Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12618001619235
Ethics application status
Approved
Date submitted
20/09/2018
Date registered
2/10/2018
Date last updated
2/10/2018
Type of registration
Retrospectively registered

Titles & IDs
Public title
A Study to Assess Bone Density and Quality Around the Uncemented Acetabular Socket of a Hip Replacement Pre operatively and over 2 years Following Surgery
Scientific title
Use of the iDXA to Evaluate the Change in Bone Mineral Density around 3 types of uncemented acetabular components used in Total Hip Arthroplasty
Secondary ID [1] 296021 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Acetabular Bone Density Study
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Osteoarthritis of the hip joint 309552 0
Condition category
Condition code
Musculoskeletal 308374 308374 0 0
Osteoarthritis

Intervention/exposure
Study type
Observational
Patient registry
True
Target follow-up duration
2
Target follow-up type
Years
Description of intervention(s) / exposure
The intervention being studied prospectively is an uncemented total hip arthroplasty in subjects with hip osteoarthritis. A DXA scanner will be used to evaluate the change in bone mineral density (BMD) around 3 types of uncemented acetabular components used in total hip arthroplasty. The 3 types of acetabular components are as follows, in order of increasing stiffness:
1) The RM Pressfit cup (Mathys) - a monoblock implant made of ultra high molecular weight polyethylene coated with titanium particles. It has a modulus of elasticity very similar to bone.
2) The Trabecular Metal Modular Acetabular cup (Zimmer) - consists of a shell made from Trabecular Metal and can accept a variety of liners. It resembles bone and has a porous structure, facilitating rapid bony ingrowth.
3) The Pinnacle Acetabular Cup (DePuy) - a 180 degree titanium shell, designed to accept a variety of liners.
A DXA scanner is a diagnostic machine that measures bone density and body composition. DXA stands for dual-energy x-ray absorptiometry, and is a well-validated and widely used technique that provides an accurate and precise quantitative assessment of BMD. The rationale behind using a DXA scanner pre and post operatively in this study is as follows. Of all hip arthroplasties performed worldwide each year, a small but significant rate of failure persists in the form of aseptic loosening, predominantly of the acetabular component. There is also the known phenomenon of stress sheilding, or loss of bone density, around uncemented acetabular components, although the long-term effects of this remain unclear. This loss of BMD around orthopaedic implants only becomes apparent on X-ray when significant (about 70%) bone density is lost. Periprosthetic bone loss is an important factor in assessing long-term implant stability and survival. DXA is a proven method of detecting bone loss before it becomes apparent on X-ray. Additionally, recent studies using 3D quantitative computed tomography (qCT) technology have demonstrated periacetabular BMD loss but exposes the subject to a significant radiation dose of 2.5-3.0 milliSiverts (mSv), whereas DXA exposes the subject to approximately 0.009mSv, which is around 1/30th of the radiation of a routine hip X-ray. The hypothesis is that using the DXA scanner to evaluate the bone quality around the acetabular component will indicate whether osteo-integration has occurred before changes are observed on X-ray changes or are demonstrated clinically, and thus may even supercede the the normal X-ray as a method of evaluating the status of a hip replacement.
The staff performing the DXA scan come from a Registered Nurse background, have completed the Australia, New Zealand Bone Mineral Society (ANZBMS) Clinical Bone Densitometry Training Course, and each have a minimum of 4 years experience in using the DXA BMD scanner.
Before the participants enter the study they will be provided with a Participant Information Sheet and Consent Form that explains what their participation in the study will involve including study procedures, potential risks and benefits, who is responsible for costs, compensation for injury during the study, and how the study information will be stored and used.
The participants will undergo a DXA scan throughout the study at the following timepoints:
Pre operatively: Both hips, and spine (contralateral hip and spine are only scanned this once to identify and exclude those with pre-existing osteoarthritis).
Post operatively: Operated hip at 6 weeks, 6 months, 1 year and 2 years post operatively. At the 6 week visit, an additional 2 DXA scans will be performed in order to determine the precision of the DXA scan.
Standard clinical assessments will be performed during the study, and will include a radiograph of the operated hip, and completion of the following questionnaires: Oxford hip, HAAS, WOMAC, and the UCLA activity scale (see secondary outcomes for acronym explanations). These will all take place pre operatively and at the 6 month, 12 month, 1 year and 2 year timepoints (ie. this excludes the 6 week timepoint).
Participants will have individualised appointment dates for the above activities, which will be performed at the local hospital where both the DXA scanner and X-ray departments are located. The participant will be routinely assessed by the surgeon in their rooms located in the same hospital. Once the DXA technician has completed the scan, they will have the participant complete the questionnaires, and report any changes in medications and any adverse events that have occurred since their last visit. Each of these visits should take 20-30 minutes to complete plus the extra time needed for the routine X-ray and surgeon followup assessment.
Each participants involvement in the study will end once the final DXA scan has been completed at the two year timepoint.
Intervention code [1] 312357 0
Diagnosis / Prognosis
Comparator / control treatment
No control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 307353 0
Bone remodelling and stress sheilding following a hip arthroplasty, as assessed using the DXA bone mineral density scanner.
Timepoint [1] 307353 0
At 6 weeks, 6 months, 12 months [primary timepoint] and 2 years [primary timepoint] postoperatively.
Secondary outcome [1] 351562 0
Participant hip pain and function assessed using the Oxford hip questionnaire
Timepoint [1] 351562 0
Up to 7 days preoperatively and postoperatively at the 6 month, 12 month, and 2 year timepoints
Secondary outcome [2] 351563 0
Participants level of function assessed using the High-Activity Arthroplasty Score (HAAS) questionnaire sheet
Timepoint [2] 351563 0
Up to 7 days preoperatively and postoperatively at the 6 month, 12 month and 2 year timepoints
Secondary outcome [3] 351565 0
Pain, stiffness, and physical functioning of the hip joint assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire
Timepoint [3] 351565 0
Up to 7 days preoperatively and postoperatively at the 6 month, 12 month, and 2 year timepoints
Secondary outcome [4] 351569 0
Muscle power and motion, function and pain assessed using the University of California, Los Angeles (UCLA) activity scale
Timepoint [4] 351569 0
Up to 7 days preoperatively and postoperatively at the 6 month, 12 month, and 2 year timepoints

