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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Date results information initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Comparison study of two different techniques for knee replacement
Scientific title
In patients with osteoarthritis of the knee, are patient specific cutting guides used for total knee joint replacement as good as computer-assisted surgery for patient outcomes?
Secondary ID [1] 253423 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Osteoarthritis of the knee 260969 0
Condition category
Condition code
Musculoskeletal 259106 259106 0 0
Surgery 259280 259280 0 0
Surgical techniques

Study type
Description of intervention(s) / exposure
For patients requiring a total knee replacement a new method has been developed which may improve patient satisfaction levels in terms of function and pain after surgery. Instead of using conventional measuring and cutting equipment and computer-assisted navigation (Control Group), patient-specific cutting guides will be manufactured based on pre-operative Magnetic Resonance Imaging (MRI) scans of the patient's leg (Intervention Group). The patient will have a total knee replacement performed using these cutting guides which will ultimately align the patient’s prosthesis according to their natural leg alignment (as opposed to the convention way where the patient’s leg is aligned according to a mechanical axis of 0 degrees). The procedure will take approximately 45 minutes.
Both groups will receive the same type of implant. Patients will be followed up at 6 weeks, 6 months and 12 months and also have a Computed Tomography (CT) scan at 3 months.
Intervention code [1] 257869 0
Treatment: Devices
Comparator / control treatment
Patients in the Control Group will receive a total knee replacement using conventional methods and equipment where their implant will be positioned so that their leg is a straight line from their hip to their ankle (i.e. mechanical axis of 0 degrees). The procedure will take approximately 45 minutes.

Patients will be randomized to either the Control Group or Intervention Group and will not be told which group they have been assigned to. As a result, patients assigned to the Control Group will also need to have a pre-operative MRI scan.
Patients in the Control Group will also be followed up at 6 weeks, 6 months and 12 months, and also have a Computed Tomography (CT) scan at 3 months.
Control group

Primary outcome [1] 261960 0
To demonstrate, through calculation of Oxford Knee Score at 12 months postoperative, that total knee replacement (TKR) performed using the ShapeMatch Cutting Guide provides improvement from preoperative levels of patient pain and function comparable to the improvement obtained with TKR performed using computer-assisted Navigation.
Timepoint [1] 261960 0
Pre-operatively and 6 weeks, 6 months and 12 months post-operatively.
Secondary outcome [1] 268880 0
The efficacy objective is to compare radiographic, pain, function and health-related quality of life (QOL) between the ShapeMatch Cutting Guide group and the computer-assisted Navigation control group. This objective will be achieved by utilizing the following instruments pre-operatively and at the 6-week, 6-month and 12 month visits:
- Perth CT protocol
- AP and ML X-rays
- The International Knee Society Score (IKSS)
- The Forgotten Joint Score (FJS-12)
- EQ-5D
- VAS Pain
Timepoint [1] 268880 0
Pre-operatively and 6 weeks, 6 months and 12 months post-operatively.
Secondary outcome [2] 268881 0
To compare the cost-effectiveness and cost-utility of the procedure between the ShapeMatch Cutting Guide group and the computer-assisted Navigation control group. This objective will be assessed by recording and calculating the following parameters:
- Wound length
- Total duration of operating procedure (anaesthetic time and skin-to-skin incision time)
- Cost of consumable items used during operating procedure
- Length of stay in hospital
- Quality-adjusted life-years (QALYs) from EQ-5D
Timepoint [2] 268881 0
Intra-operatively, at hospital discharge and at 6 weeks, 6 months and 12 post-operatively.

Key inclusion criteria
- The patient is a male or non-pregnant female between the ages of 50-80.
- The patient requires a primary total knee replacement and is indicated for computer-assisted surgery.
- The patient has a primary diagnosis of osteoarthritis (OA).
- The patient has intact collateral ligaments.
- The patient is able to undergo MRI scanning of the affected limb.
- The patient has signed the study specific, HREC-approved, Informed Consent document.
- The patient is willing and able to comply with the specified pre-operative and post-operative clinical and radiographic evaluations.
Minimum age
40 Years
Maximum age
80 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
- The patient has a history of total, unicompartmental reconstruction or fusion of the affected joint.
- Patient has had a high tibial osteotomy or femoral osteotomy.
- The patient is morbidly obese (BMI is greater than or equal to 40).
- The patient has a deformity which will require the use of stems, wedges or augments in conjunction with the Triathlon Total Knee System.
- The patient has varus or valgus malalignment greater than or equal to 15 degrees (relative to mechanical axis).
- The patient has a fixed flexion deformity greater than or equal to 15 degrees.
- The patient has a neuromuscular or neurosensory deficiency, which would limit the ability to assess the performance of the device.
- The patient has a systemic or metabolic disorder leading to progressive bone deterioration.
- The patient is immunologically suppressed or receiving steroids in excess of normal physiological requirements.
- Patient has a cognitive impairment, an intellectual disability or a mental illness.
- The patient is pregnant.
- The patient has metal hardware present in the region of the hip, knee or ankle (as this is known to create geometrical distortion in the region of the implant).
- The patient has any known contraindications for undergoing assessment by MRI (e.g. ferrous implants, metallic clips, magnetically activated implanted devices such as cardiac pacemakers, etc).

