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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
The use of accelerometer-based, computer navigation versus conventional alignment guides in achieving accurate implant position for Total Knee Replacement surgery
Scientific title
Conventional versus accelerometer-based, portable navigation system (KneeAlign 'Registered Trademark') for total knee arthroplasty: A prospective randomized comparative trial.
Secondary ID [1] 287999 0
Nil Known
Universal Trial Number (UTN)
Trial acronym
TKA (Total Knee Arthroplasty)
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Total Knee Arthroplasty for Knee Osteoarthritis 296878 0
Condition category
Condition code
Surgery 297109 297109 0 0
Surgical techniques
Musculoskeletal 297498 297498 0 0

Study type
Description of intervention(s) / exposure
A comparison of alignment outcomes of total knee arthroplasty (TKA) using accelerometer based navigation vs traditional intramedullary guides.
Navigation will be performed using KneeAlign2 (OrthAlign, Aliso Viejo, CA) which is a handheld, accelerometer-based surgical navigation system consisting of a display console and reference sensor designed to assist the surgeon in performing accurate proximal tibia and distal femur cuts in both the coronal and sagittal planes.
Surgeries will be performed by a fellowship trained orthopedic surgeons (Samuel Macdessi and Darren Chen), and the expexted duration of surgery from skin incision to application of dressing is around 1.5 hour.
Intervention code [1] 293336 0
Treatment: Surgery
Comparator / control treatment
Control group:
Total knee artroplasty using traditional intramedullary guides for both femur and tibial cuts. in this technique the cutting jigs for the proximal tibia and distal femur correlates with the anatomical axes for the tibia and femur respectively identified by inserting a fitting rigid rod in the medullary canals.
Surgeries will be performed by a fellowship trained orthopedic surgeons (Samuel Macdessi and Darren Chen), and the expexted duration of surgery from skin incision to application of dressing is around 1.5 hour.
Control group

Primary outcome [1] 296721 0
Overall lower limb alignment in the coronal plane assessed by Computed Tomography (CT) imaging based on the Perth protocol.
Timepoint [1] 296721 0
Second day post surgery
Primary outcome [2] 297124 0
Individual component alignment (tibial component) in the coronal, sagittal and axial planes assessed by CT Perth protocol
Timepoint [2] 297124 0
Second day post surgery
Primary outcome [3] 297125 0
Individual component alignment (femoral component) in the coronal, sagittal and axial planes assessed by CT Perth protocol.
Timepoint [3] 297125 0
Second day post surgery
Secondary outcome [1] 319194 0
Knee function and pain will be assessed using the Knee Society Score (KSS)

Timepoint [1] 319194 0
- Preoperatively
- 6 weeks postoperatively
- 6 months postoperatively
Secondary outcome [2] 319940 0
knee function and patient symptoms will be assessed by Knee Injury and Osteoarthritis Outcome Score (KOOS)
Timepoint [2] 319940 0
- Preoperatively
- 6 weeks postoperatively
- 6 months postoperatively

Key inclusion criteria
Age 40 - 90
No racial nor gender bias
Undergoing unilateral TKA for degenerative osteoarthritis
Minimum age
40 Years
Maximum age
90 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
* Revision TKA surgery
* Bilateral simultaneous TKA
* Prior osteotomies around the knee or extra-articular deformities
* Systemic inflammatory disease (e.g. Rheumatoid arthritis, Systemic lupus erythematosus, etc)
* Medial and lateral knee ligamental instability & prior surgery specific to this
* Knee replacement for acute trauma
* Need for allograft, , constrained implants, stemmed components or metal augmentation during surgery

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation is not concealed
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by computer software
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
* Pre:
Based on power analysis, a sample size of 70 patients in each cohort would provide appropriate power (beta level = 0.80, alpha level = 0.05) to detect a 20% improvement in accuracy between the two groups (obtaining femoral & tibial resections to within 2 degrees of their respective mechanical axes).
* During:
There will be a midterm analysis when 100 patients are recruited to assess whether significance has been reached and whether or not, further patient enrollment is necessary.
* Post:
Student’s t-tests to compare differences in means between continuous variables
Fisher’s exact test for significance in difference of alignment (proportions) between groups
Statistical significance was set at p<0.05

