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Trial registered on ANZCTR


Registration number
ACTRN12620000089932
Ethics application status
Approved
Date submitted
11/12/2019
Date registered
3/02/2020
Date last updated
3/02/2020
Date data sharing statement initially provided
3/02/2020
Type of registration
Prospectively registered

Titles & IDs
Public title
Accuracy of a new navigation system for total hip replacement
Scientific title
Concurrent validity of intraoperative imageless navigation (Naviswiss™) for component positioning accuracy in primary total hip arthroplasty: A prospective observational cohort study in a single-surgeon practice with three-dimensional reconstruction of computed tomography as gold standard
Secondary ID [1] 300039 0
None
Universal Trial Number (UTN)
U1111-1245-2469
Trial acronym
Linked study record
This study is a sub-study of ACTRN12618000317291, incorporating a subset of the patients eligible for inclusion in the patient registry.

Health condition
Health condition(s) or problem(s) studied:
Hip Osteoarthritis 315574 0
Hip Rheumatoid Arthritis 315575 0
Osteonecrosis of the Femoral Head 315576 0
Condition category
Condition code
Musculoskeletal 313864 313864 0 0
Osteoarthritis
Musculoskeletal 313865 313865 0 0
Osteoarthritis
Surgery 313925 313925 0 0
Surgical techniques
Musculoskeletal 313926 313926 0 0
Other muscular and skeletal disorders

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
Total Hip Arthroplasty with a cemented standard stem and cementless acetabular cup, using an anterolateral approach. Guidance for component positioning will be provided intraoperatively using the Naviswiss image-free navigation system, as is standard for this surgeon. The Naviswiss system uses single-use tags which are pinned to relevant anatomical regions, and a handheld camera to collect measurements relevant to positioning of the hip implants both before, during and after component insertion.

As per the surgeon's standard practice, the same patients will undergo a preoperative, and a follow-up CT scan at 6-8 weeks following surgery (therefore the total observation duration will be 6-8 weeks). These scans will be used to provide positioning measurements which will be compared to those obtained in surgery with the navigation device.
Intervention code [1] 316328 0
Not applicable
Comparator / control treatment
Computed tomography, completed pre and postoperatively, with measurements compared to those obtained with the navigation device from the same patients.
Control group
Active

Outcomes
Primary outcome [1] 322255 0
Validity of Naviswiss measurements of acetabular cup inclination.
Assessed by comparison between intraoperative Naviswiss and postoperative CT-based measurements (standard error of measurement).
Timepoint [1] 322255 0
6-12 weeks postoperative
Primary outcome [2] 322256 0
Validity of Naviswiss measurements of acetabular cup anteversion.
Assessed by comparison between intraoperative Naviswiss and postoperative CT-based measurements (standard error of measurement).
Timepoint [2] 322256 0
6-12 weeks postoperative
Primary outcome [3] 322257 0
Validity of Naviswiss measurements of change in femoral offset pre-post implant.
Assessed by comparison between intraoperative Naviswiss measurements, and pre and postoperative CT-based measurements (standard error of measurement).
Timepoint [3] 322257 0
6-12 weeks postoperative
Secondary outcome [1] 377893 0
Validity of Naviswiss measurements of change in leg length pre-post implant.
Assessed by comparison between intraoperative Naviswiss measurements, and pre and postoperative CT-based measurements (standard error of measurement).
Timepoint [1] 377893 0
6-12 weeks postoperative
Secondary outcome [2] 377894 0
Inter-observer reliability of CT measurements. Two external observers will perform measurements of the listed outcomes using medical image analysis software, on a random selection of ten cases.
Timepoint [2] 377894 0
6-12 weeks postoperative
Secondary outcome [3] 378073 0
Intra-observer reliability of CT measurements. One observer will perform measurements of the listed outcomes using medical image analysis software, on a random selection of ten cases twice, with each measurements made at least two weeks apart.
Timepoint [3] 378073 0
6-12 weeks postoperative

Eligibility
Key inclusion criteria
Patients eligible for primary elective THA using an anterolateral approach in the supine position
Minimum age
18 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Patients who have declined or revoked consent for use of clinical data for research, or unable to provide informed consent.

Patients requiring/electing to have simultaneous bilateral procedures

Patients with severe contralateral hip deformity or dysplasia

Patients eligible for insertion of a short-stem component

Patients with previous ipsilateral hip arthroplasty eligible for revision

Study design
Purpose
Duration
Selection
Timing
Statistical methods / analysis
The sample size was established to provide adequate power to detect a 2.5° absolute mean difference between intraoperative navigation results and postoperative CT measurements for inclination and version using a paired t-test design (each patient acts as their own control), with an assumed between-patient standard deviation of 5°. The standard deviation was estimated from an initial pilot of 15 cases during the learning curve (2.4° for inclination and 2° for version) with an additional margin of error added. Power (beta) was selected at 0.8 and alpha of 0.05 with an estimated sample size of 34 cases required.

