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Metal Ions in Ceramic on Metal Total Hip Arthroplasty (COM)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01437124
Recruitment Status : Completed
First Posted : September 20, 2011
Results First Posted : June 6, 2016
Last Update Posted : June 6, 2016
Information provided by (Responsible Party):
Hussain Kazi, Wirral University Teaching Hospital NHS Trust

Brief Summary:
The investigators aim to measure the blood levels of certain metals in a group of patients all of whom have had a ceramic on metal total hip replacement. This new bearing surface (joint) is relatively new and the investigators are currently following up the largest cohort in the world. Clinical results are currently excellent at 2 years in all patients, however the investigators are mindful of the lessons learned from the high failure rate of several designs of metal on metal hip replacements as well as several in vitro reports and one in vivo case report of elevated metal levels in this particular implant. The investigators feel it is important to measure the metal ion levels in our group to ascertain and compare these with reference standards. Once performed the investigators can relate ion levels to function and x ray changes and provide useful longterm data to the patients and the wider medical community as to whether this bearing surface is safe in the long term or whether it's use should be abandoned. This is useful as there are numerous groups implanting this device in the UK and in addition it has just been awarded FDA approval in the USA - its use is likely to flourish.

Condition or disease
Osteoarthritis Avascular Necrosis Rheumatoid Arthritis Developmental Dysplasia of the Hip

Detailed Description:


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.

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Study Type : Observational [Patient Registry]
Actual Enrollment : 83 participants
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
Study Start Date : October 2011
Actual Primary Completion Date : May 2012
Actual Study Completion Date : May 2012

Resource links provided by the National Library of Medicine

Ceramic on metal THA
Those who have received a ceramic on metal total hip replacement

Primary Outcome Measures :
  1. Cobalt Chromium Levels [ Time Frame: 2 years post THR ]
    Serum cobalt chromium levels post THR

Secondary Outcome Measures :
  1. Chromosomal Abnormality [ Time Frame: 2 years post THR ]
    Deviation of karyotype from normal 2 years post THR

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Those who have received a ceramic on metal total hip arthroplasty

Inclusion Criteria:

  • Over 18 years of age
  • Complete history and physical examination
  • Previously performed ceramic on metal total hip replacement
  • An understanding of the purpose of the study and signed consent form

Exclusion Criteria:

  • Hip arthroplasty other than ceramic on metal bearing
  • Mentally infirm / incapacitated
  • Incomplete history or physical examination
  • Unwillingness to participate in the study

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01437124

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United Kingdom
Wirral University Teaching Hospitals NHS Foundation Trust
Wirral, Merseyside, United Kingdom, CH49 5PE
Sponsors and Collaborators
Hussain Kazi
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Study Director: Fintan A Carroll, MBBS, FRCS Consultant Orthopaedic Surgeon
Principal Investigator: Hussain A Kazi, MBChB,FRCS Specialist Registrar, Trauma & Orthopaedics

Additional Information:

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Responsible Party: Hussain Kazi, Specialist Registrar, Trauma and Orthopaedics, Wirral University Teaching Hospital NHS Trust Identifier: NCT01437124    
Other Study ID Numbers: 960558216
First Posted: September 20, 2011    Key Record Dates
Results First Posted: June 6, 2016
Last Update Posted: June 6, 2016
Last Verified: April 2016
Additional relevant MeSH terms:
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Hip Dislocation, Congenital
Musculoskeletal Diseases
Pathologic Processes
Musculoskeletal Abnormalities
Congenital Abnormalities