A Noninferiority RCT Comparing Operative vs Nonoperative Treatment for ER-stress Positive Weber-B Unimalleolar Fractures

Study Overview
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Brief Summary
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Current gold standard treatment for unstable (those found unstable in external rotation (ER) stress testing Weber B-type, Lauge-Hansen supination-external rotation type IV) ankle fractures is open reduction and internal fixation (ORIF) with semitubular plates and screws. However, there is some preliminary evidence to suggest that these type of fibula fractures can be managed non-operatively with comparable functional outcome. The aim of this randomized, non-inferiority trial is to assess whether non-operative treatment (cast immobilisation) yields a non-inferior functional outcome compared to surgery with no excess harms (primarily, fracture and wound healing problems and infection).

Detailed Description
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Seventy per cent of ankle fractures are unimalleolar injuries, the Weber B -type of fibula fracture being by far the most common type. The ankle mortise can either be stable or unstable in this type of fracture depending on the accompanying soft tissue injury. The stability of the ankle mortise has fundamental clinical relevance, as it dictates the subsequent treatment strategy. If left untreated, an unstable ankle mortise may lead to fracture healing complications and increased risk of post-traumatic osteoarthritis and subsequently poor functional outcome. Therefore, current clinical practice guidelines recommend surgical treatment for these injuries. The gold standard surgical treatment for unstable ankle fractures is open reduction and internal fixation (ORIF) using 1/3 semi-tubular plates and screws. The most common complication following operative treatment of ankle fracture is wound infection, the incidence ranging from 6.1 to10% in unselected patient materials. To date, there is only one published randomized trial comparing operative and non-operative treatment in patients with an unstable unimalleolar fibula fracture. In this 1-year follow-up, the authors concluded that patients managed nonoperatively had equivalent functional outcomes compared with operative treatment; however, the risk of fracture displacement and problems with union was substantially higher in patients managed nonoperatively. In turn, 10/41 (24%) patients treated operatively were re-operated; five patients had a post-operative infection and five patients required hardware removal. This prospective randomized non-inferiority trial is designed to compare surgical and non-operative treatment of ER-stress positive unimalleolar ankle fractures. The primary, non-inferiority, intention-to-treat outcome is the Olerud-Molander Ankle Score at 104 weeks or 24 months (OMAS; range, 0-100; higher scores indicating better outcome and fewer symptoms). The predefined non-inferiority margin for the primary outcome at the primary assessment time point is 8 points. Secondary outcomes are ankle function, pain, quality of life, ankle range of motion, and radiographic outcome. Follow-up assessments are performed at 2, 6, 12, and 104 weeks (primary time point). Treatment related complications and harms; symptomatic non-unions, loss of congruity of the ankle joint, and wound infections are also recorded. The ER-stress test is performed by a consultant trauma orthopedic surgeon or a trauma resident who has completed trauma rotation. Medial clear space opening of 5 mm or more will be considered a positive ER stress test. Patients are randomized to non-operative or surgical treatment using a sealed envelope method. Surgical treatment is carried out using a standard open reduction and internal fixation with 1/3 semitubular plate and screws. Post-operatively, surgically treated ankles are placed in a below-the-knee cast for six weeks. They are advised to carry out partial weight-bearing (15 to 20 kilograms) for the first four weeks and then weight-bear as tolerated for the remaining two weeks. The non-operative treatment protocol is similar to that of the surgically treated patients: six-week below-the-knee cast with partial weight-bearing for the first four weeks and then weight-bearing as tolerated for the remaining two weeks.

Official Title
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A Prospective Randomized Non-inferiority Trial to Compare Operative Versus Non-operative Treatment for ER-stress Positive Weber-B Unimalleolar Fractures

Conditions
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Lateral Malleolus Fracture

Intervention / Treatment
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* Procedure: Non-operative treatment
* Procedure: Surgery


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Weber B unimalleolar ankle fracture Age: 16 years or older Voluntary Operated within 7 days of the trauma Walking without aid before accident Exclusion Criteria: Peripheral neuropathy Pilon fracture Bilateral ankle fracture Simultaneous crural fracture Pathological fracture Active infection around the ankle A previous ankle fracture or significant medial ligament trauma Lives outside our hospital district or a foreigner Co-operation is insufficient

Ages Eligible for Study
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Minimum Age: 16 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Non-operative<br>Non-operative treatment with six weeks in a below-the-knee cast. Partial weight-bearing (15 to 20 kilograms) for the first four weeks and then weight-bearing as tolerated for the remaining two weeks. | Procedure: Non-operative treatment<br>* Below-the-knee cast for six weeks.<br>|
| Active Comparator: Surgery<br>Open reduction and internal fixation with 1/3 semitubular plate and screws. Post-operatively, surgically treated ankles are placed in a below-the-knee cast for six weeks. They are advised to carry out partial weight-bearing (15 to 20 kilograms) for the first four weeks and then weight-bear as tolerated for the remaining two weeks. | Procedure: Surgery<br>* Open reduction and internal fixation with 1/3 semi-tubular plate and screws.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Olerud-Molander Outcome Score (OMAS) | OMAS; scale from 0 to 100, higher scores indicating better outcomes and fewer symptoms. validated, condition-specific, patient-reported measure of ankle fracture symptoms. | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The Foot and Ankle Outcome Score (FAOS) | FAOS, 5 subscales from 0-100, with higher scores indicating better function | 2 years | 
| RAND 36 Health Item Survey (RAND-36) | For health-related quality-of-life. Eight subscales from 0-100, with higher scores indicating better quality of life | 2 years | 
| a 100 mm Visual Analogue Scale for function and pain (VAS) | Range from 0 to 100, with higher scores indicating more severe pain/dysfunction | 2 years | 
| Fracture healing | Fracture healing is considered complete when the fracture line disappeared and conversely, those fractures with a visible fracture line are deemed non-unions | 2 years | 
| Ankle joint movement | Research physiotherapist measures ankle dorsi- and plantarflexion using a goniometer | 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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ER-stress positive, Unimalleolar fibula fracture, Operative vs non-operative treatment