Buente, D, Bryant, M orcid.org/0000-0003-4442-5169, Ward, M et al. (3 more authors) (2017) The taper corrosion pattern observed for one bi-modular stem design is related to geometry-determined taper mechanics. Medical Engineering & Physics, 46. pp. 79-88. ISSN 1350-4533
Abstract
Bi-modular primary hip stems exhibit high revision rates owing to corrosion at the stem-neck taper, and are associated with local adverse tissue reactions. The aim of this study was to relate the wear patterns observed for one bi-modular design to its design-specific stem-neck taper geometry. Wear patterns and initial geometry of the taper junctions were determined for 27 retrieved bi-modular primary hip arthroplasty stems (Rejuvenate, Stryker Orthopaedics) using a tactile coordinate-measuring device. Regions of high-gradient wear patterns were additionally analyzed via optical and electron microscopy. The determined geometry of the taper junction revealed design-related engagement at its opening (angle mismatch), concentrated at the medial and lateral apexes (axes mismatch). A patch of retained topography on the proximal medial neck-piece taper apex was observed, surrounded by regions of high wear. On the patch, a deposit from the opposing female stem taper—containing Ti, Mo, Zr, and O—was observed. High stress concentrations were focused at the taper apexes owing to the specific geometry. A medial canting of the components may have augmented the inhomogeneous stress distributions in vivo. In the regions with high normal loads interfacial slip and consequently fretting was inhibited, which explains the observed pattern of wear.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | (c) 2017, IPEM. Published by Elsevier Ltd. All rights reserved. This is an author produced version of a paper published in Medical Engineering and Physics. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Taper mechanics; Geometrical mismatch; Design; Failure mechanism; Wear pattern; Fretting corrosion |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Mechanical Engineering (Leeds) > Institute of Functional Surfaces (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 17 Jul 2017 16:08 |
Last Modified: | 21 Jun 2018 00:39 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.medengphy.2017.06.003 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:118433 |