Syndesmotic Screw Vs Suture Button in Ankle Syndesmotic Diastasis

The term syndesmotic injury is used to describe a lesion of the ligaments that connect the distal fibula and the tibial notch surrounded on both sides by the anterior and posterior tibial tubercles, with or without an associated injury of the deltoid ligament.

Accuracy and maintenance of syndesmosis reduction are considered the key elements in the treatment of ankle fractures. Screw fixation is considered the gold standard treatment for an unstable syndesmosis injury.

Button and suture construction with a medial-lateral metallic button and suture system offers an alternative method for repairing the distal tibio-fibular joint. Suture-button design has been shown to maintain the reduction, facilitating physiologic stability of the ankle mortise. This may allow early physiological motion, leading to earlier ligament healing and potentially earlier loading, which may produce better clinical results. However, this system is more expensive than the screw method and it may gradually relax under weightbearing conditions. Therefore, whether this device is a suitable alternative, and how many devices are needed for adequate stability are not yet known.

Inclusion criteria

• Unstable unilateral syndesmotic injuries that was considered by the attending staff surgeon to require surgical fixation, including:

• Age : 18 - 60 years old.
• Closed or grade I open fractures are included.
• Isolated syndesmotic injury.
• associated lateral malleolus fracture with talar shift.
• Associated with Bimalleolar fractures.
• Associated with Trimalleolar fractures that did not require posterior fragment fixation (typically <25% of articular surface).

Exclusion criteria

• Exclusion criteria include patient and injury specific factors.

Patient-related exclusion factors included:

• Skeletal immaturity.
• Previous ipsilateral ankle surgery.
• Non-ambulatory status before injury.
• Inability to comply with postoperative protocol (i.e., advanced dementia).
• Medical unfit patients for surgery.
• Uncontrolled diabetes mellitus with charcot joint or peripheral neuropathy.
• Polytrauma patients.

Injury-related exclusion factors included:

• Grade II or III open fractures
• Tibial plafond fractures
• Posterior malleolar fractures requiring fixation (typically >25% articular surface involved).