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

This study has been completed.
Information provided by (Responsible Party):
Hussain Kazi, Wirral University Teaching Hospital NHS Trust Identifier:
First received: September 16, 2011
Last updated: April 27, 2016
Last verified: April 2016
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.

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

Resource links provided by NLM:

Further study details as provided by Wirral University Teaching Hospital NHS Trust:

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

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

Enrollment: 83
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

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.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
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
  Contacts and Locations
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Please refer to this study by its identifier: NCT01437124

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

Responsible Party: Hussain Kazi, Specialist Registrar, Trauma and Orthopaedics, Wirral University Teaching Hospital NHS Trust Identifier: NCT01437124     History of Changes
Other Study ID Numbers: 960558216
Study First Received: September 16, 2011
Results First Received: April 27, 2016
Last Updated: April 27, 2016

Additional relevant MeSH terms:
Arthritis, Rheumatoid
Hip Dislocation, Congenital
Joint Diseases
Musculoskeletal Diseases
Rheumatic Diseases
Connective Tissue Diseases
Autoimmune Diseases
Immune System Diseases
Pathologic Processes
Musculoskeletal Abnormalities
Congenital Abnormalities processed this record on April 21, 2017