Ankle FracturesNCT05412693
Functional Orthosis Versus Cast Immobilization for Partially Unstable Weber B Ankle Fractures
A study testing Functional orthosis and Cast immobilization in people with Ankle Fractures, run by Ostfold Hospital Trust at 3 sites in Norway.
Trial summary
Stability dictates treatment choice for trans-syndesmotic fibula fractures. Optimal treatment for partially unstable fractures remains a topic of debate. The purpose of this study is to evaluate possible outcome non-inferior of functional orthosis treatment versus cast immobilization for these fractures. Read more about this study
- Who is it for?
- Ages 18 to 80 years
- Conditions the study is for
- Ankle Fractures
- What is being tested?
- Functional orthosis and Cast immobilization
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 115 participants
- Where
- 3 sitesNorway
- Study dates
- 15 May 2022to 30 Mar 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients:
- With isolated Weber type B fractures that are deemed stable on weightbearing radiographs (MCS injured ankle - MCS uninjured ankle < 1 mm).
- With concomitant gravity stress test evaluated as unstable (MCS injured ankle - MCS uninjured ankle < 1 mm)
- Presenting to one of the participating hospitals, and that are available for stability evaluation within 14 days after injury.
- 18-80 years of age
- With pre-injury walking ability without aids.
Who cannot join
- Patients:
- with fracture of the medial malleolus, pre-hospital closed fracture reduction, open fracture, fracture resulting from high-energy trauma or multi-trauma or pathologic fracture.
- with fracture of the posterior malleolus involving 25% or more of the joint surface or with a step of the intraarticular surface. (non-displaced fractures smaller than 25% can be included)
- with neuropathies and generalized joint disease such as Rheumatoid Arthritis.
- that are assumed not compliant (drug use, cognitive- and/or psychiatric disorders).
- with previous history of ipsilateral ankle fracture.
- with previous history of ipsilateral major ankle-/foot surgery.
- who live outside one of the participating hospitals catchment areas (not available for follow-up).
Trial locations and contacts
3 sites in 1 country.
Norway3 sites
Ålesund Hospital
Ålesund
Sykehuset Innlandet, Gjøvik
Gjøvik
Østfold Hospital Trust
Sarpsborg, Østfold fylke, 1714
About this study
Official title: Six Weeks Functional Orthosis Versus Cast Immobilization for Partially Unstable Weber B/SER4a Ankle Fractures - a Multicenter Randomized Non-inferiority Trial
Stability dictates treatment choice for trans-syndesmotic fibula fractures. Optimal treatment for partially unstable fractures remains a topic of debate. The purpose of this study is to evaluate possible outcome non-inferior of functional orthosis treatment versus cast immobilization for these fractures.
Read the detailed description
Evidence suggests that Weber B ankle fractures should be treated nonoperatively if the ankle mortise is stable. Stability is maintained if the deltoid ligament is intact, also known as a Weber B/SER2 injury. Functional orthosis treatment is advised for these injuries. Recently, authors have demonstrated that the fractured ankle can be functionally stable even with a partial deltoid ligament injury. Our interpretation of a partial deltoid ligament injury is when weightbearing radiographs indicate stability (no increase in medial clear space), while concomitant gravity stress radiographs indicate instability (due to increase in medial clear space). It is suggested that this is referred to as a Weber B/SER4a injury. Although now considered for nonoperative treatment, partially unstable/SER4a injuries were traditionally treated operatively. Today, the superiority of one method of nonoperative treatment over another for partially unstable/SER4a injuries remains unclear. Some authors advocate cast immobilization while others have shown good outcomes after inconsistently using different orthoses and cast devices. The argument for cast immobilization appears to be a fear of posttraumatic osteoarthritis because of potential recurrent instability. As a result, cast immobilization of partially unstable/SER4a fractures is implemented in reference European guidelines, and thus must be considered the reference treatment. To our knowledge, no study has documented increased prevalence of osteoarthritis associated with functional treatment of partially unstable/SER4a fractures. The use of cast immobilization remains a precautionary principle, but the choice is not so clear cut because cast immobilization comes with an increased risk of joint stiffness and thromboembolic complications. Long-term radiographic and patient-reported outcome data evaluating possible non-inferiority of functional orthosis treatment compared to cast immobilization will assist in guiding future treatment strategies of these common fractures.
