Trial Review

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The ANZCTR now automatically displays published trial results and simplifies the addition of trial documents such as unpublished protocols and statistical analysis plans.

These enhancements will offer a more comprehensive view of trials, regardless of whether their results are positive, negative, or inconclusive.

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 endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR


Registration number
ACTRN12612000589886
Ethics application status
Not yet submitted
Date submitted
30/05/2012
Date registered
1/06/2012
Date last updated
1/06/2012
Type of registration
Prospectively registered

Titles & IDs
Public title
A study to evaluate the harmful effects of metal ions on eyesight in patients with an ASR total hip replacement.
Scientific title
A study on the ASR metal on metal hip resurfacing: Impact of cobalt toxicity on visual pathways and the presence of soft tissue destruction in the symptomatic hip.
Secondary ID [1] 280588 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Visual acuity and correlation with metal ion levels (Co/Cr) in patients with metal on metal ASR total hip replacements. 286583 0
Condition category
Condition code
Eye 286857 286857 0 0
Diseases / disorders of the eye
Musculoskeletal 286858 286858 0 0
Other muscular and skeletal disorders

Intervention/exposure
Study type
Observational
Patient registry
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
The harmful effects of elevated metal ion levels in the systemic circulation are increasingly being realised. There have been isolated case reports of disturbance of visual pathways as a result of elevated metal ion levels however this has never been investigated in relation to elevated metal ion levels resulting from a hip replacement. The ASR total hip replacement used a metal on metal bearing surface and has now been identified as failing early and in the process result in elevated metal ion levels. This study aims to investigate visual pathways using electrophysiological techniques and then correlate these findings with metal ion levels in a cohort of patients who have undergone an ASR total hip replacement.
The electrophysiological assessments on the eye will take approximately 4 1/2 hours to complete. The metal ion levels will be taken at the point of recruitment and no long term follow up will be part of this study.
Intervention code [1] 284970 0
Not applicable
Comparator / control treatment
Control group will undergone electrophysiological assessment of their visual fields and again correlate these findings with serum metal ion levels. The control group will be made up of patients who have undergone a conventional total hip replacement with a metal on polyethylene bearing surface , hence no concerns over metal ions.
The electrophysiological assessments on the eye will take approximately 4 1/2 hours to complete. The metal ion levels will be taken at the point of recruitment and no long term follow up
Control group
Active

Outcomes
Primary outcome [1] 287216 0
We aim to look at visual acuity by carrying out electrophysiological assessment and correlate these results to serum metal ion levels in order to identify whether serum metal ion levels have any deleterious effect on visual acuity.
Timepoint [1] 287216 0
Patients will be assessed at the point of recruitment and metal ions measured and electrophysiological assessment carried out. This is the only point of assessment on this study as it is beyond the remit of this study to carry out long term follow-up.
Secondary outcome [1] 297647 0
Nil
Timepoint [1] 297647 0
Nil

Eligibility
Key inclusion criteria
Patients recruited will have undergone an ASR total hip replacement or an ASR hip resurfacing.
For the control group patients will have undergone a total hip replacement with a non metal on metal bearing surface (i.e. metal on polyethylene)
Minimum age
No limit
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Not relevant

Study design
Purpose
Screening
Duration
Cross-sectional
Selection
Defined population
Timing
Prospective
Statistical methods / analysis

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
1/01/2013
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
80
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 285343 0
Commercial sector/Industry
Name [1] 285343 0
De Puy
Country [1] 285343 0
Australia
Primary sponsor type
Individual
Name
A/Prof Riaz Khan
Address
Orthopaedic Dept
Sir Charles Gairdner Hospital
Hospital Avenue
Nedlands
Perth
Western Australia
6009
Country
Australia
Secondary sponsor category [1] 284194 0
None
Name [1] 284194 0
Address [1] 284194 0
Country [1] 284194 0

Ethics approval
Ethics application status
Not yet submitted
Ethics committee name [1] 287357 0
Sir Charles Gairder Hospital Ethics Committee
Ethics committee address [1] 287357 0
Hospital Avenue
Nedlands
Perth
Western Australia
6009
Ethics committee country [1] 287357 0
Australia
Date submitted for ethics approval [1] 287357 0
01/07/2012
Approval date [1] 287357 0
Ethics approval number [1] 287357 0

Summary
Brief summary
Total hip replacement is now a well established operation to reliably alleviate pain from osteoarthritis of the hip joint. Over the years a number of bearing surfaces have been used in order to minimise the wear within the joint itself. One such bearing surface is a metal socket articulating with a metal ball. However we know now that although this provides very low wear rates, it can result in metal ions being released into the blood stream as a result of this wear process.

It is the precise effects of these metal ions within the blood stream that we are beginning to understand more about. In particular we know very little about the effect that metal ions have on the eyesight and if metal ion levels are high whether this can cause changes in visual acuity.

This study aims to measure blood levels of Cobalt and Chrome in your blood stream and then potentially carry out specific tests to look at the functioning of the cells within the eyes to assess whether this is abnormal.
Trial website
There will be no trial website. Patients will receive printed information booklets.
Trial related presentations / publications
Nil
Public notes

Contacts
Principal investigator
Name 34242 0
Address 34242 0
Country 34242 0
Phone 34242 0
Fax 34242 0
Email 34242 0
Contact person for public queries
Name 17489 0
A/Prof Riaz Khan
Address 17489 0
Sir Charles Gairdner Hospital
Hospital Avenue
Nedlands
Perth
Western Australia
6009
Country 17489 0
Australia
Phone 17489 0
+61 8 9346 3333
Fax 17489 0
Email 17489 0
[email protected]
Contact person for scientific queries
Name 8417 0
A/Prof Riaz Khan
Address 8417 0
Sir Charles Gairdner Hospital
Hospital Avenue
Nedlands
Perth
Western Australia
6009
Country 8417 0
Australia
Phone 8417 0
+61 8 9346 3333
Fax 8417 0
Email 8417 0
[email protected]

No information has been provided regarding IPD availability


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.