title: The effect of cup orientation and coverage on contact mechanics and range of motion of metal-on-metal hip resurfacing arthroplasty.
abstract: Implant malpositioning has been identified as a factor associated with clinical failures of metal-on-metal hip resurfacings (MoMHRs). This study investigated the effect of cup orientation and cup coverage on the contact mechanics (incidence of edge-loading) and range of motion (ROM) of MoMHR. Three generic MoMHRs with differing amounts of cup coverage were considered at various orientations. Contact area and contact pressure at the bearing surface were predicted for each design using finite element (FE) method. The ROM was determined based on the geometry overlap. Edge contact was found at lower angles of inclination (65 degrees) for lower coverage cup designs; however, they also provided the greatest ROM. Conversely, cups with greater coverage did not exhibit edge contact until the cup was more steeply positioned (75 degrees), however ROM was reduced. This study enables both sets of variable to be considered in the design of metal-on-metal bearings in hip.
authors.affiliation: Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, Leeds, UK. I.wang@leeds.ac.uk
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.forename: Sophie
authors.initials: S
authors.lastname: Williams
authors.forename: Itoro
authors.initials: I
authors.lastname: Udofia
authors.forename: Graham
authors.initials: G
authors.lastname: Isaac
authors.forename: John
authors.initials: J
authors.lastname: Fisher
authors.forename: Zhongmin
authors.initials: Z
authors.lastname: Jin
mesh_terms: D000077:Acetabulum / Q000502:physiology* / Q000601:surgery*; D003198:Computer Simulation; D017076:Computer-Aided Design; D019544:Equipment Failure Analysis; D005269:Femur / Q000502:physiology* / Q000601:surgery*; D017276:Friction; D006622:Hip Prosthesis; D008670:Metals / Q000737:chemistry*; D008954:Models, Biological; D011474:Prosthesis Design; D013499:Surface Properties
chemical_list: D008670:Metals