis
Hip Joint
Humans
Metals
Range of Motion, Articular
Stress, Mechanical