Management of syndesmotic injuries: What is the evidence?

Abstract

Ankle fractures are accompanied by a syndesmotic injury in about 10% of operatively treated ankle fractures. Usually, the total rupture of the syndesmotic ligaments with an external rotation force is associated with a Weber type B or C fracture or a Maisonneuve fracture. The clinical assessment should consist of a comprehensive history including mechanism of injury followed by a specific physical examination. Radiographs, and if in doubt magnetic resonance imaging, are needed to ascertain the syndesmotic injury. In the case of operative treatment the method of fixation, the height and number of screws and the need for hardware removal are still under discussion. Furthermore, intraoperative assessment of the accuracy of reduction of the fibula in the incisura using fluoroscopy is difficult. A possible solution might be the assessment with intraoperative three-dimensional imaging. The aim of this article is to provide a current concepts review of the clinical presentation, diagnosis and treatment of syndesmotic injuries.

Keywords: Ankle; Ankle sprain; Syndesmotic injury; Syndesmotic screw; Three-dimensional; TightRope.

Figure 1

Intra-operative assessment of the syndesmotic integrity in a Weber B fracture with the hook test under fluoroscopy (Mortise view). In this case, the tibiofibular clear space (red arrow) and the medial clear space (yellow arrow) do not open indicating that the syndesmotic ligaments are intact.

Figure 2

Illustration of the plain radiographs of the ankle (Copyright by AO Foundation, Switzerland). AP: Anterior-posterior.

Figure 3

Examples for radiographs of the ankle: Mortise view (A) and lateral view (B).

Figure 4

The increased tibiofibular clear space (red arrow) and medial clear space (yellow arrow) are highly suspicious for a syndesmotic lesion (A) and the radiograph of the proximal part of the lower leg is showing a Maisonneuve injury (blue arrow) (B).

Figure 5

Schematic illustration of the avulsion fractures of the anterior part of the syndesmosis (Tubercule de Chaput, Wagstaffe fragment) and posterior Volkmann fragment (Copyright by AO Foundation, Switzerland).

Figure 6

Axial plane of magnetic resonance imaging showing a full thickness tear of the anterior part of the syndesmosis (red arrow).

Figure 7

Intraoperative visualization of the anterior part of the syndesmosis; in this patient the anterior part of the syndesmosis is completely disrupted (hold with the pincers).

Figure 8

A 25-year-old patient with a Maisonneuve injury. Assessment of reduction with intra-operative three-dimensional scan (A-E): After closed reduction and temporary fixation with a k-wire (A) the three-dimensional scan shows malreduction of the distal fibula in the incisura (B). Immediate intraoperative revision was performed (C) with repeated intraoperative three-dimensional scan showing correct reduction of the distal fibula. With k-wire in place, two syndesmotic screws have been placed to stabilize the ankle diastase (E).