- Conditions
- Ankle Fractures
- Being tested
- Functional orthosis, Cast immobilization
- Keywords
- Weber B, SER4a
- Medical subject headings
- Ankle Fractures
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Functional orthosisDevice
See arm descriptions
Cast immobilizationDevice
See arm descriptions
| Study group | Role | What they receive |
|---|---|---|
| Functional orthosis | Experimental | Use of a functional orthosis device (AirCast Air-Stirrup) for 6 weeks. Weightbearing as tolerated will be allowed in both groups immediately after application of the cast or orthosis. Receives: Device: Functional orthosis |
| Cast immobilization | Active comparator | Use of a below-the-knee cast circular cast (3M scotch cast) for 6 weeks. Receives: Device: Cast immobilization |
What is being measured
The primary outcome is the main question the study is designed to answer.
Between-groups difference in Manchester-Oxford Foot and Ankle Questionnaire score at 2 years
Scale 0-100, lower scores indicate less pain and symptoms.
Measured: 2 years
Secondary outcomes (5)
Between-groups difference in Olerud Molander Ankle Score at 2 years
Scale 0-100, higher scores indicate less pain and symptoms.
Measured: 2 years
Numeric rating scale of of patient satisfaction with treatment protocol
A 0-10 rating scale for perceived satisfaction with orthosis or cast
Measured: 6 weeks
Tibiotalar congruity comparing injured and uninjured ankle at 2 years
Measurement of ankle medial clear space from weightbearing and gravity stress ankle radiographs
Measured: 2 years
Registrations of complications/adverse events
Registration of possible loss of congruence, delayed union, non-union, thromboembolic events
Measured: 2 years
Change from 6 weeks ankle range of motion at 2 years
Measurement using a goniometer (ad modum Lindsjø)
Measured: 6 weeks, 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Jun 2022
- Study start15 May 2022
- Primary completion30 Mar 2026
- Study completion30 Mar 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Ankle FracturesStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Investigator, Outcomes assessor
- Enrolment
- 115 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ostfold Hospital Trust
- Sponsor type
- University, hospital or other
- Collaborators
- Alesund Hospital, Sykehuset Innlandet HF
- Responsible party
- Principal investigator, Marius Molund, Ostfold Hospital Trust
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05412693
- Sponsor's protocol ID
- 22/00257-3
- Status last verified
- Jul 2026
- First submitted
- 6 May 2022
- Last updated
- 24 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 24 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Six Weeks Functional Orthosis Versus Cast Immobilization for Partially Unstable Weber B/SER4a Ankle Fractures - a Multicenter Randomized Non-inferiority Trial
- ClinicalTrials.gov ID
- NCT05412693
- Acronym / sponsor ID
- 22/00257-3
- Conditions
- Ankle Fractures
- Keywords
- Weber B, SER4a
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 115 participants (actual)
- Lead sponsor
- Ostfold Hospital TrustUniversity, hospital or other
- Collaborators
- Alesund Hospital, Sykehuset Innlandet HF
- Study start
- 15 May 2022 (actual)
- Primary completion
- 30 Mar 2026 (actual)
- Study completion
- 30 Mar 2026 (actual)
- First posted
- 9 Jun 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Stability dictates treatment choice for trans-syndesmotic fibula fractures. Optimal treatment for partially unstable fractures remains a topic of debate. The purpose of this study is to evaluate possible outcome non-inferior of functional orthosis treatment versus cast immobilization for these fractures.
