Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12610000923066
Ethics application status
Approved
Date submitted
28/10/2010
Date registered
29/10/2010
Date last updated
29/10/2010
Type of registration
Retrospectively registered

Titles & IDs
Public title
The Visionaire Cutting Block System - An Outcome Study
Scientific title
Evaluation of Limb and Component Alignment, Cost and Surgical Time Compared to Conventional Total Knee Arthroplasty Methods Following Total Knee Arthroplasty with Smith and Nephew Visionaire Patient-Matched Instrumentation
Secondary ID [1] 252976 0
2010023 - Ethics of Human Research Committee
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Osteoarthritis of the Knee 258500 0
Condition category
Condition code
Surgery 258670 258670 0 0
Surgical techniques
Musculoskeletal 258671 258671 0 0
Osteoporosis

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Currently knee replacement surgery is performed using external jigs or a computer navigation system to guide bone cuts necessary to implant the metal and plastic prosthesis. The computer navigation system is considered the most accurate for guiding and evaluating the cuts but it has been shown to increase surgery time. Many surgeons still prefer the conventional external jigs calculating alignment with an intra medullary rod for the femoral component and an external rod to align the tibial component. These surgeons feel the time saved by using the conventional methods outweigh the small increase in alignment accuracy achieved by the navigation technique. There is however new technology developed that allows patient-specific instruments to be manufactured based on a pre-operative magnetic resonance imaging [MRI] scan and x-rays of the affected knee. These instruments should allow bone cuts and thus implants to be positioned more accurately than conventional intra-medullary rod method in addition to decrease overall surgical time. Additional factors are that much less equipment is needed when using the patient-specific instruments as the prosthesis size is known pre-operatively. This has the potential to cut cost significantly. The current study will include 50 patients that have met the criteria for total knee replacement. The patients will require a pre-operative MRI and full-leg x-rays. Their surgery will be performed with the custom instrumentation. All bone cuts will be evaluated intra-operatively using a micrometer to measure actual bone resection thickness compared to that which is predicted by the MRI data. Any cut that is inappropriate will be revised using the standard conventional alignment method. It will be within the surgeons capacity and at the surgeons discretion whether they over-ride the patient specific jigs and continue with the surgery using conventional techniques for alignment. The surgery time will vary but expected average times will be 80 minutes. The patients will require a post-operative computed tomography [CT] scan to evaluate the limb and implant alignment. This scan will be performed at least 6 weeks post-operatively. The recovery and post-operative follow-up will be unchanged from that expected for routine knee replacement surgery. The participants will also be assessed for range of movement, Knee Society Score, General Health Questionnaire and the Oxford Knee Score pre-operatively, and at three, six and twelve months post operatively.
Intervention code [1] 257499 0
Treatment: Surgery
Comparator / control treatment
None
Control group
Uncontrolled

Outcomes
Primary outcome [1] 259525 0
Limb and component alignment as determined post-operative computed tomography [CT] scan
Timepoint [1] 259525 0
Six weeks post-operatively
Primary outcome [2] 259526 0
Comparative cost between Patient Matched Instrumentation method and Conventional Rod Alignment method
Timepoint [2] 259526 0
Post-operatively
Secondary outcome [1] 266135 0
Comparative surgical time between Patient Matched Instrumentation method and Conventional Rod Alignment method.
Timepoint [1] 266135 0
Imediately post-surgery
Secondary outcome [2] 266136 0
Patients subjective mobility level, ability for self care, pain level, depression/anxiety level, activities of daily living level and knee stability level assessed by General Health Questionnaire, Knee Society Questionnaire and Oxford Knee Questionnaire. Also objective measurements of Knee Flexion, Extention, stability, varus/valgus angle and extension lag assessed by goniometer and recorded in Knee Society Questionnaire.
Timepoint [2] 266136 0
Pre-operatively and at three months, six months and twelve months post-operatively
Secondary outcome [3] 266137 0
Difference between actual bone resection thickness and MRI based predicted resection thickness
Timepoint [3] 266137 0
Intra-operatively

Eligibility
Key inclusion criteria
Patients with osteoarthritis of the knee
Minimum age
20 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Medically unfit for elective surgery.
Pregnancy.
Infection.
Inflammatory arthritis.

