Weber B Ankle Fractures With Associated Posterior Malleolus Fracture (PMFIX)
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ClinicalTrials.gov Identifier: NCT05413707 |
Recruitment Status :
Recruiting
First Posted : June 10, 2022
Last Update Posted : March 15, 2023
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Ankle fractures constitute 9% of all fractures and have an incidence of approximately 187 per 100,000 persons per year in Norway. A posterior malleolar fragment (PMF), located on the lower backside of the tibia, is present in up to 46% of Weber B. Weber B fractures are the most common type of fractures of the fibula, located at the height of the syndesmosis. Patients with a PMF were recently shown to have significantly lower patient-reported outcome measures (PROM) than the general population. For this reason, the indication and choice of intervention for these fractures have been the object of increased interest over the recent years. It is one of the most debated areas within ankle fracture surgery. Traditionally, these PMFs have been treated with closed reduction, without direct manipulation of the PMF, anteroposterior screw fixation, or even no-fixation of the smaller fragments. A more novel posterior approach to the ankle for open reduction and internal fixation is increasingly popular and has led to fixation of smaller and medium-sized PMFs. Studies suggest fracture reduction is better with a posterior approach. However, there is no consensus as to what the best treatment is. There are no available randomized controlled studies examining PROM in patients after surgery with fixation versus no fixation for the PMF.
Through a multicenter prospective randomized controlled trial initiated from Haukeland University Hospital, patients will be recruited and randomized to receive treatment with or without fixation of the PMF. Patients will be recruited at six study hospitals from all Regional Health Trusts in Norway. Treatment today is often based on local tradition and retrospective, ambiguous literature. As there is no clear evidence supporting the choice to fixate, or not fixate, the posterior malleolus fracture. The current study can contribute new knowledge and thereby contribute to an evidence-based approach to treating these patients.
Mason and Molly type 2A and 2B fractures will be included in the study.
Condition or disease | Intervention/treatment | Phase |
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Posterior Malleolus Fractures Ankle Fractures Syndesmotic Injuries Patient Reported Outcome Measure Treatment Outcome | Procedure: Fixation of the posterior malleolus fractures Procedure: Fixation of lateral and/or medial malleolus fractures Procedure: Syndesmotic fixation | Not Applicable |

Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 198 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Intervention Model Description: | Randomized controlled trial with to arms: Fixation of posterior malleolus fractures (PMFs) versus no fixation of the PMF. |
Masking: | None (Open Label) |
Primary Purpose: | Treatment |
Official Title: | Posterior Malleolus Fractures (PMF) in Weber B Ankle Fractures - Fixation Versus no Fixation - a Randomized Controlled Trial |
Actual Study Start Date : | March 13, 2023 |
Estimated Primary Completion Date : | December 31, 2024 |
Estimated Study Completion Date : | December 31, 2029 |