Eligibility
Key inclusion criteria
1. Adult (>50 years) males and females
2.Scheduled to receive one of the uncemented acetabular components as part of a hip arthroplasty
3. Able to provide informed consent
4. In good general health
Minimum age
50 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
1. Neuromuscular or vascular disease in the affected leg
2. Fracture sequelae
3. Previous pelvic osteotomy
4. Previous extensive hip surgery
5. Metabolic bone disease including osteoporosis (T-score >-3.0)
6. Rheumatoid arthritis
7. Postmenopausal women on systemic hormone replacement therapy
8. Long-term treatment with oral corticosteroids and/or bisphosphonates
9. Inability to consent (such as Alzheimers disease)
10. Serious psychiatric disease
11. Disseminated malignant disease and treatment with radiotherapy and chemotherapy
12. Serious systemic disease
13. Inability to complete questionnaires in English
14. Women of childbearing age who are pregnant or who have not had a negative pregnancy test just prior to the examination

Study design
Purpose
Natural history
Duration
Longitudinal
Selection
Defined population
Timing
Prospective
Statistical methods / analysis
A sample size of 100 patients will enable correlations between functional and BMD measures > approximately 0.3 (R-square>10%) to be detected as statistically significant p,0.05 with 80% power. It is anticipated that no less than 60% of the sample will be re-assessed at 5 years and this sample size will enable correlations > about 0.35 to be detected as statistically significant with 80% power. A sample size of 60 means that the 95% confidence interval on the percentage showing stress shielding at five years will be no more than +/- 13% and more likely +/- about 8%.
Standard descriptive statistics will be used to summarise the demographic and clinical features of the subject population. The BMD measures will be summarised as means, medians, ranges and standard deviations. The frequency of stress shielding will be tabled with 95% confidence intervals. BMD and functional measures will be related and also compared to radiograph interpretations and the presence of stress shielding using Pearson's and Spearman's correlation coefficients and ANOVA, as appropriate.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
24/07/2012
Date of last participant enrolment
Anticipated
Actual
3/06/2016
Date of last data collection
Anticipated
Actual
16/06/2018
Sample size
Target
60
Accrual to date
Final
76
Recruitment outside Australia
Country [1] 20828 0
New Zealand
State/province [1] 20828 0
Canterbury