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
All patients on the surgical waiting list for participating Orthopaedic surgeons at The Queen Elizabeth Hospital, that are not involved in other orthopaedic trials and who meet the inclusion/exclusion criteria will be offered participation in the study.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Nonrandomised trial
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Single group
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
30/04/2010
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
50
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 257946 0
Commercial sector/Industry
Name [1] 257946 0
Smith and Nephew Surgical Pty Ltd.
Country [1] 257946 0
Australia
Primary sponsor type
Hospital
Name
The Queen Elizabeth Hospital Deptartment of Orthopaedics and trauma
Address
28 Woodville Road
Woodville South
SA 5011
Country
Australia
Secondary sponsor category [1] 257145 0
Individual
Name [1] 257145 0
Mr Gordon Morrison
Address [1] 257145 0
28 Woodville Road
Woodville South
SA 5011
Country [1] 257145 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 259958 0
Central Northern Adelaide health Service Ethics of Human Research Committee (TQEH & LMH)
Ethics committee address [1] 259958 0
28 Woodville Road
Woodville South
SA 5011
Ethics committee country [1] 259958 0
Australia
Date submitted for ethics approval [1] 259958 0
19/03/2010
Approval date [1] 259958 0
27/04/2010
Ethics approval number [1] 259958 0
2010023

Summary
Brief summary
Currently knee replacement surgery is performed using alignment rods that correctly position the cutting blocks which guide bone cuts necessary to implant the metal and plastic total knee joint. Using a computer navigation system during surgery is considered the "gold standard" for guiding the cuts. Many surgeons however find this extends the time of the surgery for what is considered only a marginally better aligned knee and for much of the time the alignment is the same. These surgeons feel that the accuracy of the alignment of the total knee replacement without computer navigation is very good anyway and it is quicker to do. There is however new technology that has been developed that allows patient-specific cutting blocks, which are said to guide the cuts more accurately, to be manufactured based on a an MRI scan and x-ray of the affected knee taken before surgery. In this way it may be possible to have the accuracy of computer navigation in addtion to decreasing surgical time. This would be potentially good for the patients for a number of reasons including shorter operation time resulting in less chance of complications. In addition to this, less instuments will need to be used during surgery because the surgeon will already know the size of the knee replacement needed. This will reduce the cost of surgery while potentially increasing the accuracy. The current study will include 50 patients that have met the criteria for total knee replacement on the waiting list. The patients will require a pre-operative MRI and full-leg x-rays. Their surgery will be performed with the custom instrumentation. All bone cuts will be measured during surgery and compared to the bone cuts the MRI scan predicted. The surgeon can override the custom made blocks at any time and continue surgery in the conventional way if they feel the blocks are in any way inaccurate. The surgery time will vary but on average it should require approximately 80 minutes. The patients will require a post-operative computer tomography [CT] scan to evaluate the limb and implant alignment and information will be collected including pain levels, how far a person can walk and the affected knee's range of motion. This scan will be performed at least 6 weeks after surgery and the other information will be gathered before surgery and also at 3,6 and 12 months after surgery. Otherwise, the recovery and post-operative follow-up will be unchanged from that expected for routine knee replacement surgery. Our hypothesis is that the patient-matched instrumentation will align the bone cuts, implants, and the mechanical axis of the limb at least as well as would be expected using the conventional alignment rods, will cost less and on average speed up the surgery.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 31206 0
Address 31206 0
Country 31206 0
Phone 31206 0
Fax 31206 0
Email 31206 0
Contact person for public queries
Name 14453 0
Mr Graeme West
Address 14453 0
28 Woodville Road
Woodville South
SA 5011
Country 14453 0
Australia
Phone 14453 0
+61 8 82228639
Fax 14453 0
Email 14453 0
[email protected]
Contact person for scientific queries
Name 5381 0
Mr Graeme West
Address 5381 0
28 Woodville Road
Woodville South
SA 5011
Country 5381 0
Australia
Phone 5381 0
+61 8 82228639
Fax 5381 0
Email 5381 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

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