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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
Retrospectively registered

Titles & IDs
Public title
Clinical evaluation of a novel suture anchor for rotator cuff repairs – ATOK Anchor
Scientific title
Evaluation of a novel suture anchor compared to a historical controls on repair integity and function in patients with rotator cuff tear.
Secondary ID [1] 287285 0
nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Patients over the age of 60, with a less than 3cm rotator cuff tear involving the supraspinatus and at least part of the infraspinatus tendons. Patients will have failed non-operative management. 295919 0
Condition category
Condition code
Surgery 296171 296171 0 0
Surgical techniques
Musculoskeletal 296253 296253 0 0
Other muscular and skeletal disorders

Study type
Description of intervention(s) / exposure
Repair of rotator cuff tear using an arthroscopic technique, utilizing a new anchor to secure the transosseous sutures to the lateral humeral cortex.
The repair will idealy performed using an arthroscopic however a mini-open approach may be utilised if there is inadequate visualisation, or concerns about seating of the implant.
The novel anchor to be used is the Arthroscopic Trans-Osseous Knotless (ATOK) anchor. Generally 2 anchors are used. The procedure will be performed under a general anaesthetic and by an orthopaedic surgeon, who is the principal investigator.
The procedure is anticipate to take between 30 and 60 minutes and will where appropriate be combined with an acromioplasty, or lateral clavicle excision.
The anchor is inserted percutaneously through the lateral arm muscle and into the humeral cortex. The suture are passed and secured using the locking plug.
There are no exactly similar studies on such a challenging group of patients, however, changes in outcome scores and displacement of anchors based on MRI review are the critical review end points.
The patients will undergo the surgery between July 2015 and July 2016, with assessment of anchor position at 1 and 6 months, tendon healing at 6 months, and functional outcomes progressively from 3 months out to 2 years.
Intervention code [1] 298199 0
Treatment: Devices
Intervention code [2] 298227 0
Treatment: Surgery
Comparator / control treatment
Comparison controls will be with previously publlished series and relates to rupture and re-tear rate as well as functional outcomes.
The most relevent comparator published study is:
Boileau P, Brassart N, Watkinson DJ, Carles M, Hatzidakis AM, Krishnan SG. Arthroscopic repair of full-thickness tears of the supraspinatus: does the tendon really heal? J Bone Joint Surg Am. 2005;87:1229–1240.

The initial study aim is to assess safety and general efficacy, but without the precision to compare to an alternate technique.
The comparator is a benchmark study using arthroscopic repairs using standard techniques and a variety of anchors. The outcomes are generally favourable using existing anchors, however, the new anchor aims to address difficult patients where the proximal humeral bone is quite osteoporotic and prone to lead to pull out of currently used anchors.
There are no exactly similar studies on such a challenging group of patients, however, changes in outcome scores and displacement of anchors based on MRI review are the critical review end points.

Historical controls will those gleaned from published data which most closely matches the patient group. There are not truly comparative cohort.
Control group

Primary outcome [1] 295843 0
Repair of rotator cuff tear, assessed by MRI; timepoint- 6 months post surgery.
Timepoint [1] 295843 0
6 months
Primary outcome [2] 295910 0
Shoulder function, assessed on Constant, Oxford Shoulder Score
Timepoint [2] 295910 0
6 and 12 months post surgery.
Primary outcome [3] 295911 0
Non-displacement of ATOK anchors as identified on MRI
Timepoint [3] 295911 0
one month and 6 months post surgery
Secondary outcome [1] 316711 0
Functional outcome based on Constant and Oxford Sholder score
Timepoint [1] 316711 0
2 years post surgery

Key inclusion criteria
Patients with rotator cuff tears, less than 3cm, and over 60 years of age.
Failed 3 months of of targeted conservative therapy.
These patients are likely to have osteoporosis of the proximal humerus, but such bone changes will not be quantified.
Minimum age
60 Years
Maximum age
80 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Arthritis of the shoulder
Unable to understand the trial due to language or comprehension
Significant loss of motion

Study design
Purpose of the study
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Who is / are masked / blinded?

