Physical Recovery During Bracing After Ankle Fracture (Re-BAF) (Re-BAF)

Physical Recovery During Bracing After Ankle Fracture (Re-BAF): A Multi-Center Superiority Analysis Nested Within a Non-inferiority Randomised Controlled Trial (BAF; NCT07163091)

Ankle fractures are among the most common fractures and represent the second most frequent fracture type requiring surgery. Many patients experience long-term pain, stiffness, and reduced ankle function, which substantially limits their physical activity. Even five years after injury, more than a third of patients have not regained their pre-injury activity levels.

Standard treatment typically involves immobilisation using a rigid foot-ankle brace (walker). Although effective in protecting fracture healing, these braces may be overly restrictive, contributing to ankle stiffness, swelling, delayed physical recovery and return to daily activities, and reduced quality of life. Patients increasingly express a preference for lighter, movement-permitting ankle supports, such as minimal ankle stirrups. Recent evidence suggests that braces and elastic bands that allow more ankle movement than walkers may enhance faster recovery without increasing complications.

However, high quality evidence is necessary for more robust conclusions. The Scandinavian Bracing after Ankle Fracture (BAF) multicentre randomised controlled trial (NCT07163091) therefore investigates whether an ankle stirrup is non-inferior to a standard walker with respect to patient-reported ankle pain and function, measured by the Manchester-Oxford Foot Questionnaire (MOXFQ) three months after ankle fracture. The primary hypothesis is that ankle stirrups better align with patients' preferences for less restrictive bracing while providing sufficient stability during fracture healing. Secondarily, ankle stirrups may promote faster recovery and physical activity.

The Re-BAF trial is nested within a larger multicentre non-inferiority trial (Bracing after Ankle Fracture [BAF], ClinicalTrials.gov ID: NCT07163091), aiming to investigate whether an ankle stirrup is non-inferior to a standard foot-ankle brace in improving patient-reported foot and ankle function, as measured by the Manchester-Oxford Foot Questionnaire ([MOXFQ], primary BAF outcome) after ankle fracture.

The aim of the Re-BAF trial is to investigate whether ankle stirrups are superior to standard foot-ankle braces in improving physical activity, assessed using objectively measured thigh-worn accelerometry from baseline (i.e. randomisation) to 12-week follow-up. We hypothesize that early and continuous movement during rehabilitation, enabled by an ankle stirrup, is superior in improving physical activity compared with a foot-ankle brace, without compromising fracture healing.

Study Overview

• Status: Not yet recruiting
• Conditions: Physical Activity; Rehabilitation; Recovery; Ankle Fracture
• Intervention / Treatment: Other: Ankle stirrup; Other: Foot-ankle brace

Detailed Description

Background: Although patients generally acknowledge the need for immobilisation following ankle fracture, a qualitative study including ten patients found substantial challenges in adhering to immobilisation recommendations. In a randomised controlled trial (RCT) by Smeeing et al. (2020), braces and elastic bandages permitting greater ankle movement than standard walkers were not associated with poorer functional outcomes and were associated with a faster return to work (p = 0.02) without an increased risk of complications. However, the trial was terminated after inclusion of only half of the planned sample, raising concerns regarding statistical power and robustness of the findings. Compared to the walker, ankle stirrups may better align with patient preferences while promoting physical activity and faster recovery.

Aim: The aim of this Re-BAF trial is to investigate if ankle stirrups, allowing active weight-bearing, are superior to rigid foot-ankle braces on patients' daily physical activity levels and physical recovery.

Study design: Superiority trial including 280 adult patients (140 per arm) with surgically or non-surgically treated ankle fractures, nested within a larger Scandinavian randomized multicentre non-inferiority trial (n=1400). Participants will be randomized to four weeks of weight-bearing as tolerated in either an ankle stirrup or a foot-ankle brace.

Eligibility: Inclusion: patients aged ≥18 years with surgically or non-surgically treated ankle fractures. Exclusion: pathological fractures, open fractures, prolonged need for ankle immobilisation (e.g., non-union or poor wound healing), inability to adhere to trial procedures (e.g. neuropathy or severe psychiatric disorder), non-weight bearing treatment, allergy to adhesive tape used for the SENS apparatus, uninterest in participating in the trial, or inability to read Danish.

Recruitment: Patients will be recruited at their one- to two-week follow-up from orthopaedic departments across Denmark. Patient recruitment begins after one to two weeks, as surgically treated patients are typically immobilised in casts or foot-ankle braces and instructed to avoid or minimise weight-bearing during the initial postoperative period to allow swelling to subside and wounds to heal. Likewise, non-surgically treated patients are typically immobilised in a foot-ankle brace. However, weight-bearing recommendations vary between hospitals and surgeons, ranging from weight-bearing as tolerated to limited or non-weight-bearing until fracture stability is confirmed radiographically at the one- to two-week follow-up. The type of immobilisation (e.g., cast or brace) and weight-bearing restrictions during the initial weeks therefore vary across hospitals and treating surgeons.

Randomisation: Patients will be randomised to four weeks of weight-bearing as tolerated in either a foot-ankle brace (walker) or an ankle stirrup, using REDCap Randomize, allocated 1:1. Randomisation will be performed in blocks to ensure balanced allocation of surgically and non-surgically treated patients between groups, as well as equal distribution of intervention and control patients across recruitment centres. Weight-bearing will be unrestricted in both groups; thus, the only intervention difference will be the type of brace (ankle stirrup versus walker). Other variation will reflect usual clinical practice.

Methods: From baseline (randomisation), patients will wear a thigh-worn SENS Motion® accelerometer, a GDPR-compliant medical sensor that continuously records physical activity, movement intensity, and nocturnal activity. The device will be worn until the battery is depleted, which is expected to occur after approximately 20 weeks. Weekly surveys will capture pain, analgesic use, and fear of movement. Additionally, two questionnaires will be distributed electronically via e-Boks alongside the patient-reported outcome measures (PROMs) of the BAF trial to assess fear of movement and patient-reported physical activity.

Outcomes: The primary outcome is the between-group difference in total physical activity (accelerometer counts) from baseline (randomisation) to 12 weeks post-fracture, while secondary outcomes include between-group differences in daily step counts, nocturnal activity (sleep efficiency proxy), time to resume vigorous activities, pain, analgesic use, patient-reported physical activity, and fear of movement.

A detailed and pre-specified Statistical Analysis Plan (SAP) will be made publicly available prior to database lock and before any unblinding of the data.

Timepoints: Assessments will be performed at baseline (randomisation), 6 weeks, 12 weeks (primary endpoint). Accelerometer-based measurements and weekly surveys will continue until the battery of the SENS accelerometer is depleted (approximately 22 weeks post-fracture). Questionnaires will be collected at 6, 12, and 26 weeks post-fracture alongside the patient-reported outcome measures of the BAF trial.

Sample size calculation: As no anchor-based minimal clinically important difference (MCID) exists for physical activity in ankle fracture patients, an MCID of 17-35% in daily step counts, derived from research on chronic obstructive pulmonary disease, will be used. Applying a 17% threshold to total accelerometer counts per day, on a comparable patient group, results in an expected between-group difference of 50,500 activity counts/day. To detect statistically significant differences at a two-tailed α level of 0.05 and β = 0.80, assuming a standard deviation of 101,000 counts per day before and after the intervention, a sample of 63 participants from each subgroup (surgical/non-surgical) per intervention group (ankle stirrup vs. foot-ankle brace) is required. To account for potential dropouts, seven additional patients will be included per subgroup, resulting in a total sample size of 280 patients.

Blinding/masking: Participants and care providers cannot be blinded due to the nature of the brace interventions. Data are labelled using allocation codes only. Outcome assessments and statistical analyses will be performed blinded to treatment allocation. The primary investigator is not involved in the randomisation process and will remain blinded to allocation during data collection, management and analysis.

