Open Reduction Syndesmosis Tightrope Versus Screw Fixation

Tibia-fibular syndesmosis injury occurs in a significant proportion of ankle injuries and is assumed to disrupt the syndesmotic ligaments. The goal of operative treatment is to reduce the ankle mortise to restore normal joint kinematics. Syndesmosis repair can be performed using either open or closed reduction, combined with fixation between the distal tibia and fibula. Closed fixation has demonstrated high rates of non anatomic reductions greater than 40%; therefore, open reduction will be performed in this study. Screw fixation is stable but concerns exist regarding potential excess rigidity.

Recently, flexible fixation techniques combined with anatomic reduction have demonstrated improvements in functional outcomes and reduction quality. Both open reduction and flexible TightRope fixation have considerable support in the literature in cohort studies but have not been compared to open screw fixation in a randomized controlled trial.

This study is a multi centre randomized controlled trial comparing clinical, economic and functional outcomes between open reduction, flexible Tightrope syndesmosis fixation (OT) to open reduction rigid screw fixation (OS) for syndesmotic injuries in high ankle fractures, involving the fibula 1 cm above the level of the syndesmosis (Weber C (OTA 44.C1, 44.C2, 44C3)).

We anticipate recruiting 72 patients (36 in each arm) from up to 20 clinical sites across North America. Post operative follow up will occur at 2 and 6 weeks, 3, 6, and 12 months. At each follow up, radiographic and functional outcomes will be assessed as well as documentation of costs associated with treatment and rehabilitation.

The research questions that this study will answer include the following:

• Does open reduction and repair with TightRope syndesmosis fixation (OT) provide better reduction compared to open reduction and syndesmosis screw fixation (OS)?
• Which surgical technique provides better functional outcomes?
• Are complications and costs associated with repair comparable between surgical techniques?

The null hypothesis is that there will be no difference between the treatment groups in terms of reduction and functional testing.

The scientific aims of this study are to compare:

• anatomic (open) reduction between the two groups using CT scan and plain radiographs.
• post-operative pain and functional performance in each group.
• rates of complications and costs for each method of fixation.

Inclusion criteria

• Male or female 18yrs with a diagnosis of a closed Weber C ankle (OTA 44.C1, 44.C2, 44.C3) fracture.
• Randomization and treatment of syndesmosis injury within 14 days of the date of injury.
• Demonstrates lateral subluxation of talus on x-ray or stress views. Talar shift > 1mm or medial clear space widening ≥ 5mm (unstable)
• No history of previous severe ankle injury, pathologic fracture, ligamentous laxity, no prior diagnosis or current treatment of osteoporosis or metabolic bone disease.
• No concurrent injury that is deemed by the treating surgeon to delay or alter the rehabilitation protocol for the ankle injury.
• No neuromuscular or sensory deficiency.
• Able to understand and complete assessments
• Provision of Informed Consent

Exclusion criteria

• Age < 18 years
• Open fracture or pathological fracture.
• Talar shift < 1mm or medial clear space widening < 5mm (stable)
• Prior diagnosis or current treatment for osteoporosis or metabolic bone disease.
• Concurrent injury that is deemed by the treating surgeon to delay or alter the rehabilitation protocol for the ankle injury.
• Prior diagnosis or treatment for neuromuscular disease or sensory deficiency (i.e. diabetic neuropathy).
• Likely problems, in the judgment of the investigator, with maintaining follow-up (i.e. patients with no fixed address, patients incapable of providing informed consent, prisoners etc.).
• Patients who are currently pregnant or planning to become pregnant during the study duration.