Funding & Sponsors
Funding source category [1] 300611 0
Charities/Societies/Foundations
Name [1] 300611 0
New Zealand Orthopaedic Association (NZOA) Wishbone Trust
Country [1] 300611 0
New Zealand
Primary sponsor type
Individual
Name
Dr Nigel Gilchrist
Address
CGM Research Trust
Burwood Hospital
300 Burwood Road
Burwood
Christchurch 8083
Country
New Zealand
Secondary sponsor category [1] 300117 0
Individual
Name [1] 300117 0
Professor Gary Hooper
Address [1] 300117 0
Leinster Orthopaedic Centre
Leinster Chambers
165 Leinster Road
Strowan
Christchurch 8014
Country [1] 300117 0
New Zealand
Secondary sponsor category [2] 300196 0
Individual
Name [2] 300196 0
Mr Graham Inglis
Address [2] 300196 0
Leinster Orthopaedic Centre
Leinster Chambers
165 Leinster Road
Strowan
Christchurch 8014
Country [2] 300196 0
New Zealand
Secondary sponsor category [3] 300197 0
Individual
Name [3] 300197 0
Mr Rod Maxwell
Address [3] 300197 0
Leinster Orthopaedic Centre
Leinster Chambers
165 Leinster Road
Strowan
Christchurch 8014
Country [3] 300197 0
New Zealand
Secondary sponsor category [4] 300198 0
Individual
Name [4] 300198 0
Professor Christopher Frampton
Address [4] 300198 0
Department of Psychological Medicine
University of Otago, Christchurch
2 Riccarton Avenue
PO Box 4345
Christchurch 8140
Country [4] 300198 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 301398 0
Upper South B Regional Ethics Committee
Ethics committee address [1] 301398 0
C/O Ministry of Health
6 Hazeldean Road
Level 1 Montgomery Watson Building
Addington
Christchurch 8024
Ethics committee country [1] 301398 0
New Zealand
Date submitted for ethics approval [1] 301398 0
01/12/2011
Approval date [1] 301398 0
10/01/2012
Ethics approval number [1] 301398 0
URB/11/12/047

Summary
Brief summary
The primary purpose of this study is to compare the change in bone density around three different cups with varying degrees of elasticity at a minimum of 2 years. A reduction in bone density, known as stress shielding, has been a well-recognised problem with uncemented hip replacement femoral components. This typically results in bone loss and dysfunction at the head of the femur, but less attention has been paid to the preservation of bone in the acetabulum. Uncemented acetabular components often show erosion of the bone around the implant on plain X-rays in the mid-portion of the acetabular cup, which may be due to the rigidity of the outer shell. The outer shell is one of the two components that together form the acetabular cup in a total hip arthroplasty. Our hypothesis was that less rigid cups would be associated with improved bone density and less stress shielding.
Trial website
Trial related presentations / publications
Public notes
Please note that this trial was registered retrospectively, and the last participant was scanned at 22 months postoperatively, rather than at the scheduled 24 months postoperative timepoint.

Contacts
Principal investigator
Name 86870 0
Dr Nigel Gilchrist
Address 86870 0
CGM Research Trust
Burwood Hospital
300 Burwood Road
Burwood
Christchurch 8083
Country 86870 0
New Zealand
Phone 86870 0
+64 3 3377820
Fax 86870 0
+64 3 3377991
Email 86870 0
[email protected]
Contact person for public queries
Name 86871 0
Dr Nigel Gilchrist
Address 86871 0
CGM Research Trust
Burwood Hospital
300 Burwood Road
Burwood
Christchurch 8083
Country 86871 0
New Zealand
Phone 86871 0
+64 3 3377820
Fax 86871 0
+64 3 3377991
Email 86871 0
[email protected]
Contact person for scientific queries
Name 86872 0
Prof Gary Hooper
Address 86872 0
Leinster Orthopaedic Centre
Leinster Chambers
165 Leinster Road
Strowan
Christchurch 8014
Country 86872 0
New Zealand
Phone 86872 0
+64 3 355 3302
Fax 86872 0
+64 3 355 3216
Email 86872 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
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