Detailed description
Evidence suggests that Weber B ankle fractures should be treated nonoperatively if the ankle mortise is stable. Stability is maintained if the deltoid ligament is intact, also known as a Weber B/SER2 injury. Functional orthosis treatment is advised for these injuries. Recently, authors have demonstrated that the fractured ankle can be functionally stable even with a partial deltoid ligament injury. Our interpretation of a partial deltoid ligament injury is when weightbearing radiographs indicate stability (no increase in medial clear space), while concomitant gravity stress radiographs indicate instability (due to increase in medial clear space). It is suggested that this is referred to as a Weber B/SER4a injury. Although now considered for nonoperative treatment, partially unstable/SER4a injuries were traditionally treated operatively. Today, the superiority of one method of nonoperative treatment over another for partially unstable/SER4a injuries remains unclear. Some authors advocate cast immobilization while others have shown good outcomes after inconsistently using different orthoses and cast devices. The argument for cast immobilization appears to be a fear of posttraumatic osteoarthritis because of potential recurrent instability. As a result, cast immobilization of partially unstable/SER4a fractures is implemented in reference European guidelines, and thus must be considered the reference treatment. To our knowledge, no study has documented increased prevalence of osteoarthritis associated with functional treatment of partially unstable/SER4a fractures. The use of cast immobilization remains a precautionary principle, but the choice is not so clear cut because cast immobilization comes with an increased risk of joint stiffness and thromboembolic complications. Long-term radiographic and patient-reported outcome data evaluating possible non-inferiority of functional orthosis treatment compared to cast immobilization will assist in guiding future treatment strategies of these common fractures.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Functional orthosis | Experimental | Device: Functional orthosisUse of a functional orthosis device (AirCast Air-Stirrup) for 6 weeks. Weightbearing as tolerated will be allowed in both groups immediately after application of the cast or orthosis. |
| Cast immobilization | Active comparator | Device: Cast immobilizationUse of a below-the-knee cast circular cast (3M scotch cast) for 6 weeks. |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Patients:
- With isolated Weber type B fractures that are deemed stable on weightbearing radiographs (MCS injured ankle - MCS uninjured ankle < 1 mm).
- With concomitant gravity stress test evaluated as unstable (MCS injured ankle - MCS uninjured ankle < 1 mm)
- Presenting to one of the participating hospitals, and that are available for stability evaluation within 14 days after injury.
- 18-80 years of age
Key exclusion criteria (8 listed)
- Patients:
- with fracture of the medial malleolus, pre-hospital closed fracture reduction, open fracture, fracture resulting from high-energy trauma or multi-trauma or pathologic fracture.
- with fracture of the posterior malleolus involving 25% or more of the joint surface or with a step of the intraarticular surface. (non-displaced fractures smaller than 25% can be included)
- with neuropathies and generalized joint disease such as Rheumatoid Arthritis.
- that are assumed not compliant (drug use, cognitive- and/or psychiatric disorders).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Functional orthosisSee arm descriptions | Device | Functional orthosis |
| Cast immobilizationSee arm descriptions | Device | Cast immobilization |
Primary outcome
Between-groups difference in Manchester-Oxford Foot and Ankle Questionnaire score at 2 years
Time frame: 2 years
Scale 0-100, lower scores indicate less pain and symptoms.
5 secondary outcomes
Between-groups difference in Olerud Molander Ankle Score at 2 years
Time frame: 2 years
Numeric rating scale of of patient satisfaction with treatment protocol
Time frame: 6 weeks
Tibiotalar congruity comparing injured and uninjured ankle at 2 years
Time frame: 2 years
Registrations of complications/adverse events
Time frame: 2 years
Change from 6 weeks ankle range of motion at 2 years
Time frame: 6 weeks, 2 years
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Jul 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Functional orthosis and Cast immobilization in people with Ankle Fractures, run by Ostfold Hospital Trust at 3 sites in Norway.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 24 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in Norway. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Between-groups difference in Manchester-Oxford Foot and Ankle Questionnaire score at 2 years (time frame: 2 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Jul 2026.