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Radiographic assessment of cup migration and wear after hip replacement

Ilchmann, Thomas LU (1997) In Acta Orthopaedica Scandinavica. Supplementum
Abstract (Swedish)
Popular Abstract in Swedish

Metoder behövs att noggrant mäta rörelse och slitage av ledpannan efter operation med konstgjord höftled. EBRA-metoden (Ein Bild Röntgen Analyse) presenterades nyligen som en datoriserad metod att mäta rörelse av ledpannan. I denna studie utvärderades ett antal standardmetoder att mäta rörelse av ledpannan och jämfördes med radiostereometri (RSA), en metod som visats ha en mycket hög noggrannhet. En datarutin för mätning av slitage av ledpannan utvecklades till EBRA-metoden. Av standardmetoderna visade sig Nunns metod vara bäst att mäta rörelse av ledpannan och Livermores bäst att mäta slitage. Mätningar med EBRA var bättre än med standardmetoderna. Felställning av bäckenet tycktes vara den... (More)
Popular Abstract in Swedish

Metoder behövs att noggrant mäta rörelse och slitage av ledpannan efter operation med konstgjord höftled. EBRA-metoden (Ein Bild Röntgen Analyse) presenterades nyligen som en datoriserad metod att mäta rörelse av ledpannan. I denna studie utvärderades ett antal standardmetoder att mäta rörelse av ledpannan och jämfördes med radiostereometri (RSA), en metod som visats ha en mycket hög noggrannhet. En datarutin för mätning av slitage av ledpannan utvecklades till EBRA-metoden. Av standardmetoderna visade sig Nunns metod vara bäst att mäta rörelse av ledpannan och Livermores bäst att mäta slitage. Mätningar med EBRA var bättre än med standardmetoderna. Felställning av bäckenet tycktes vara den huvudsakliga orsaken till fel i mätningarna. Effekten av felställning av bäckenet utvärderades experimentellt. EBRA upptäckte och uteslöt felställda bäckenbilder, mätfelet blev mindre med EBRA än med standardmetoderna. Noggrannheten i inmatningsrutinerna, vid upprepade röntgenundersökningar samt felen vid upprepade mätningar av samma, eller flera, undersökare utvärderades. Med undantag av den digitala inmatningen av data var EBRA bättre än standardmetoderna. Normalvärden för rörelse och slitage av ledpannan erhölls från konstgjorda höfter med lång överlevnad utan röntgenologiska tecken till lossning. Ingen mätmetod upptäckte tecken till någon förändring med tiden av slitagehastighet och rörelse. EBRA påvisade plastisk deformering av några ledpannor men gav ingen ytterligare information på lång sikt.



Nunns metod rekommenderas i klinisk praxis för mätning av rörelse och Livermores metod för slitage. EBRA har högre noggrannhet och bör användas för studier av nya höftimplantat som passerat preklinisk, och gärna också radiostereometrisk, analys. RSA är oöverträffat och rekommenderas för tidig klinisk uppföljning av ett begränsat antal patienter. (Less)
Abstract
Methods are needed for accurate measurement of acetabular cup migration and wear after hip replacement. The EBRA (Ein Bild Röntgen Analyse) method was recently introduced as a computerized method for radiographic assessment of acetabular cup migration.



In this study, various standard methods for measuring migration were evaluated and compared to radiostereometry (RSA), which has proved to be highly accurate. A subroutine for wear measurement was developed and added to the EBRA method.



Of the standard methods, Nunn´s method was the best for migration measurement and Livermore´s the best for wear measurement. Measurements with EBRA were better than the standard methods.



Pelvic tilt... (More)
Methods are needed for accurate measurement of acetabular cup migration and wear after hip replacement. The EBRA (Ein Bild Röntgen Analyse) method was recently introduced as a computerized method for radiographic assessment of acetabular cup migration.



In this study, various standard methods for measuring migration were evaluated and compared to radiostereometry (RSA), which has proved to be highly accurate. A subroutine for wear measurement was developed and added to the EBRA method.



Of the standard methods, Nunn´s method was the best for migration measurement and Livermore´s the best for wear measurement. Measurements with EBRA were better than the standard methods.



