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Trial registered on ANZCTR


Registration number
ACTRN12613000860763
Ethics application status
Approved
Date submitted
31/07/2013
Date registered
5/08/2013
Date last updated
7/08/2013
Type of registration
Retrospectively registered

Titles & IDs
Public title
Does the use of a larger femoral head in total hip replacement increase the amount of wear of the plastic liner or the amount of movement of the acetabular cup?
Scientific title
Radiostereometric analysis of polyethylene wear and acetabular component migration following randomisation to either a large 36 mm or standard 28 mm diameter metal on highly cross-linked polyethylene articulation in primary total hip replacement
Secondary ID [1] 282914 0
None
Universal Trial Number (UTN)
U1111-1146-0821
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Polyethylene wear of the highly cross-linked polyethylene liner of the acetabular component of the total hip replacement prosthesis 289727 0
Migration of the acetabular component of the total hip replacement prosthesis 289728 0
Condition category
Condition code
Musculoskeletal 290056 290056 0 0
Osteoarthritis
Surgery 290125 290125 0 0
Other surgery

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Primary total hip replacement using a 36 mm metal on highly cross-linked polyethylene articulation. This is a surgical procedure where the femoral head is removed and replaced by a metal prosthetic femoral head (which in this situation has a diameter of 36 mm), which is attached to a femoral stem inserted into the femur. The head then articulates with a plastic (highly cross-linked polyethylene) liner in a metal acetabular shell, which is inserted into the acetabulum. The duration of the operation is between about 45 minutes and 4 hours, depending on the complexity of the operation.
During the operation tiny tantalum beads are inserted into the polyethylene liner and periprosthetic bone to enable determination of polyethylene wear and acetabular component migration using a highly sophisticated radiographic technique, namely radiostereometric analysis.
Intervention code [1] 287611 0
Treatment: Devices
Intervention code [2] 287660 0
Treatment: Surgery
Comparator / control treatment
Primary total hip replacement using a 28 mm metal on highly cross-linked polyethylene articulation. This is a surgical procedure where the femoral head is removed and replaced by a metal prosthetic femoral head (which in this situation has a diameter of 28 mm), which is attached to a femoral stem inserted into the femur. The head then articulates with a plastic (highly cross-linked polyethylene) liner in a metal acetabular shell, which is inserted into the acetabulum. The duration of the operation is between about 45 minutes and 4 hours, depending on the complexity of the operation.
During the operation tiny tantalum beads are inserted into the polyethylene liner and periprosthetic bone to enable determination of polyethylene wear and acetabular component migration using a highly sophisticated radiographic technique, namely radiostereometric analysis.
Control group
Active

Outcomes
Primary outcome [1] 290110 0
Mean proximal linear polyethylene wear, as measured by radiostereometric analysis
Timepoint [1] 290110 0
Between 3 months and 2 years following total hip replacement
Secondary outcome [1] 303964 0
Mean proximal linear wear, as measured by radiostereometric analysis
Timepoint [1] 303964 0
Between 3 months and 3, 5, 7 and 10 years following total hip replacement
Secondary outcome [2] 303965 0
Percentage of patients exceeding 0.14 mm of proximal linear polyethylene wear, as measured by radiostereometric analysis
Timepoint [2] 303965 0
Between 3 months and 2 years following total hip replacement
Secondary outcome [3] 303966 0
Mean acetabular component migration, as measured by radiostereometric analysis
Timepoint [3] 303966 0
1, 2, 3, 5, 7 and 10 years following total hip replacement

Eligibility
Key inclusion criteria
1. undergoing primary total hip replacement through posterior approach
2. diagnosis of osteoarthritis
3. walking ability restricted only by hip pathology
Minimum age
65 Years
Maximum age
74 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
1. previous infection
2. abnormal acetabulum
3. abnormal abductor mechanism
4. expected leg length inequality >5 cm
5. neuromuscular disease affecting hip

