Evaluation of the syndesmotic-only fixation for Weber-C ankle fractures with syndesmotic injury

Abstract

Background: With the length of the fibula restored and the syndesmosis reduced anatomically, internal fixation using a plating device may not be necessary for supra-syndesmotic fibular fractures combined with diastasis of inferior tibio-fibular joint. A retrospective observational study was performed in patients who had this injury pattern treated with syndesmosis-only fixation.

Materials and methods: 12 patients who had Weber type-C injury pattern were treated with syndesmosis only fixation. The treatment plan was followed only if the fibular length could be restored and if the syndesmosis could be anatomically reduced. Through a percutaneous or mini-open reduction and clamp stabilization of the syndesmosis, all but one patient had a single tricortical screw fixation across the syndesmosis. Patients were kept non-weight-bearing for 6 weeks, followed by screw removal at an average of 8 weeks. Outcomes were assessed using an objective ankle scoring system (Olerud and Molander scale) and by radiographic assessment of the ankle mortise.

Results: At a mean follow-up of 13 months, the functional outcome score was 75. Excellent to good outcomes were noted in 83% of the patients. Ankle mortise was reduced in all cases, and all but one fibular fracture united without loss of fixation. Six patients had more than one malleolar injury, needing either screw or anchor fixations. One patient had late diastasis after removal of the syndesmotic screw and underwent revision surgery with bone grafting of the fibula. This was probably due to early screw removal, before union of the fibular fracture had occurred.

Conclusion: We recommend syndesmosis-only fixation as an effective treatment option for a combination of syndesmosis disruption and Weber type-C lateral malleolar fractures.

Keywords: Weber type-C ankle fractures; functional outcomes; syndesmosis-only fixation; syndesmotic disruption.

Figure 1

X-ray lower third leg bones with ankle joint (anteroposterior and lateral view) showing (a) pre-reduction Weber type-C ankle fracture with syndesmotic disruption (b) post reduction X-ray with syndesmotic screw

Figure 2

(a) Stage 4 PER Maisonneuve fracture with syndesmosis failure: pre- and post-fixation (b) Ankle radiograph of the same patient showing medial malleolar fracture and no inferior tibio-femoral overlap (b,c) Post-operative radiograph with the medial malleolus fixed and syndesmosis stabilised with trans-syndesmotic screw

Figure 3a,b

Bimalleolar ankle fracture treated with syndesmosis-only fixation; the post-fixation X-ray at 7 weeks shows imperfectly reduced syndesmosis and inadequate healing of the fibular fracture. This patient had late diastasis after screw removal