Pelvic tilt seemed to be the main source of error in measurements. The effect of pelvic tilt was evaluated experimentally. EBRA detected and excluded tilted radiographs, the errors of measurement beeing smaller with EBRA than with standard methods.



The precision of the input procedure, repeated radiographic examination, the intra- and interobserver errors were assessed. Apart from the digital input of the data, EBRA was better than the standard methods.



Normal values concerning acetabular cup migration and wear was obtained from long-term surviving hip replacements, without radiographic signs of loosening. No method of measurement detected evidence of changes in the wear-rate and in migration over time. EBRA showed cold-flow in some cups, but did not provide additional information in the long-term.



Nunn´s method for migration measurements and Livermore´s method for wear are recommended in clinical practice. EBRA is more accurate and should be used for studies of new implant designs that have passed the preclinical and, preferably, radiostereometric analysis. RSA is unsurpassed and is recommended for early clinical follow-up in a limited number of patients. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Prof Ochsner, Peter, Kantonsspital, Liestal, Switzerland
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Surgery, measurement, assessment, loosening, migration, wear, cup, Hip, arthroplasty, orthopaedics, traumatology, Kirurgi, ortopedi, traumatologi
in
Acta Orthopaedica Scandinavica. Supplementum
pages
26 pages
publisher
BG Unfallklinik, Schnarrenbergstrasse, D-72076 Tübingen, Germany,
defense location
Föreläsningssal 1, University Hospital
defense date
1997-11-20 09:15
external identifiers
  • other:ISRN: LUMEDW/MEOL 1052 (1-28)S
ISSN
0300-8827
language
English
LU publication?
yes
id
52831db9-30b4-40ce-9395-874685040547 (old id 29676)
date added to LUP
2007-06-13 13:42:19
date last changed
2016-09-19 08:44:52
@phdthesis{52831db9-30b4-40ce-9395-874685040547,
  abstract     = {Methods are needed for accurate measurement of acetabular cup migration and wear after hip replacement. The EBRA (Ein Bild Röntgen Analyse) method was recently introduced as a computerized method for radiographic assessment of acetabular cup migration.<br/><br>
<br/><br>
In this study, various standard methods for measuring migration were evaluated and compared to radiostereometry (RSA), which has proved to be highly accurate. A subroutine for wear measurement was developed and added to the EBRA method.<br/><br>
<br/><br>
Of the standard methods, Nunn´s method was the best for migration measurement and Livermore´s the best for wear measurement. Measurements with EBRA were better than the standard methods.<br/><br>
<br/><br>
Pelvic tilt seemed to be the main source of error in measurements. The effect of pelvic tilt was evaluated experimentally. EBRA detected and excluded tilted radiographs, the errors of measurement beeing smaller with EBRA than with standard methods.<br/><br>
<br/><br>
The precision of the input procedure, repeated radiographic examination, the intra- and interobserver errors were assessed. Apart from the digital input of the data, EBRA was better than the standard methods.<br/><br>
<br/><br>
Normal values concerning acetabular cup migration and wear was obtained from long-term surviving hip replacements, without radiographic signs of loosening. No method of measurement detected evidence of changes in the wear-rate and in migration over time. EBRA showed cold-flow in some cups, but did not provide additional information in the long-term.<br/><br>
<br/><br>
Nunn´s method for migration measurements and Livermore´s method for wear are recommended in clinical practice. EBRA is more accurate and should be used for studies of new implant designs that have passed the preclinical and, preferably, radiostereometric analysis. RSA is unsurpassed and is recommended for early clinical follow-up in a limited number of patients.},
  author       = {Ilchmann, Thomas},
  issn         = {0300-8827},
  keyword      = {Surgery,measurement,assessment,loosening,migration,wear,cup,Hip,arthroplasty,orthopaedics,traumatology,Kirurgi,ortopedi,traumatologi},
  language     = {eng},
  pages        = {26},
  publisher    = {BG Unfallklinik, Schnarrenbergstrasse, D-72076 Tübingen, Germany,},
  school       = {Lund University},
  series       = {Acta Orthopaedica Scandinavica. Supplementum },
  title        = {Radiographic assessment of cup migration and wear after hip replacement},
  year         = {1997},
}