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
A Registration Form detailing all inclusion and exclusion criteria is completed for every patient who is to undergo primary total hip replacement by one of the collaborating surgeons. All eligible patients are then given a Patient Information Sheet/Consent Form. Consenting patients are then stratified and randomised. An envelope with the allocation of either a 28 or 36 mm diameter articulation is opened intra-operatively, after intra-operative exclusion criteria have been assessed.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
A listing of all possible combinations of allocations in blocks of 2 to 8 was prepared (eg for a block of 4: 28,28,36,36; 36,36,28,28, 36,28,36,28 etc) and each combination was allocated a number. Then a random number generator was used to choose the combination sequence for the block sizes required in each stratum.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Patients are stratified for a number of factors that may affect primary and secondary outcomes (eg age, sex).
Blocked randomisation is then undertaken within strata, with patients being randomised to receive a total hip prosthesis with either a 28 mm or 36 mm articulation.
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
We have based our sample size calculation for the 36 mm articulation on an expected mean proximal linear wear of 0.08 mm between three months and two years, and a maximum acceptable mean proximal linear wear of no more than 0.14 mm between three months and two years. We have chosen to use a significance level of 5% (1-sided) and a power of 90% to calculate our sample size because of the limited amount of current knowledge of the in vivo wear of highly cross-linked polyethylene, especially in the 36 mm articulation.
For a one-sample t-test of equivalence of means, a sample size of 21 is required in each arm of the trial in order to infer that the mean wear from 3 months to two years is no more than 0.14 mm, assuming that the sample mean wear is 0.08 mm, with a standard deviation of 0.09.
The sample size was increased to 27 per arm to allow for attrition due to death and loss to follow-up.

Recruitment
Recruitment status
Active, not recruiting
Date of first participant enrolment
Anticipated
Actual
10/12/2002
Date of last participant enrolment
Anticipated
Actual
22/07/2011
Date of last data collection
Anticipated
Actual
Sample size
Target
56
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
SA
Recruitment hospital [1] 1360 0
The Royal Adelaide Hospital - Adelaide
Recruitment postcode(s) [1] 7219 0
5000 - Adelaide

Funding & Sponsors
Funding source category [1] 287694 0
Government body
Name [1] 287694 0
National Health and Medical Research Council
Country [1] 287694 0
Australia
Funding source category [2] 287709 0
University
Name [2] 287709 0
University of Adelaide
Country [2] 287709 0
Australia
Primary sponsor type
Individual
Name
Prof Donald Howie
Address
Department of Orthopaedics and Trauma
Level 4, Bice Building
Royal Adelaide Hospital
North Tce
Adelaide SA 5000
Country
Australia
Secondary sponsor category [1] 286427 0
Individual
Name [1] 286427 0
Dr Oksana Holubowycz
Address [1] 286427 0
Department of Orthopaedics and Trauma
Level 4, Bice Building
Royal Adelaide Hospital
North Tce
Adelaide SA 5000
Country [1] 286427 0
Australia
Other collaborator category [1] 277542 0
Individual
Name [1] 277542 0
Assoc Prof Solomon
Address [1] 277542 0
Department of Orthopaedics and Trauma
Level 4, Bice Building
Royal Adelaide Hospital
North Tce
Adelaide SA 5000
Country [1] 277542 0
Australia
Other collaborator category [2] 277543 0
Individual
Name [2] 277543 0
Mr Stuart Callary
Address [2] 277543 0
Department of Orthopaedics and Trauma
Level 4, Bice Building
Royal Adelaide Hospital
North Tce
Adelaide SA 5000
Country [2] 277543 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 289654 0
Royal Adelaide Hospital Research Ethics Committee
Ethics committee address [1] 289654 0
Level 3, Hanson Institute
Royal Adelaide Hospital
North Tce
Adelaide SA 5000
Ethics committee country [1] 289654 0
Australia
Date submitted for ethics approval [1] 289654 0
Approval date [1] 289654 0
08/11/2002
Ethics approval number [1] 289654 0
010504c

Summary
Brief summary
This randomised controlled trial aims to determine whether a primary total hip replacement prosthesis with a larger 36 mm diameter metal on highly cross-linked polyethylene articulation is associated with significantly greater polyethylene wear and acetabular component migration. This study utilises radiostereometric analysis, the most sensitive radiographic technique available to measure wear and migration in vivo.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 41794 0
Prof Donald Howie
Address 41794 0
Department of Orthopaedics and Trauma
Level 4, Bice Building
Royal Adelaide Hospital
North Tce
Adelaide SA 5000
Country 41794 0
Australia
Phone 41794 0
+61 8 8222 5563
Fax 41794 0
Email 41794 0
[email protected]
Contact person for public queries
Name 41795 0
Dr Oksana Holubowycz
Address 41795 0
Department of Orthopaedics and Trauma
Level 4, Bice Building
Royal Adelaide Hospital
North Tce
Adelaide SA 5000
Country 41795 0
Australia
Phone 41795 0
+61 8 8222 5760
Fax 41795 0
Email 41795 0
[email protected]
Contact person for scientific queries
Name 41796 0
Dr Oksana Holubowycz
Address 41796 0
Department of Orthopaedics and Trauma
Level 4, Bice Building
Royal Adelaide Hospital
North Tce
Adelaide SA 5000
Country 41796 0
Australia
Phone 41796 0
+61 8 8222 5760
Fax 41796 0
Email 41796 0
[email protected]

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No Supporting Document Provided



Results publications and other study-related documents

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