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Trial registered on ANZCTR


Registration number
ACTRN12611001015932
Ethics application status
Approved
Date submitted
19/09/2011
Date registered
21/09/2011
Date last updated
22/09/2011
Type of registration
Retrospectively registered

Titles & IDs
Public title
Bone mineral density of the distal femur after Total Knee Arthroplasty
Scientific title
A comparison of bone mineral density of the distal femur following Duracon versus Interax total knee replacement in individuals with primary osteoarthrosis of the knee
Secondary ID [1] 263068 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Knee osteoarthritis 270805 0
Osteopenia near knee arthroplasty implant 270833 0
Risk of fractures near knee arthroplasty implant 270834 0
Condition category
Condition code
Musculoskeletal 270998 270998 0 0
Osteoarthritis
Surgery 271014 271014 0 0
Surgical techniques
Musculoskeletal 271015 271015 0 0
Osteoporosis

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The uncemented Duracon femoral implant has porous-coated ingrowth surface and two small fixation pegs designed to penetrate centrally into the most distal part of the medial and lateral femoral condyles. Operative surgery technique (femoral cut by guide, and insertion without cement) is the same as for the Interax prosthesis, and operation time (implant procedure) approximately 1.5 hours, as for the Interax implant. The implant is expected to be in place for at least 10-20 years after primary operation.
NB: The Duracon prosthesis has a metalbacked patella component whereas the Interax prosthesis has a cemented polyethylene patella component.
Intervention code [1] 269420 0
Treatment: Devices
Intervention code [2] 269433 0
Treatment: Surgery
Comparator / control treatment
The Interax femoral implant is hydroxyapatite (HA) coated with a relatively large pore size, cast mesh ingrowth surface and a central anterior placed 20 mm long fixation peg.
Operative surgery technique (femoral cut by guide, and insertion without cement) is the same as for the Duracon prosthesis, and operation time (implant procedure) approximately 1.5 hours, as for the Duracon implant. The implant is expected to be in place for at least 10-20 years after primary operation.
NB: The Duracon prosthesis has a metalbacked patella component whereas the Interax prosthesis has a cemented polyethylene patella component.
Control group
Active

Outcomes
Primary outcome [1] 279661 0
Bone mineral density (BMD) adjacent to the implant.
A Norland XR-46, Norland Corp. Fort Atkinson, Wis DEXA scanner was used.
Timepoint [1] 279661 0
Postoperatively (within 2 weeks), 3, 6 12 and 24 months postoperatively.
Primary outcome [2] 279674 0
Bone mineral concentration (BMC) in the distal tibiae.
A Norland XR-46, Norland Corp. Fort Atkinson, Wis DEXA scanner was used
Timepoint [2] 279674 0
Postoperatively (within 2 weeks), 3, 6 12 and 24 months postoperatively.
Secondary outcome [1] 294152 0
HSS knee society knee score.
Timepoint [1] 294152 0
Preoperatively, 12 and 24 months postoperatively

Eligibility
Key inclusion criteria
Primary osteoarthrosis of the knee
Minimum age
59 Years
Maximum age
90 Years
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
1. Consuming steroid drugs (above 5mg per day).
2. Not able to participate (coorporate) due to bad mental status.

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)
Randomization using sealed opaque envelopes
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Block randomization with 4 patients in each group.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 3851 0
Denmark
State/province [1] 3851 0
Copenhagen

Funding & Sponsors
Funding source category [1] 269893 0
Hospital
Name [1] 269893 0
Rigshospitalet, Copenhagen University Hospital, orthop. dept.
Address [1] 269893 0
Blegdamsvej 3
2100 Copenhagen OE
Country [1] 269893 0
Denmark
Primary sponsor type
Hospital
Name
Rigshospitalet, Copenhagen University Hospital, orthop. dept.
Address
Blegdamsvej 3
2100 Copenhagen OE
Country
Denmark
Secondary sponsor category [1] 268906 0
None
Name [1] 268906 0
Address [1] 268906 0
Country [1] 268906 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 271864 0
The Ethical Committee of Copenhagen and Frederiksberg
Ethics committee address [1] 271864 0
Sjaellandsgade 40
2200 Copenhagen N
Ethics committee country [1] 271864 0
Denmark
Date submitted for ethics approval [1] 271864 0
01/11/1999
Approval date [1] 271864 0
04/01/2000
Ethics approval number [1] 271864 0
(KF) 01-261/99:

Summary
Brief summary
Decreased periproshetic bone mineral density (BMD) after total knee arthroplasty (TKA) is well described in the literature. However, it has been predicted from Finite Element Analyse (FEM) studies that altered design of the femoral implant may have an impact on long term periprosthetic bone lose. In a randomized prospective study we followed 25 patients operated on with either a Duracon or Interax TKA to evaluate periprosthetic differences in BMD using DEXA.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 33182 0
Address 33182 0
Country 33182 0
Phone 33182 0
Fax 33182 0
Email 33182 0
Contact person for public queries
Name 16429 0
Matthias Therbo
Address 16429 0
Rigshospitalet, Copenhagen Universty Hospital, orthop. dept. 2162, 2100 Copenhagen OE
Country 16429 0
Denmark
Phone 16429 0
+45 35452360
Fax 16429 0
Email 16429 0
matthias_therbo@yahoo.dk
Contact person for scientific queries
Name 7357 0
Matthias Therbo
Address 7357 0
Rigshospitalet, Copenhagen Universty Hospital, orthop. dept. 2162, 21oo Copenhagen OE
Country 7357 0
Denmark
Phone 7357 0
+45 35452360
Fax 7357 0
Email 7357 0
matthias_therbo@yahoo.dk

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary