Metal Ions in Ceramic on Metal Total Hip Arthroplasty

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.

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Key information

Conditions

Osteoarthritis Arthritis Arthritis, Rheumatoid Autoimmune Diseases Avascular Necrosis Bone Diseases Congenital Abnormalities Congenital, Hereditary, and Neonatal Diseases and Abnormalities Connective Tissue Diseases Developmental Dysplasia of the Hip Hip Dislocation Immune System Diseases Joint Diseases Joint Dislocations Musculoskeletal Abnormalities Musculoskeletal Diseases Necrosis Osteonecrosis Pathologic Processes Pathological Conditions, Signs and Symptoms Rheumatic Diseases Rheumatoid Arthritis Skin and Connective Tissue Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Wirral University Teaching Hospitals NHS Foundation Trust

Metropolitan Borough of Wirral, Merseyside, CH49 5PE, United Kingdom

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Primary outcomes

Cobalt Chromium Levels

Time frame: 2 years post THR

Serum cobalt chromium levels post THR

Secondary outcomes

Chromosomal Abnormality

Time frame: 2 years post THR

Deviation of karyotype from normal 2 years post THR

Sponsors and collaborators

Lead sponsor

Hussain Kazi

Other

Registry information

Official study title

Measurement of Metal Ion Levels and Chromosome Abnormalities in Ceramic on Metal Total Hip Arthroplasty in Vivo

Acronym: COM

Important dates

Study start: 2011
Primary completion: 2012
Study completion: 2012
First posted: Sep 20, 2011
Registry last updated: Jun 6, 2016

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Published trials that share one or more normalized conditions with this study.

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