Arm | Intervention/treatment |
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Experimental: Fixation group
Patients are placed in a prone position on the operating table. Fixation of the posterior malleolus fracture. Posterior, and/or lateral and medial malleolus fractures will be treated with open reduction and internal fixation. ORIF of the posteromedial fragment in Mason and Molloy type 2B with one or more screws, or plate, if it is displaced more than 2 mm. Deltoid ligament injuries are repaired if incarcerated between medial malleolus and talus. The posteromedial fragment in Mason and Molloy type 2B will be fixed with one or more screws, or plate, if this fragment is displaced more than 2 mm. A Tillaux-Chaput or Wagstaffe fragment is fixed with suture anchor, plate, screw or pin if displaced >2 mm depending on size and comminution of the fragment. The syndesmosis is tested under fluoroscopy by lateralizing and then externally rotating the talus. If unstable it is fixed with one or two 3.5 mm cortical screws or a suture button. |
Procedure: Fixation of the posterior malleolus fractures
Fixation of the posterior malleolus fracture with screws and or plating. Procedure: Fixation of lateral and/or medial malleolus fractures Fixation with screws and/or plating Procedure: Syndesmotic fixation Fixation of unstable syndesmosis with one or two 3.5 mm tricortical screws, or with a suture button. |
Active Comparator: Non-fixation group
Patients are placed in a supine position on the operating table. No fixation of the PMF. The PMF is reduced by ligamentotaxis. Lateral and/or medial malleolus fractures will be treated with ORIF if present. ORIF of the posteromedial fragment in Mason and Molloy type 2B with one or more screws, or plate, if it is displaced more than 2 mm. Deltoid ligament injuries are repaired if incarcerated between medial malleolus and talus. A Tillaux-Chaput or Wagstaffe fragment is fixed with suture anchor, plate, screw or pin if displaced >2 mm depending on size and comminution of the fragment. The syndesmosis is tested under fluoroscopy by lateralizing and then externally rotating the talus. If unstable it is fixed with one or two 3.5 mm cortical screws or a suturebutton. |
Procedure: Fixation of lateral and/or medial malleolus fractures
Fixation with screws and/or plating Procedure: Syndesmotic fixation Fixation of unstable syndesmosis with one or two 3.5 mm tricortical screws, or with a suture button. |
- Self-Reported Foot and Ankle Score [ Time Frame: 2 years postoperatively ]Foot and ankle specific questionnaire with 12 questions with 5 levels. Total score from 0 (worst) to 48 (best).
- EQ-5D 5L [ Time Frame: Baseline, 6 weeks, 12 weeks, 1 year, 2 years and 5 years postoperatively ]Generic patient reported outcome questionnaire, Presentation of both change from baseline to 12 weeks, 1 year, 2, years and 5 years postoperatively. Presentation of both EQ-5D-5L frequencies and proportions reported by dimension and level, EQ-5D VAS, and EQ-5D index score.
- VAS of stiffness (0-100) [ Time Frame: 6 weeks, 12 weeks, 1 year, 2 years and 5 years postoperatively ]Level of stiffness in the treated ankle from 0 (No stiffness) to 100 (No movement due to stiffness)
- Osteoarthritis [ Time Frame: 2 years and 5 years postoperatively ]Osteoarthritis on plain radiographs at 2- and 5-years postoperative graded by the Kellgren Lawrence classification
- Dorsiflexion [ Time Frame: 6 weeks, 12 weeks, 2 years postoperatively ]
- Dorsiflexion measured by goniometer
o With knee in flexion and the foot on the floor. The patient leans forward as far as possible without the heel lifting. The angle between the floor and the anterior boarder of the tibia is measured with a digital goniometer.
- Change in Self-reported Foot and Ankle Score (SEFAS) [ Time Frame: Baseline, 6 weeks, 12 weeks, 1 year, and 5 years postoperatively ]Foot and ankle specific questionnaire with 12 questions with 5 levels. Total score from 0 (worst) to 48 (best).
- Anchor questions for evaluation of prom [ Time Frame: Baseline (Generic health question). Alle questions: 3 months, 1 year, 2 years and 5 years postoperatively ]Generic and organ specific anchor questions for evaluation of SEFAS results and for patients satisfaction evaluation.

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Ages Eligible for Study: | 18 Years to 65 Years (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Posterior malleolar (PM) fracture, of Mason & Molly type 2A/2B, associated with Weber B lateral malleolar fracture, with or without medial malleolar fracture
- Posterior malleoli >=2 mm displaced (on CT in axial, sagital or coronal plane)
- Patients informed, written consent
- Age 18-65 years
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For inclusion axial CT images are examined
- Measurements are performed 5 millimeters (mm) cranial to the tibia plafond
- Posterior malleolus fractures involving less than 40% of the fibular notch are included.
Exclusion Criteria:
- Non-compliant patient, i.e.: dementia, alcohol- or substance abuse
- ASA-4 patients
- Known congenital bone decease
- Pathological fractures
- Immunocompromised patients
- Tourists or patients on a short-term work/study permit
- Previous injury or condition of the ipsilateral ankle or ipsilateral lower extremity with a resulting dysfunction
- Poor controlled diabetes
- Patients with known arterial insufficiency
- Open fractures
- Severely traumatized patients (ISS>16)
- Patient declines to participate in study

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05413707
Contact: Jostein S Nilsen, MD | 004792226426 | jostein.skorpa.nilsen@helse-bergen.no | |
Contact: Kristian Pilskog, MD | +4798217343 | kpilskog@gmail.com |
Norway | |
Haukeland University Hospital, Orthopedic department | Recruiting |
Bergen, Vestland, Norway, 5021 | |
Contact: Jostein S Nilsen, MD +4792226426 j.skorpa@gmail.com | |
Contact: Kristian Pilskog, MD +4798217343 kpilskog@gmail.com |
Study Director: | Jonas M Fevang, PhD | Helse Bergen, Haukeland University Hospital | |
Principal Investigator: | Jostein S Nilsen, MD | Helse Bergen, Haukeland University Hospital | |
Principal Investigator: | Kristian Pilskog, MD | Helse Bergen, Haukeland University Hospital |
Responsible Party: | Haukeland University Hospital |
ClinicalTrials.gov Identifier: | NCT05413707 |
Other Study ID Numbers: |
255548 |
First Posted: | June 10, 2022 Key Record Dates |
Last Update Posted: | March 15, 2023 |
Last Verified: | January 2023 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
Posterior malleolus fractures Ankle factures Weber B fractures |
Syndesmotic injuries Fixation Randomized Controlled Trial |
Fractures, Bone Ankle Fractures Ankle Injuries Wounds and Injuries Leg Injuries |