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Alumina–alumina artificial hip joints. Part II: Characterisation of the wear debris from in vitro hip joint simulations

Paper ID Volume ID Publish Year Pages File Format Full-Text
13348 851 2002 8 PDF Available
Title
Alumina–alumina artificial hip joints. Part II: Characterisation of the wear debris from in vitro hip joint simulations
Abstract

Until recently it was not possible to reproduce clinically relevant wear rates and wear patterns in in vitro hip joint simulators for alumina ceramic-on-ceramic hip prostheses. The introduction of microseparation of the prosthesis components into in vitro wear simulations produced clinically relevant wear rates and wear patterns for the first time. The aim of this study was to characterise the wear particles generated from standard simulator testing and microseparation simulator testing of hot isostatically pressed (HIPed) and non-HIPed alumina ceramic-on-ceramic hip prostheses, and compare these particles to those generated in vivo.Standard simulation conditions produced wear rates of ≈0.1 mm3 per million cycles for both material types. No change in surface roughness was detected and very few wear features were observed. In contrast, when microseparation was introduced into the wear simulation, wear rates of between 1.24 (HIPed) and 1.74 mm3 per million cycles (non-HIPed) were produced. Surface roughness increased and a wear stripe often observed clinically on retrieved femoral heads was also reproduced. Under standard simulation conditions only nanometre-sized wear particles (2–27.5 nm) were observed by TEM, and it was thought likely that these particles resulted from relief polishing of the alumina ceramic. However, when microseparation of the prosthesis components was introduced into the simulation, a bi-modal distribution of particle sizes was observed. The nanometre-sized particles produced by relief polishing were present (1–35 nm), however, larger micrometre-sized particles were also observed by both transmission electron microscopy (TEM) (0.02–1 μm) and scanning electron microscopy (SEM) (0.05–>10 μm). These larger particles were thought to originate from the wear stripe and were produced by trans-granular fracture of the alumina ceramic.In Part I of this study, alumina ceramic wear particles were isolated from the periprosthetic tissues from around Mittelmeier ceramic-on-ceramic hip prostheses. Characterisation of the particles by TEM and SEM revealed a bi-modal size distribution. SEM analysis revealed particles in the 0.05–3.2 μm size range, and TEM revealed particles in the 5–90 nm size range, indicating that microseparation of the prosthesis components may be a common event in vivo. This study (Part II) has revealed that the introduction of microseparation of the prosthesis components during the swing phase of the wear simulation reproduced clinically relevant wear rates, wear patterns and wear particles in in vitro hip joint simulators.

Keywords
Alumina ceramic; Total hip arthroplasty; Wear debris; In vitro simulation
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Alumina–alumina artificial hip joints. Part II: Characterisation of the wear debris from in vitro hip joint simulations
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Publisher
Database: Elsevier - ScienceDirect
Journal: Biomaterials - Volume 23, Issue 16, August 2002, Pages 3441–3448
Authors
, , , , , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us