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Trial registered on ANZCTR

Registration number
Ethics application status
Not yet submitted
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
Treatment of Ankle Syndesmosis Injuries
Scientific title
A prospective, randomized study comparing the effect of TightRope (Registered Trademark) suture-button fixation versus conventional screw fixation on post-operative ankle function in patients with a Weber C ankle fracture

Secondary ID [1] 283749 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Weber C ankle Fractures 290722 0
Condition category
Condition code
Surgery 291087 291087 0 0
Surgical techniques
Musculoskeletal 291129 291129 0 0
Other muscular and skeletal disorders
Injuries and Accidents 291130 291130 0 0

Study type
Description of intervention(s) / exposure
This study is investigating the TightRope (Registered Trademark) suture-button fixation implant device , used as an ankle diastasis fixation device.
A single device will be used to surgically fixate the syndesmotic disruption associated with Weber C ankle fractures, which will take approximately 100minutes of operating time..
Intervention code [1] 288436 0
Treatment: Surgery
Intervention code [2] 288474 0
Treatment: Devices
Comparator / control treatment
The standard treatment for syndesmosis fixation is cortical diastasis screws. 2 screws will be used including three to four cortices. The screw diameter will be 4.5mm. The screws will be inserted in standard non-compression mode. The distal screw will be placed 1-1.5cm above the joint line, with the second screw placed 2-3cm proximal to the distal screw, which will take approximately 100minutes of operating time.
Control group

Primary outcome [1] 291071 0
The primary aim of this study is to compare the calculated total cost per injury at the completion of rehabilitation, between the TightRope (Registered Trademark) suture-button fixation device and the syndesmotic screw fixation.
Costing data will be compiled from New Zealand Health specific supply costs and associated billing costs as published by the Wellington Regional Hospital, with regards to cortical screw and TightRope (Registered Trademark) suture-button fixation device costs, theatre time cost for initial procedure, bed day cost, and theatre time for any secondary procedures. The costs associated with the number of orthopedic outpatient clinic appointments attended will be recorded. The number of community based physiotherapy sessions will be recorded and an average cost per session derived. Any associated rehabilitative equipment required will be included in the cost analysis. Furthermore, the time to return to work will be recorded, and an estimated ACC payout based on patient’s salary will recorded.
Timepoint [1] 291071 0
12 months after surgery.
Secondary outcome [1] 305965 0
Secondary outcomes include syndesmotic reduction and it's correlation with clinical outcomes.
Syndesmotic reduction will be will be reviewed by an independent radiologist, who will record the ankle parameters (medial clear space, tibiofibular clear space, tibiofibular overlap) using digital imaging software of the patient radiographs, against the patient’s corresponding individual study number code.
Patient clinical outcomes will be compared using the American Orthopaedics Foot and Ankle Society (AOFAS score), the Foot and Ankle Disability Index (FADI) score, and range of motion. Furthermore; time to full weight bearing, time to return to work, and rate of complications, will be compared against the patient’s corresponding individual study number code.

Both treatment groups will be at risk of bleeding related to the surgery, risk of infection, and pain following the procedure. There is a reported risk of cortical screws malfunctioning, breaking, loosening, and requiring removal at a later date. Of the available literature, these risks have not been reported for the TIghtRope procedure.
These will be assessed via a combination of clinical, biochemical, and radiological assessment, and recorded against the patient's study number.
Timepoint [1] 305965 0
Baseline, and at 6 weeks, 6 months, and 12 months after surgery.

Key inclusion criteria
Patients with a Weber C fracture less than one month old, aged between 18 – 60 years of age, with a body mass index (BMI) less than 35, and are able to provide informed consent.
Minimum age
18 Years
Maximum age
60 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Individuals not able to give informed consent; dementia or inability to comply with instructions; those with, neuropathic arthropathy, open fractures, multi trauma, bilateral injuries, and open growth plates.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Eligible patients will be invited to take part in this research study by the orthopaedic registrar and/or consultant who initially assesses and consents the patient for surgery. They will discuss the study and the possible operative interventions and why the need for the study. The participants will be provided with information sheets, detailing the purpose of the study, the current evidence for both surgical procedures, and the requirements of study follow up. Patients will be informed of potential risks and discomforts for both procedures. They will be encouraged to ask questions and to discuss their decision to participate in research with family / whanau members. Patients will be enrolled once written consent has been received.
Once the patient has agreed to participate in the study, and signed the consent form, the patient will be registered with the study coordinator, randomized to either procedure and allocated a unique study number.
Individuals who decide not to participate will be treated by the standard surgical approach using fixation by syndesmotic screws.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomization will be based on computerized blocked randomization to either surgical intervention utilizing the flexible endo-button implant procedure, or the cortical screw approach. Following enrollment with informed consent, the consenting orthopaedic registrar/consultant will inform an independent study administrator, who will allocate the patient a unique study number and surgical intervention based upon the blocked randominzation sequence.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
This study will accrue a total of 68 eligible patients per group. The sample size calculation was performed firstly on cost analysis, based on previous Weber C surgery cost data. The average total cost of standard cortical screw fixation was $10581.75 NZD (SD +/- $3336.55 NZD), and the average Tightrope fixation cost was calculated to be $8970.75 NZD. Secondly based on the measurements of normal syndesmosis on plain radiography (Shah, et al. 2012), the mean tibiofibular medial clear space on AP radiographs was 4.6mm (SD +/- 1.1mm).
Based on a 2-group comparison, power calculations indicated that a minimum of 136 participants (68 in each group) will be required to detect a significant cost difference at a 95% level of confidence and a power of 80%. Using this sample size, at a 95% level of confidence, a power of 100% can be utilized to detect a radiological difference of 1mm of the tibiofibular medial clear space.