• Study Type: Interventional
• Enrollment (Estimated): 280
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Katrine K Krag-Andersen, PT, MSc; Phone Number: +4522466435; Email: kanderse@health.sdu.dk
• Study Contact Backup: Name: Jonas A Ipsen, PT, PhD; Phone Number: +4523925264; Email: Jonas.Ammundsen.Ipsen@rsyd.dk

Study Locations

• Denmark
  • Region Syddanmark
    • Odense, Region Syddanmark, Denmark, 5000
      • Odense University Hospital
      • Contact: Bjarke Viberg, MD, PhD; Phone Number: +4528669059; Email: bjarke.viberg@rsyd.dk
      • Contact: Louise D Petersen, Clinical Research Coordinator; Phone Number: +45 51435711; Email: Louise.Dyhring.Petersen@rsyd.dk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• 18 years or older
• Surgically or non-surgically treated ankle fracture

Exclusion Criteria:

• Pathological fractures
• Open fractures (skin perforation)
• Prolonged need for immobilisation (e.g. non-union or insufficient wound healing)
• Non-weight bearing treatment
• Inability to adhere to trial procedures (e.g. neuropathy or severe psychiatric disorder)
• Allergy to SENS Motion adhesive patches
• Inability to read or speak Danish
• Uninterest in participating

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Ankle stirrup; Active ankel dorsal and plantar flexion during use of the ankle stirrup	Other: Ankle stirrup; Four weeks of weight-bearing as tolerated using an ankle stirrup
Active Comparator: Foot-ankle brace (walker); Immobilisation during use of the foot-ankle brace	Other: Foot-ankle brace; Four weeks of weight-bearing as tolerated using a foot-ankle brace (walker)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Daily SENS Motion® accelerometer counts as a measure of daily physical activity during the first 12 weeks following ankle fracture	From baseline (randomisation) until 12 weeks post-fracture, participants will continuously wear a thigh-mounted SENS Motion® accelerometer, a GDPR-compliant medical-grade sensor, to objectively assess physical activity and sleep. The SENS Motion accelerometer is a validated device for use in both younger and older orthopaedic populations. It continuously measures total physical activity (expressed as accelerometer counts per day), time spent resting, standing, and being physically active (including walking, running, and cycling), number of steps, movement intensity, nocturnal activity, and sleep duration. The primary endpoint is the between-group difference in physical activity (accelerometer counts) from baseline (randomisation) to 6 and 12 weeks (primary) post-fracture.	From baseline (randomisation) to 12 weeks post-fracture.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Weekly minutes of moderate-to-vigorous-intensity physical activity (MVPA) in the first 12 weeks following ankle fracture	Between-group differences in weekly minutes of moderate-to-vigorous physical activity (MVPA), derived from accelerometer-based activity measurements.	From baseline (randomisation) to 6 weeks and 12 weeks post-fracture
Patient-reported physical activity during the first 12 weeks post-fracture	Between-group differences in self-reported physical activity level will be assessed using the short-form International Physical Activity Questionnaire (IPAQ-SF). The IPAQ-SF assesses self-reported physical activity over the previous seven days and summarises walking, moderate-intensity activity, vigorous-intensity activity, and sitting time into a single score expressed as metabolic equivalent minutes per week (MET-min/week). This summary score is subsequently used to classify patients into one of three physical activity levels: low, moderate, or high. Only this categorical classification will be used as the outcome measure. The questionnaire will be distributed electronically via e-Boks at baseline (randomisation) and at 6 and 12 weeks post-fracture, alongside the PROMs from the BAF trial, within which Re-BAF is nested.	Between-group differences are evaluated from baseline (randomisation) to 6 weeks and 12 weeks post-fracture
Patient-reported weekly pain during the first 12 weeks post-fracture	Between-group differences in patient-reported pain intensity will be assessed using the Numeric Rating Scale (NRS). The NRS is an 11-point scale ranging from 0 (no pain) to 10 (worst imaginable pain), on which patients report their average pain intensity over the past week. Assessments will be collected weekly via an app-based survey.	Between-group differences over time from baseline (randomisation) to 12 weeks post-fracture will be analysed using mixed-effects models with repeated weekly measurements, with results reported at 6 and 12 weeks.
Patient-reported weekly analgesic use during the first 12 weeks post-fracture	Between-group differences in patient-reported analgesic use will be assessed using a single-item measure capturing the number of days (0-7) on which analgesics were taken during the previous 7 days. Assessments will be collected weekly via an app-based survey.	Between-group differences over time from baseline (randomisation) to 12 weeks post-fracture will be analysed using mixed-effects models with repeated weekly measurements, with results reported at 6 and 12 weeks.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Daily SENS Motion® accelerometer counts as a measure of daily physical activity at longer-term follow-up (12-22 weeks post-fracture)	From week 12 and until battery is depleted (approximately 22 weeks post-fracture), participants will continuously wear a thigh-mounted SENS Motion® accelerometer, a GDPR-compliant medical-grade sensor, to objectively assess physical activity and sleep. The SENS Motion accelerometer is a validated device for use in both younger and older orthopaedic populations. It continuously measures total physical activity (expressed as accelerometer counts per day), time spent resting, standing, and being physically active (including walking, running, and cycling), number of steps, movement intensity, nocturnal activity, and sleep duration. Secondary outcomes include between-group differences of daily accelerometer counts from baseline (randomisation) to 6 weeks (bracing period) and to 22 weeks (subacute recovery phase) post-fracture.	From 12 to 22 weeks post-fracture.
Adherence to the WHO Physical Activity Guidelines	Between-group differences in the proportion of participants adhering to the World Health Organization (WHO) physical activity guidelines, determined using objectively measured accelerometer data (daily/weekly accelerometer counts)	From baseline (randomisation) to 6 weeks, 12 weeks, and 22 weeks post-fracture.
Weekly minutes of moderate-to-vigorous physical activity (MVPA) at longer-term follow-up (12-22 weeks post-fracture)	Between-group differences in weekly minutes of moderate-to-vigorous physical activity (MVPA), derived from accelerometer-based activity measurements.	From 12 to 22 weeks post-fracture.
Sleep efficiency objectively measured using SENS Motion® accelerometer data at shorter-term (<12 weeks) and longer-term (12-22 weeks) post-fracture	Between-group differences in sleep efficiency, assessed using accelerometer-derived measures of nocturnal activity and sleep duration.	From baseline (randomisation) to 6 weeks, 12 weeks, and 22 weeks post-fracture.
Patient-reported pain at longer-term follow-up (12-22 weeks post-fracture)	Between-group differences in patient-reported pain intensity, assessed using the Numeric Rating Scale (NRS). The NRS is an 11-point scale ranging from 0 (no pain) to 10 (worst imaginable pain), where participants report their average pain intensity during the previous week. Assessments will be collected weekly via an app-based survey from week 12 to 22 post-fracture.	Assessed weekly from 12 to 22 weeks post-fracture. Between-group differences will be evaluated from 12 to 22 weeks post-fracture.
Patient-reported weekly analgesic use at longer-term follow-up (12-22 weeks post-fracture)	Between-group differences in patient-reported analgesic use will be assessed using a single-item measure capturing the number of days (0-7) on which analgesics were taken during the previous 7 days. Assessments will be collected weekly via an app-based survey.	Assessed weekly from 12 to 22 weeks post-fracture. Between-group differences will be evaluated from 12 to 22 weeks post-fracture.
Fear of Movement (TSK-13) at shorter-term (<12 weeks) and longer-term (12-26 weeks) post-fracture	Between-group differences in patient-reported fear of movement (kinesiophobia), assessed using the Tampa Scale for Kinesiophobia (TSK-13). The TSK-13 is a 13-item validated patient-reported outcome measure assessing fear of movement and (re)injury. The questionnaire will be distributed electronically via e-Boks at baseline and at 6 weeks, 12 weeks, and 26 weeks post-fracture, together with the PROMs from the BAF trial, within which Re-BAF is nested.	From baseline (randomisation) to 6 weeks, 12 weeks, and 26 weeks post-fracture.
Perceived foot- and ankle confidence at shorter-term (<12 weeks) and longer-term (12-22 weeks) post-fracture	Between-group differences in weekly patient-reported confidence in foot and ankle function, assessed using a single item from the Foot and Ankle Outcome Score (FAOS). The item used is: "How much are you troubled by lack of confidence in your foot/ankle?", answered on a 0-4 Likert scale. The FAOS is a Danish validated, region-specific patient-reported outcome measure assessing patients' perceived foot- and ankle-related symptoms, function, and confidence. Assessments will be collected weekly via an app-based survey.	Assessed weekly from baseline (randomisation) until 22 weeks post-fracture. Between-group differences are evaluated from baseline (randomisation) to 6 weeks, 12 weeks, and 22 weeks post-fracture.
Patient-reported physical activity at longer-term (12-26 weeks) post-fracture	Between-group differences in self-reported physical activity level will be assessed using the short-form International Physical Activity Questionnaire (IPAQ-SF). The IPAQ-SF assesses self-reported physical activity over the previous seven days and summarises walking, moderate-intensity activity, vigorous-intensity activity, and sitting time into a single score expressed as metabolic equivalent minutes per week (MET-min/week). This summary score is subsequently used to classify patients into one of three physical activity levels: low, moderate, or high. Only this categorical classification will be used as the outcome measure. The questionnaire will be distributed electronically via e-Boks at baseline (randomisation) and at 12 weeks and 26 weeks post-fracture, alongside the PROMs from the BAF trial, within which Re-BAF is nested.	Between-group differences will be evaluated from 12 to 26 weeks post-fracture
Perceived activity limitation at shorter-term (<12 weeks) and longer-term (12-22 weeks) post-fracture	Between-group differences in weekly patient-reported limitation in performing physical activity, assessed using a single-item question. Patients are asked: "To what extent do you feel limited in performing physical activity?", with response options on a 5-point Likert scale ranging from "Not at all" to "To a very high degree". Assessments will be collected weekly via an app-based survey.	Assessed weekly from baseline (randomisation) until 22 weeks post-fracture. Between-group differences are evaluated from baseline (randomisation) to 6 weeks, 12 weeks, and 22 weeks post-fracture.

Collaborators and Investigators

• Sponsor: Odense University Hospital
• Collaborators: Zealand University Hospital; Aarhus University Hospital; Sygehus Lillebaelt
• Investigators: Study Chair: Anders Holsgaard-Larsen, PhD, Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Denmark, and Department of Clinical Research, University of Southern Denmark, Denmark.

Publications and helpful links

General Publications

• Somersalo A, Paloneva J, Kautiainen H, Lonnroos E, Heinanen M, Kiviranta I. Incidence of fractures requiring inpatient care. Acta Orthop. 2014 Sep;85(5):525-30. doi: 10.3109/17453674.2014.908340. Epub 2014 Apr 3.
• Smeeing DP, Houwert RM, Briet JP, Kelder JC, Segers MJ, Verleisdonk EJ, Leenen LP, Hietbrink F. Weight-bearing and mobilization in the postoperative care of ankle fractures: a systematic review and meta-analysis of randomized controlled trials and cohort studies. PLoS One. 2015 Feb 19;10(2):e0118320. doi: 10.1371/journal.pone.0118320. eCollection 2015.
• Smeeing DPJ, Houwert RM, Briet JP, Groenwold RHH, Lansink KWW, Leenen LPH, van der Zwaal P, Hoogendoorn JM, van Heijl M, Verleisdonk EJ, Segers MJM, Hietbrink F. Weight-bearing or non-weight-bearing after surgical treatment of ankle fractures: a multicenter randomized controlled trial. Eur J Trauma Emerg Surg. 2020 Feb;46(1):121-130. doi: 10.1007/s00068-018-1016-6. Epub 2018 Sep 24.
• Michael Möller CE, Cecilia Mellstrand Navarro, Cecilia Rogmark, Emilia Möller Rydberg, Fabian Burmeister, Hans Juto, Hans-Peter Bögl, Jonas Sundkvist, Mattias Lorentzon, Michael Möller,Mikael Sundfeldt, My von Friesendorff, Olof Wolf, Paul Gerdhem, Morberg, Torsten Backteman, Sebastian Mukka, Simon Blixt Hanne Carlsen. Svenska Frakturregistret Årsrapport 2022. Valentin Experience Regiontryckeriet VGR: Svenska Frakturregistret; 2022.
• Tengberg P.T BM, Gromov K, Kallemose T, Troelsen A. Annual Report Danish Fracture Database 2017.
• Zinder SM, Granata KP, Shultz SJ, Gansneder BM. Ankle bracing and the neuromuscular factors influencing joint stiffness. J Athl Train. 2009 Jul-Aug;44(4):363-9. doi: 10.4085/1062-6050-44.4.363.
• Luna IE, Kehlet H, Wede HR, Hoevsgaard SJ, Aasvang EK. Objectively measured early physical activity after total hip or knee arthroplasty. J Clin Monit Comput. 2019 Jun;33(3):509-522. doi: 10.1007/s10877-018-0185-5. Epub 2018 Jul 23.
• Teylan M, Kantorowski A, Homsy D, Kadri R, Richardson C, Moy M. Physical activity in COPD: Minimal clinically important difference for medical events. Chron Respir Dis. 2019 Jan-Dec;16:1479973118816424. doi: 10.1177/1479973118816424.
• McKeown R, Kearney RS, Liew ZH, Ellard DR. Patient experiences of an ankle fracture and the most important factors in their recovery: a qualitative interview study. BMJ Open. 2020 Feb 4;10(2):e033539. doi: 10.1136/bmjopen-2019-033539.
• Appell HJ. Muscular atrophy following immobilisation. A review. Sports Med. 1990 Jul;10(1):42-58. doi: 10.2165/00007256-199010010-00005.
• Ribeiro de Avila V, Bento T, Gomes W, Leitao J, Fortuna de Sousa N. Functional Outcomes and Quality of Life After Ankle Fracture Surgically Treated: A Systematic Review. J Sport Rehabil. 2018 May 1;27(3):274-283. doi: 10.1123/jsr.2016-0199. Epub 2018 Jun 1.
• Kelemework AD, Haile AW, Bayable SD. Assessing the functional outcomes of ankle fracture and its predictive factors following surgical treatment at Addis Ababa burn, emergency, and trauma (AaBET) hospital, Addis Ababa, Ethiopia, 2021: A 5-year retrospective cross-sectional study. Eur J Orthop Surg Traumatol. 2023 Apr;33(3):661-667. doi: 10.1007/s00590-022-03283-2. Epub 2022 Jun 6.
• Shah NH, Sundaram RO, Velusamy A, Braithwaite IJ. Five-year functional outcome analysis of ankle fracture fixation. Injury. 2007 Nov;38(11):1308-12. doi: 10.1016/j.injury.2007.06.002. Epub 2007 Sep 20.

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2026
• Primary Completion (Estimated): September 30, 2028
• Study Completion (Estimated): September 30, 2029

Study Registration Dates

• First Submitted: March 20, 2026
• First Submitted That Met QC Criteria: April 7, 2026
• First Posted (Actual): April 13, 2026

Study Record Updates

• Last Update Posted (Actual): April 13, 2026
• Last Update Submitted That Met QC Criteria: April 7, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Rehabilitation; Recovery; Physical activity; Randomized Controlled Trial; Ankle Fractures; Braces
• Additional Relevant MeSH Terms: Wounds and Injuries; Leg Injuries; Fractures, Bone; Ankle Injuries; Behavior; Ankle Fractures; Motor Activity
• Other Study ID Numbers: VMK: 2502110; 10.46540/4308-00191B (Other Grant/Funding Number: Independent research fund Denmark); 2025 - A6961 (Other Grant/Funding Number: OUH PhD Fund)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Access to individual de-identified participant data will be provided to anyone who wishes to access the data.
• IPD Sharing Time Frame: Immediately following publication, no end date.
• IPD Sharing Access Criteria: Any researcher, affiliated to an established institution
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No