Intervention assignment
Other design features
Phase 1
Type of endpoint(s)
Statistical methods / analysis
The number of participants was determined on the number of potential patients likely to be recruited over a 12 month period.
This is a pilot study to assess anchor integrity and potential for displacement as well as ability to achieve rotator cuff healing at a rate, at least as good as existing published results.
Sample size calculation was not formally performed. Once 20 patients have been recruited and followed for 12 months, a formal comparative trial will be considered.
At any stage if there is displacement of the anchors, the trial is likely to be terminated, unless there are reasons for the failure can be reasonable explained, such as technical error, or additional trauma.
Pre and 6, 12 and 24 month functional outcomes will be statistically compared.

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] 4197 0
Calvary Wakefield Hospital - Adelaide
Recruitment hospital [2] 4198 0
Parkwynd Private Hospital - Adelaide
Recruitment hospital [3] 4199 0
St Andrew's Hospital Inc - Adelaide
Recruitment postcode(s) [1] 10110 0
5000 - Adelaide

Funding & Sponsors
Funding source category [1] 291841 0
Commercial sector/Industry
Name [1] 291841 0
Wright Medical
Address [1] 291841 0
3/17 Rodborough Rd, Frenchs Forest
NSW 2086

PO Box 6052,
Frenchs Forest NSW 1640, Australia
Country [1] 291841 0
Primary sponsor type
Assoc Prof Michael Sandow
Wakefield Orthopaedic Clinic
270 Wakefield Street,
SA 5000
Secondary sponsor category [1] 290509 0
Commercial sector/Industry
Name [1] 290509 0
Macropace Products Pty Ltd
Address [1] 290509 0
14 Hauteville Terrace
Eastwood SA 5063
Country [1] 290509 0

Ethics approval
Ethics application status
Ethics committee name [1] 293358 0
Human Research Ethics Committee, Royal Adelaide Hospital
Ethics committee address [1] 293358 0
Royal Adelaide Hospital :-
Level 4, Women’s Health Centre, Royal Adelaide Hospital
North Terrace, Adelaide SA 5000
Ethics committee country [1] 293358 0
Date submitted for ethics approval [1] 293358 0
Approval date [1] 293358 0
Ethics approval number [1] 293358 0

Brief summary
Purpose of study to investigate the safety and efficacy of a novel attempt to achieve trans osseous repair of disrupted or torn rotator cuff using the knotless technique.

This is essentially a safety and efficacy trial to confirm the biomechanical advantages in a clinical setting of the recently designed arthroscopic trans-osseous knotless technique using an ATOK implant.
Trial website
Trial related presentations / publications
Public notes
Attachments [1] 540 540 0 0

Principal investigator
Name 59566 0
A/Prof Michael Sandow FRACS
Address 59566 0
Wakefield Orthopaedic Clinic
270 Wakefield Street
SA 5000
Country 59566 0
Phone 59566 0
+61 8 8236 4166
Fax 59566 0
Email 59566 0
Contact person for public queries
Name 59567 0
A/Prof Michael Sandow FRACS
Address 59567 0
Wakefield Orthopaedic Clinic
270 Wakefield Street
SA 5000
Country 59567 0
Phone 59567 0
+61 8 8236 4166
Fax 59567 0
Email 59567 0
Contact person for scientific queries
Name 59568 0
A/Prof Michael Sandow FRACS
Address 59568 0
Wakefield Orthopaedic Clinic
270 Wakefield Street
SA 5000
Country 59568 0
Phone 59568 0
+61 8 8236 4166
Fax 59568 0
Email 59568 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
Confidentially stored
What supporting documents are/will be available?
Study protocol
Statistical analysis plan
Informed consent form
Clinical study report
Ethical approval
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