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 4729 0
St George Private Hospital - Kogarah
Recruitment hospital [2] 4730 0
Canterbury Hospital - Campsie
Recruitment postcode(s) [1] 12289 0
2217 - Kogarah
Recruitment postcode(s) [2] 12290 0
2194 - Campsie

Funding & Sponsors
Funding source category [1] 292459 0
Self funded/Unfunded
Name [1] 292459 0
Address [1] 292459 0
Country [1] 292459 0
Primary sponsor type
Other Collaborative groups
Sydney Knee Specialists
19 Kensington street
Kogarah 2217
Secondary sponsor category [1] 291158 0
Name [1] 291158 0
Address [1] 291158 0
Country [1] 291158 0

Ethics approval
Ethics application status
Ethics committee name [1] 293922 0
Hunter New England Research Support and Development Office/ Research Office and Governance Unit
Ethics committee address [1] 293922 0
Locked bag 1, New Lambton, NSW, 2305
Ethics committee country [1] 293922 0
Date submitted for ethics approval [1] 293922 0
Approval date [1] 293922 0
Ethics approval number [1] 293922 0

Brief summary
The KneeAlign 'Registered Trademark' is an accelerometer-based, electronic, portable device which was designed for use in navigational total knee arthroplasty. There is literature which supports its efficacy and safety in achieving satisfactory knee alignment following total knee arthroplasty. However, most studies on the device has come from the designer unit and further information gathered from independent operators will be important. Its potential benefit is in the area of navigated arthroplasty as it is less-bulky than current navigation equipment and may prove important in complex surgeries where navigation is most useful. The risks are minimal and may even protect the medullary canal (as this is invaded using conventional alignment guides). The patient receives the same implant by the same surgeon and this device is to be used solely as an aid in achieving accurate bony cuts during surgery.
This study will compare conventional guides and the navigation device in question. The trial will be conducted in compliance with the protocol laid out, GCP and the ethics regulations. The study will look at patients who are undergoing routine total knee replacement for osteoarthritis (the most common reason for prosthetic replacement).

Trial Objectives:
To prospectively compare patient-reported outcome measures and radiological results between conventionally guided and accelerometer-based navigation in patients undergoing total knee replacement surgery. Specifically, we will compare pain and functional scores together with mechanical axes correction in both sagittal and coronal planes.

trial will be a prospective, patient-blinded, randomised comparative study with the end-points being patient-reported outcome measures, radiological results and duration of surgery. Patient consent and ethical approval will be obtained prior to trial commencement.

Clinical outcome measures would be assessed via the Knee Society Score (KSS) and the Knee Injury and Osteoarthritis Outcome score (KOOS) questionnaires which are both validated patient reported outcome measures following knee arthroplasty. These questionnaires will be taken at the time of standard appointments (pre-surgery & 6 months). Radiological outcomes will be assessed via CT imaging studies pre and post op using the CT Perth Protocol (To assess for mechanical & anatomical alignment).
Patients will be recruited at the time when a decision to proceed with a knee arthroplasty is made during consultation.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 61822 0
Dr Samuel Macdessi
Address 61822 0
Sydney Knee Specialists, Suite 8, 19, Kensington St, Kogarah NSW 2217
Country 61822 0
Phone 61822 0
Fax 61822 0
Email 61822 0
Contact person for public queries
Name 61823 0
Dr Samuel Macdessi
Address 61823 0
Sydney Knee Specialists, Suite 8, 19, Kensington St, Kogarah NSW 2217
Country 61823 0
Phone 61823 0
Fax 61823 0
Email 61823 0
Contact person for scientific queries
Name 61824 0
Dr Samuel Macdess
Address 61824 0
Sydney Knee Specialists, Suite 8, 19, Kensington St, Kogarah NSW 2217
Country 61824 0
Phone 61824 0
Fax 61824 0
Email 61824 0

No information has been provided regarding IPD availability
Summary results
No Results