The intraoperative data and postoperative CT measurements of the primary outcomes by the primary observer will be compared using mixed effects linear regression. The sample size necessary for the multivariable regression analysis (N = 30) with patient age at surgery, sex and body mass index selected as the model predictors was estimated from a model R-squared of 0.3, three predictors and the same beta and alpha.

The sample size necessary to establish intra and inter-observer reliability of the post-operative CT measurements (N = 10) was estimated from a two-sided test of correlation within and between observers, with an R-squared of 0.5 and a beta/alpha ratio of 1. A sample of 10 cases also provides a 95% confidence interval around the primary and secondary observer average estimates with a 95% confidence interval around a margin of error of 3° (version/inclination) and a standard deviation of 5°.

Recruitment
Recruitment status
Not yet recruiting
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 in Australia
Recruitment state(s)
NSW
Recruitment hospital [1] 15455 0
Wollongong Private Hospital - Wollongong
Recruitment hospital [2] 15456 0
Campbelltown Private Hospital - Campbelltown
Recruitment postcode(s) [1] 28807 0
2500 - Wollongong
Recruitment postcode(s) [2] 28808 0
2560 - Campbelltown

Funding & Sponsors
Funding source category [1] 304493 0
Commercial sector/Industry
Name [1] 304493 0
Naviswiss AG
Address [1] 304493 0
Stahlrain 2, 5200 Brugg
Country [1] 304493 0
Switzerland
Primary sponsor type
Individual
Name
John Ireland
Address
Sydney Bone and Joint Clinic
Building B, Suite 101/4 Hyde Parade,
Campbelltown NSW 2560
Country
Australia
Secondary sponsor category [1] 304760 0
Commercial sector/Industry
Name [1] 304760 0
Naviswiss
Address [1] 304760 0
Stahlrain 2, 5200 Brugg
Country [1] 304760 0
Switzerland
Secondary sponsor category [2] 304783 0
Commercial sector/Industry
Name [2] 304783 0
Active Surgical Pty Ltd
Address [2] 304783 0
138 Milson Rd,
Cremorne Point NSW 2090
Country [2] 304783 0
Australia
Other collaborator category [1] 281094 0
Commercial sector/Industry
Name [1] 281094 0
EBM Analytics
Address [1] 281094 0
119 Willoughby Road,
Crows Nest NSW 2065
Country [1] 281094 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 304926 0
Bellberry Ltd
Ethics committee address [1] 304926 0
129 Glen Osmond Road, Eastwood, SA 5063
Ethics committee country [1] 304926 0
Australia
Date submitted for ethics approval [1] 304926 0
Approval date [1] 304926 0
03/01/2018
Ethics approval number [1] 304926 0
HREC2017-07-499

Summary
Brief summary
Optimal outcomes in total hip arthroplasty are dependent on appropriate component placement, with technological advances providing a platform for guiding component placement to reduce the risk of malpositioned components during surgery. This study will validate the accuracy of the data captured using a handheld imageless navigation system (for total hip arthroplasty) against pre/postoperative CT scans.

Patients are to be recruited and data captured as part of the existing approved protocol for John Ireland's patient registry [ACTRN12618000317291].
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 98658 0
A/Prof John Ireland
Address 98658 0
Sydney Bone and Joint Clinic
Building B, Suite 101/4 Hyde Parade,
Campbelltown NSW 2560
Country 98658 0
Australia
Phone 98658 0
+61 298212599
Fax 98658 0
Email 98658 0
dr.ireland@sbjc.com.au
Contact person for public queries
Name 98659 0
Ms Claire sinclair
Address 98659 0
Sydney Bone and Joint Clinic
Building B, Suite 101/4 Hyde Parade,
Campbelltown NSW 2560
Country 98659 0
Australia
Phone 98659 0
+61 298212599
Fax 98659 0
Email 98659 0
claire.sinclair@sbjc.com.au
Contact person for scientific queries
Name 98660 0
Dr Corey Scholes
Address 98660 0
119 Willoughby Road,
Crows Nest NSW 2065
Country 98660 0
Australia
Phone 98660 0
+61 299563800
Fax 98660 0
Email 98660 0
cscholes@ebma.com.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
The data obtained during this study contains both identifiable patient data and commercially sensitive information, and is thus not suitable for sharing.
What supporting documents are/will be available?
Study protocol
Ethical approval
How or where can supporting documents be obtained?
Type [1] 6144 0
Study protocol
Citation [1] 6144 0
Link [1] 6144 0
Email [1] 6144 0
cscholes@ebma.com.au
Other [1] 6144 0
The study protocol will be published as a preprint article prior to the commencement of the study. A link will be posted here when this is complete.
Attachment [1] 6144 0
Type [2] 6145 0
Ethical approval
Citation [2] 6145 0
Link [2] 6145 0
Email [2] 6145 0
cscholes@ebma.com.au
Other [2] 6145 0
Attachment [2] 6145 0
Summary results
No Results