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Trial registered on ANZCTR

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

Titles & IDs
Public title
Should ankle syndesmosis screws be removed? A randomised, controlled trial.
Scientific title
In patients with syndesmosis screw fixation for ankle fracture diastasis, is removal of the syndesmosis screws at 3 months post surgery more effective than no screw removal in terms of functional outcomes?
Secondary ID [1] 260008 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Ankle fractures requiring syndesmosis screw fixation. 265667 0
Condition category
Condition code
Surgery 265800 265800 0 0
Surgical techniques
Injuries and Accidents 265801 265801 0 0

Study type
Description of intervention(s) / exposure
No removal of ankle syndesmosis screws.
Intervention code [1] 264426 0
Treatment: Surgery
Comparator / control treatment
Removal of ankle syndesmosis screws at three months following fixation surgery.
Control group

Primary outcome [1] 266554 0
Olerud-Molander ankle score (OMAS).
Timepoint [1] 266554 0
Assessments performed at 6 months and 12 months postoperatively.
Secondary outcome [1] 276021 0
American Orthopaedic Foot and Ankle Society (AOFAS) score of hindfoot.
Timepoint [1] 276021 0
Assessments performed at 6 months and 12 months postoperatively.
Secondary outcome [2] 276022 0
Ankle range of motion (measured with goniometer).
Timepoint [2] 276022 0
Assessments performed at 6 months and 12 months postoperatively.
Secondary outcome [3] 276023 0
Radiological loss of reduction.
Timepoint [3] 276023 0
Assessments performed at 6 weeks, 6 months, and 12 months postoperatively.
Secondary outcome [4] 276024 0
Radiological implant failure. Rate of implant failure (e.g. screw breakage or loosening, with or without a second surgery for removal) will be measured for each group. Broken screws will be defined as those in which there is a fracture of the screw. Loosened screws will be defined as those surrounded by a radiolucent zone 1 mm in width extending the length of threads in either the fibula or tibia. For the group randomised for screw removal, the rate of implant failure will only be measured at 6 weeks postoperatively.
Timepoint [4] 276024 0
Assessments performed at 6 weeks, 6 months, and 12 months postoperatively.

Key inclusion criteria
Male or female patients; greater than or equal to 16 years of age; ankle fracture with diastasis for planned syndesmosis screw fixation; AP, lateral and mortise X-ray views of the ankle taken preoperatively; closed fractures; consent form signed.
Minimum age
16 Years
Maximum age
65 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Ankle fractures not requiring syndesmosis screw fixation; compound fractures; pathologic fractures; fracture in a polytraumatised patient; fracture of a bone in the same lower limb (other than ankle fracture complex); patients > 65 years of age; past history of fracture or significant injury or disability of the same ankle; medical conditions too serious for surgery; patients who are unfit to consent; pregnant women.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
All patients with ankle fractures, who fit the inclusion and exclusion criteria, requiring syndesmosis screw fixation will be offered a chance to participate in the study. Following informed patient consent, the principle investigator will be contacted with the patient's details. The principle investigator will randomise the patient into one of the two study groups. Randomisation will not be revealed to the operating surgeons, admitting team, or anyone else involved in patient management. Randomisation will only be revealed following the patient's 6 week postoperative clinic review.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomisation will be performed by a source independent to patient clinical management, and will be concealed from the operating surgeons and admitting team. Randomisation will be performed using a random number generator with restricted blocks. The study will be performed according to an intention-to-treat protocol.
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

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] 3388 0
New Zealand
State/province [1] 3388 0

Funding & Sponsors
Funding source category [1] 264896 0
Self funded/Unfunded
Name [1] 264896 0
Address [1] 264896 0
Country [1] 264896 0
Primary sponsor type
Middlemore Hospital
Private Bag 93311
Auckland 1640
New Zealand
Secondary sponsor category [1] 263996 0
Name [1] 263996 0
Manukau Surgical Centre
Address [1] 263996 0
Private Bag 93311
Auckland 1640
Country [1] 263996 0
New Zealand

Ethics approval
Ethics application status
Ethics committee name [1] 266853 0
New Zealand Health and Disability Ethics Committees
Ethics committee address [1] 266853 0
PO Box 5013
Wellington 6145
Ethics committee country [1] 266853 0
New Zealand
Date submitted for ethics approval [1] 266853 0
Approval date [1] 266853 0
Ethics approval number [1] 266853 0

Brief summary
Screw stabilisation of the disrupted ankle syndesmosis maintains reduction as healing of the distal tibiofibular ligaments occurs. It has previously been thought that syndesmosis screws may contribute to ankle dysfunction by restricting the normal motion between the tibia and fibula. Screw removal, breakage, or loosening may restore motion but can permit loss of reduction if these occur before complete ligamentous healing. As a result, although some well-established principles exist for reduction and surgical treatment of syndesmotic injuries, there remains controversy regarding whether routine syndesmosis screw removal is desirable. We plan to conduct a prospective, randomized, controlled trial to investigate the outcomes of patients with ankle syndesmosis screws left in situ and compare these with the outcomes of patients with removed syndesmosis screws. To date, there have been no randomised, controlled trials comparing these two patient groups.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 32495 0
Dr Matthew J. Boyle
Address 32495 0
Department of Orthopaedics
Middlemore Hospital
Private Bag 93311
Auckland 1640
Country 32495 0
New Zealand
Phone 32495 0
+64 9 276 0000
Fax 32495 0
Email 32495 0
Contact person for public queries
Name 15742 0
Dr Matthew Boyle
Address 15742 0
Department of Orthopaedics
Middlemore Hospital
Private Bag 93311
Auckland 1640
Country 15742 0
New Zealand
Phone 15742 0
64 9 276 0000
Fax 15742 0
Email 15742 0
Contact person for scientific queries
Name 6670 0
Dr Matthew Boyle
Address 6670 0
Department of Orthopaedics
Middlemore Hospital
Private Bag 93311
Auckland 1640
Country 6670 0
New Zealand
Phone 6670 0
64 9 276 0000
Fax 6670 0
Email 6670 0

No information has been provided regarding IPD availability
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