Metal Ions in Ceramic on Metal Total Hip Arthroplasty (COM)
|Osteoarthritis Avascular Necrosis Rheumatoid Arthritis Developmental Dysplasia of the Hip|
|Study Type:||Observational [Patient Registry]|
|Study Design:||Observational Model: Cohort
Time Perspective: Prospective
|Target Follow-Up Duration:||5 Years|
|Official Title:||Measurement of Metal Ion Levels and Chromosome Abnormalities in Ceramic on Metal Total Hip Arthroplasty in Vivo|
- Cobalt Chromium Levels [ Time Frame: 2 years post THR ]Serum cobalt chromium levels post THR
- Chromosomal Abnormality [ Time Frame: 2 years post THR ]Deviation of karyotype from normal 2 years post THR
|Study Start Date:||October 2011|
|Study Completion Date:||May 2012|
|Primary Completion Date:||May 2012 (Final data collection date for primary outcome measure)|
Ceramic on metal THA
Those who have received a ceramic on metal total hip replacement
PURPOSE & DESIGN:
The investigators are currently following up a cohort of patients all of whom have had a metal on ceramic total hip arthroplasty.
This new bearing couple has been approved for use in the UK for some time and has recently achieved USA FDA approval.
The attraction of this bearing couple is a low rate of wear with reduced complications associated with ceramic on ceramic bearing such as bearing fracture.
Of recent media attention has been the unacceptably high failure of the DePuy ASR metal on metal hip resurfacing. This metal on metal bearing couple has been associated with increased ion levels and chromosome abnormalities in vivo.
In vitro studies and small in vivo studies have revealed much lower wear, particle numbers and ion levels in ceramic on metal studies than in metal on metal bearing surfaces; however there is no large scale evidence that this is the case.
The investigators currently are following up the largest worldwide series of ceramic on metal bearings and clinical results are excellent. It is important however to obtain hard data on metal ion levels in this population firstly to ensure the long term function and health of this cohort but also to provide a barometer for other surgeons who will be using a prosthesis that as yet has little in the way of long term follow up and data on ion levels in a large cohort.
If the ion levels are unacceptably high then the investigators will need to follow these patients closely and offer revision surgery if there are clinical concerns.
For similar reasons it is important to monitor for chromosomal abnormalities.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01437124
|Wirral University Teaching Hospitals NHS Foundation Trust|
|Wirral, Merseyside, United Kingdom, CH49 5PE|
|Study Director:||Fintan A Carroll, MBBS, FRCS||Consultant Orthopaedic Surgeon|
|Principal Investigator:||Hussain A Kazi, MBChB,FRCS||Specialist Registrar, Trauma & Orthopaedics|