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

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

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).

Study Overview

• Status: Active, not recruiting
• Conditions: Lateral Malleolus Fracture
• Intervention / Treatment: Procedure: Non-operative treatment; Procedure: Surgery

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 126
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Finland
  • Pohjois-Pohjanmaa
    • Oulu, Pohjois-Pohjanmaa, Finland, 90100
      • OYS, Oulu university hospital, Department of orthopedic and traumatology

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

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

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Non-operative; 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; Below-the-knee cast for six weeks.
Active Comparator: Surgery; 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; Open reduction and internal fixation with 1/3 semi-tubular plate and screws.

What is the study measuring?

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

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Talocrural joint congruence	Medial clear space < 4 mm and ≤ 1 mm wider than the superior clear space as measured between the lateral border of the medial malleolus and the medial border of the talus at the level of the talar dome.	At two, six and 12 weeks, and at 2 years

Collaborators and Investigators

• Sponsor: University of Oulu
• Investigators: Principal Investigator: Tero HJ Kortekangas, MD, PhD, Oulu University Hospital; Study Director: Harri J Pakarinen, MD, PhD, Oulu University Hospital

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2013
• Primary Completion (Actual): July 7, 2021
• Study Completion (Estimated): April 1, 2024

Study Registration Dates

• First Submitted: December 26, 2012
• First Submitted That Met QC Criteria: December 31, 2012
• First Posted (Estimated): January 1, 2013

Study Record Updates

• Last Update Posted (Actual): September 14, 2023
• Last Update Submitted That Met QC Criteria: September 13, 2023
• Last Verified: September 1, 2023

More Information

Terms related to this study

• Keywords: ER-stress positive; Unimalleolar fibula fracture; Operative vs non-operative treatment
• Additional Relevant MeSH Terms: Wounds and Injuries; Leg Injuries; Ankle Injuries; Fractures, Bone; Ankle Fractures
• Other Study ID Numbers: OYSrct-Ankle3.2

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Trial data are not publicly available owing to data privacy, but access to the anonymised dataset can be obtained from the corresponding author on reasonable request.

Drug and device information, study documents

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