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Patients will be enrolled in the study after signing the informed consent form and meeting the inclusion and exclusion criteria. If participants met these criteria they will be randomised to either the Control Group or the Intervention Group.
This will be achieved via a block randomisation process. A central randomisation list will be computer generated by a consultant statistician. Once a patient has met criteria for enrolment, the Principal Investigator or designee will phone/email the Sponsor with the Initials, Date of Birth and Patient Number (assigned in ascending order at time of recruitment). A randomisation number, corresponding to a randomisation envelope held at the study site, will be provided. Once this number is received the envelope will be located and opened. The Principal Investigator will note the group allocation in the Case Report Form.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
A computer will generate a randomisation sequence which will allocate each study number to either the control group or the intervention group.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

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

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 3142 0
New Zealand
State/province [1] 3142 0

Funding & Sponsors
Funding source category [1] 258337 0
Commercial sector/Industry
Name [1] 258337 0
Stryker Australia
Address [1] 258337 0
8 Herbert Street
St Leonards, Sydney
NSW 2065
Country [1] 258337 0
Primary sponsor type
Commercial sector/Industry
Stryker Australia
8 Herbert Street
St Leonards, Sydney
NSW 2065
Secondary sponsor category [1] 257598 0
Name [1] 257598 0
Address [1] 257598 0
Country [1] 257598 0

Ethics approval
Ethics application status
Ethics committee name [1] 260394 0
Northern X Regional Ethics Committee
Ethics committee address [1] 260394 0
3rd Floor, Unisys Building
650 Great South Road, Penrose, Auckland, NZ
Ethics committee country [1] 260394 0
New Zealand
Date submitted for ethics approval [1] 260394 0
Approval date [1] 260394 0
Ethics approval number [1] 260394 0

Brief summary
Traditionally the goal of the knee replacement has been to position the components such that the alignment goal is a straight limb, or a mechanical axis of 0 degrees. This has been considered desirable from an engineering point of view to maximise implant longevity, however patient satisfaction of total knee replacement has not always been ideal.

The opportunity exists to provide an alternative approach to total knee replacement surgery which may improve patient outcomes. One such approach is to determine the optimal placement of components based on the individual anatomy of patients, rather than a generic limb alignment philosophy. A three-dimensional description of the anatomy can be obtained by magnetic resonance imaging (MRI) scans obtained pre-operatively. It is then possible to develop a model of the arthritic bone and cartilage, adapt that model to take into account degenerative processes, and generate a model of the pre-arthritic anatomy. The pre-arthritic state then becomes the surgical goal in terms of limb alignment. Custom cutting guides are generated for each individual patient to enable the surgeon to perform the bone resections in such a way that the resultant construct with the total knee replacement components reproduces the pre-disease limb alignment.

The aim of the study is to observe whether there is any difference in outcome following a total knee replacement in terms of pain and function at early follow-up (6 weeks, 6 months and 12 months) between the ShapeMatch Cutting Guide group and the control group. Radiographic, pain, function and health-related quality of life will be compared between both groups using various questionnaires which patients will complete prior to the operation and at 6 weeks, 6 months and 12 months following their total knee replacement.

The study will also aim to compare the cost-effectiveness and cost-utility of the procedure between the ShapeMatch group and the Navigation group by recording and calculating various parameters including total duration of operating procedure and length of stay in hospital following the operation.
Trial website
Trial related presentations / publications
Young, S.W., Walker, M., Bayan, A., Briant-Evans, T., Pavlou, P. and Farrington, B., 2017. No difference in 2-year functional outcomes using kinematic versus mechanical alignment in TKA: a randomized controlled clinical trial. Arthroscopy, 33(10), p.e115.
Public notes

Principal investigator
Name 32099 0
Dr Bill Farrington
Address 32099 0
North Shore Hospital
Shakespeare Road
North Shore City
Auckland 0622
Country 32099 0
New Zealand
Phone 32099 0
64 21 221 4002
Fax 32099 0
Email 32099 0
Contact person for public queries
Name 15346 0
Mrs Simone Mclean
Address 15346 0
Clinical Research Associate II. Stryker Australia 8 Herbert Street ST LEONARDS NSW 2065
Country 15346 0
Phone 15346 0
61 2 9467 1281
Fax 15346 0
Email 15346 0
Contact person for scientific queries
Name 6274 0
Dr David Fulker
Address 6274 0
Clinical Research Associate. Stryker Australia 8 Herbert Street ST LEONARDS NSW 2065
Country 6274 0
Phone 6274 0
61 2 9467 1072
Fax 6274 0
Email 6274 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
What supporting documents are/will be available?
No other documents available
Summary results
Have study results been published in a peer-reviewed journal?
Journal publication details
Publication date and citation/details [1] 2915 0
Young, Simon & L. Walker, Matthew & Bayan, Ali & Briant-Evans, Toby & Pavlou, Paul & Farrington, Bill. (2016). The Chitranjan S. Ranawat Award: No Difference in 2-year Functional Outcomes Using Kinematic versus Mechanical Alignment in TKA: A Randomized Controlled Clinical Trial. Clinical Orthopaedics and Related Research. 475. 10.1007/s11999-016-4844-x.
Attachments [1] 2915 0
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary