Functional Orthosis Versus Cast Immobilization for Partially Unstable Weber B Ankle Fractures

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.

Study Overview

• Status: Recruiting
• Conditions: Ankle Fractures
• Intervention / Treatment: Device: Functional orthosis; Device: Cast immobilization

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 Type: Interventional
• Enrollment (Anticipated): 110
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Martin Gregersen; Phone Number: 48171718; Email: martinggregersen@gmail.com

Study Locations

• Norway
  • Gjøvik, Norway
    • Recruiting
    • Sykehuset Innlandet, Gjøvik
    • Contact: Nicolaj Quist Gill; Email: Nicolaj.Emil.Quist.Gill@sykehuset-innlandet.no
    • Contact: Håvard Furunes; Email: havardfurunes@gmail.com
  • Ålesund, Norway
    • Recruiting
    • Alesund Hospital
    • Contact: Ragnhild Justad-Berg; Email: ragnhild.therese.justad-berg@helse-mr.no
    • Contact: Lars Kjetil Aas; Email: Lars.Kjetil.Aas@helse-mr.no
  • Østfold
    • Sarpsborg, Østfold, Norway, 1714
      • Recruiting
      • Østfold Hospital Trust
      • Contact: Martin Greger Gregersen, PhD candidate; Phone Number: +4748171718; Email: martingjohansen@gmail.com
      • Contact: Marius Molund, PhD; Phone Number: +4790093988; Email: marius.molund@so-hf.no

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• 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.

Exclusion Criteria:

• 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).

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: Functional orthosis; 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.	Device: Functional orthosis; See arm descriptions
Active Comparator: Cast immobilization; Use of a below-the-knee cast circular cast (3M scotch cast) for 6 weeks.	Device: Cast immobilization; See arm descriptions

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from 6 weeks Manchester-Oxford Foot and Ankle Questionnaire score at 2 years	Scale 0-100, lower scores indicate less pain and symptoms.	6 weeks, 2 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from 6 weeks Olerud Molander Ankle Score at 2 years	Scale 0-100, higher scores indicate less pain and symptoms.	6 weeks, 2 years
Numeric rating scale of of patient satisfaction with treatment protocol	A 0-10 rating scale for perceived satisfaction with orthosis or cast	6 weeks
Change from baseline tibiotalar congruity at 2 years	Measurement of ankle medial clear space from weightbearing and gravity stress ankle radiographs	Baseline, 2 years
Registrations of complications/adverse events	Registration of possible loss of congruence, delayed union, non-union, thromboembolic events	2 years
Change from 6 weeks ankle range of motion at 2 years	Measurement using a goniometer (ad modum Lindsjø)	6 weeks, 2 years

Collaborators and Investigators

• Sponsor: Ostfold Hospital Trust
• Collaborators: Sykehuset Innlandet HF; Alesund Hospital

Study record dates

Study Major Dates

• Study Start (Actual): May 15, 2022
• Primary Completion (Anticipated): December 31, 2025
• Study Completion (Anticipated): December 31, 2025

Study Registration Dates

• First Submitted: May 6, 2022
• First Submitted That Met QC Criteria: June 7, 2022
• First Posted (Actual): June 9, 2022

Study Record Updates

• Last Update Posted (Estimate): January 30, 2023
• Last Update Submitted That Met QC Criteria: January 27, 2023
• Last Verified: January 1, 2023

More Information

Terms related to this study

• Keywords: Weber B; SER4a
• Additional Relevant MeSH Terms: Wounds and Injuries; Fractures, Bone; Ankle Fractures
• Other Study ID Numbers: 22/00257-3

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

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