title: The effect of frictional torque and bending moment on corrosion at the taper interface : an in vitro study.
abstract: The aim of this study was to assess the effect of frictional torque and bending moment on fretting corrosion at the taper interface of a modular femoral component and to investigate whether different combinations of material also had an effect. The combinations we examined were 1) cobalt-chromium (CoCr) heads on CoCr stems 2) CoCr heads on titanium alloy (Ti) stems and 3) ceramic heads on CoCr stems. In test 1 increasing torque was imposed by offsetting the stem in the anteroposterior plane in increments of 0 mm, 4 mm, 6 mm and 8 mm when the torque generated was equivalent to 0 Nm, 9 Nm, 14 Nm and 18 Nm. In test 2 we investigated the effect of increasing the bending moment by offsetting the application of axial load from the midline in the mediolateral plane. Increments of offset equivalent to head + 0 mm, head + 7 mm and head + 14 mm were used. Significantly higher currents and amplitudes were seen with increasing torque for all combinations of material. However, Ti stems showed the highest corrosion currents. Increased bending moments associated with using larger offset heads produced more corrosion: Ti stems generally performed worse than CoCr stems. Using ceramic heads did not prevent corrosion, but reduced it significantly in all loading configurations.
authors.affiliation: University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: A
authors.initials: A
authors.lastname: Panagiotidou
authors.affiliation: University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: J
authors.initials: J
authors.lastname: Meswania
authors.affiliation: University College London Hospitals NHS Foundation Trust, 170 Tottenham Court Road, London W1T 7HA, UK.
authors.forename: K
authors.initials: K
authors.lastname: Osman
authors.affiliation: Musgrove Park Hospital, Taunton, Somerset, TA1 5DA, UK.
authors.forename: B
authors.initials: B
authors.lastname: Bolland
authors.affiliation: University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, SO16 6YD, UK.
authors.forename: J
authors.initials: J
authors.lastname: Latham
authors.affiliation: Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex HA7 4LP, UK.
authors.forename: J
authors.initials: J
authors.lastname: Skinner
authors.affiliation: University College London Hospitals, 235 Euston Road, London NW1 2BU, UK.
authors.forename: F S
authors.initials: FS
authors.lastname: Haddad
authors.affiliation: Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex HA7 4LP, UK.
authors.forename: A
authors.initials: A
authors.lastname: Hart
authors.affiliation: University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: G
authors.initials: G
authors.lastname: Blunn
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D001672:Biocompatible Materials; D002516:Ceramics; D002857:Chromium; D003035:Cobalt; D003343:Corrosion; D019544:Equipment Failure Analysis; D005269:Femur / Q000601:surgery; D017276:Friction; D006622:Hip Prosthesis; D006801:Humans; D008422:Materials Testing; D011474:Prosthesis Design; D011475:Prosthesis Failure; D014025:Titanium; D019415:Torque
chemical_list: D001672:Biocompatible Materials; D002857:Chromium; D003035:Cobalt; D014025:Titanium
keywords: Corrosion; Metal on Metal; Taper; Total Hip Replacement; Wear