Statistical analysis will be performed using standard computer software. Demographics will be compared for the two groups using mean values and proportions. Mean values will also be calculated for the radiographic parameters, with the Student t test to be used to analyze data regarding malreduction. Mean values will be used to compare clinical outcome scores and cost effectiveness.

Recruitment status
Not yet recruiting
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] 5677 0
New Zealand
State/province [1] 5677 0

Funding & Sponsors
Funding source category [1] 288431 0
Name [1] 288431 0
Wellington Regional Hospital,
Capital and Coast District Health Board
Address [1] 288431 0
Wellington Hospital
Riddiford Street
Wellington 6021
Country [1] 288431 0
New Zealand
Primary sponsor type
Capital and Coast District Health Board
Wellington Hospital
Riddiford Street
Wellington 6021
New Zealand
Secondary sponsor category [1] 287134 0
Name [1] 287134 0
Address [1] 287134 0
Country [1] 287134 0

Ethics approval
Ethics application status
Not yet submitted
Ethics committee name [1] 290306 0
Ethics committee address [1] 290306 0
Ethics committee country [1] 290306 0
New Zealand
Date submitted for ethics approval [1] 290306 0
Approval date [1] 290306 0
Ethics approval number [1] 290306 0

Brief summary
Traumatic disruption of the fibrous sheet between the tibia and fibula in the leg, frequently occurs with a broken ankle, and can result in significant mechanical dysfunction which if untreated, can lead to rapid joint degeneration. Tibio-fibular transfixation using a specially designed (syndesmotic) screw is currently the method of treatment, yet limits normal ankle motion. A new technique called the TightRope, consisting of a fine wire tired to special buttons that anchor onto the bone, offers a new way of providing better stabilization of the ankle, without requiring a second operation. This study aims to compare the accuracy and maintenance of the correct alignment of the tibia and fibula of the two techniques, and the correlation with clinical outcomes and complications. Also, the calculated total cost per injury between these two surgical methods will be analysed. This study will accrue a total of 136 participants who present to the Wellington Regional Hospital with an ankle fracture, and meet inclusion criteria. Following informed consent, participants will be randomized into either surgical intervention utilizing the TightRope procedure, or the cortical screw approach. Both groups will follow an identical post-operative management and rehabilitation programme. The effectiveness of the surgery will be x-ray assessment of the ankle joint, along with clinical outcomes utilizing the American Orthopaedics Foot and Ankle Society Score and the Foot and Ankle Disability Index Score. Range of motion, time to full weight bearing, time to return to work, and rate of complications will also be recorded. Data will then be compared between the two treatment groups. In addition, the total cost for each participant will be calculated to link clinical outcomes to cost-effectiveness.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 44922 0
Dr Logan Walker
Address 44922 0
Wellington Hospital
Riddiford Street
Wellington 6021
Country 44922 0
New Zealand
Phone 44922 0
+64(4) 385 5999
Fax 44922 0
Email 44922 0
Contact person for public queries
Name 44923 0
Dr Logan Walker
Address 44923 0
Wellington Hospital
Riddiford Street
Wellington 6021
Country 44923 0
New Zealand
Phone 44923 0
+64(4) 385 5999
Fax 44923 0
Email 44923 0
Contact person for scientific queries
Name 44924 0
Dr Logan Walker
Address 44924 0
Wellington Hospital
Riddiford Street
Wellington 6021
Country 44924 0
New Zealand
Phone 44924 0
+64(4) 385 5999
Fax 44924 0
Email 44924 0

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