In laboratory tests, the ultra-high molecular weight polyethylene used for the acetabular cups of Charnley hip prostheses has a very low wear rate against steel. In the body radiographic measurements indicate that the polyethylene wears more rapidly. In order to investigate this higher wear rate, the sockets of acetabular cups removed at post-mortem have been examined using optical and electron...

The effect of kinematics, loading and centre of rotation on the wear of an unconstrained total disc replacement have been investigated using the ISO 18192-1 standard test as a baseline. Mean volumetric wear rate and surface morphological effects were reported. Changing the phasing of the flexions to create a low (but finite) amount of crossing path motion at the bearing surfaces resulted in a s...

Introduction. Unicompartmental arthroplasty of the knee in patients with isolated medial osteoarthritis gives good results, but survival is inferior to that of total knee prosthesis. Knees may fail because positioning of the prosthesis has been suboptimal. The aim of this study was to investigate the influence of the tibial slope on the rate of wear of a medial fixed-bearing unicompartmental kn...

Simultaneous measurements of the curves for wear versus distance, wear rate versus distance, and coefficient of friction versus distance were performed in situ to distinguish the transition from severe running-in wear to mild wear. The effects of the initial surface roughness on the severe running-in wear volume were investigated. Disk-on-plate friction and wear tests were carried out with SUS3...

This article aims in exploring the dry sliding wear performances on aluminum (AA7075) metal matrix composites reinforced with molybdenum disulphide which is a solid lubricant using response surface methodology (RSM). Specific Wear Rate (SWR) for AA7075 pure alloy, AA7075+2wt% and AA7075+4wt% were measured according to ASTM G99 standards pin-on-disc apparatus. Design of experiments was selected ...

.................................................................................................................... iv 1. Introduction .................................................................................................................. 1 2. Theory/Methodology for Wear in Prosthetic Implants ................................................ 3 2.1 Wear Mechanisms ..........

BACKGROUND The low wear rates of crosslinked polyethylenes provide the potential to use larger diameters to resist dislocation. However, this requires the use of thinner liners in the acetabular component, with concern that higher contact stresses will increase wear, offsetting the benefits of the crosslinking. QUESTIONS/PURPOSES We asked the following questions: Is the wear of conventional a...

OBJECTIVE This study tested whether the two-body wear of monolithic zirconia and their corresponding enamel antagonists was higher compared to monolithic alloy and veneered zirconia. MATERIALS AND METHODS Cylindrical specimens (N = 36, n = 6) were prepared out of (A) veneered zirconia (VZ), (B) glazed zirconia using a glaze ceramic (GZC), (C) glazed zirconia using a glaze spray (GZS), (D) man...

In this study, the integrated Taguchi-simulated annealing (SA) approach is applied to examine the wear behaviour of silicon nitride (Si3N4)hexagonal boron nitride (hBN). Wear tests for Si3N4-hBN composite versus steel (ASTM 316L) disc were carried out for a dry sliding conditions in a so-called pin-on-disc arrangement. The tests were realized at % volume of hBN 0, 4, 8, 12, 16 in Si3N4 under th...

It is well established that the total protein concentration and albumin-to-globulin ratio influence the wear of ultra-high molecular polyethylene (UHMWPE, "polyethylene") in joint prostheses. A factor on wear not yet studied, but of possible clinical relevance, is protein cleavage. Such cleavage is expected in the presence of an inflammatory response and as a result of wear processes at the art...