Lateral Talar Process Fracture combined with Calcaneal Sustentaculum Tali Fracture. Case series and proposal of a possible mechanism of injury

Abstract

Background: Lateral Talar Process fracture in association with a Sustentaculum Tali frac-ture is very uncommon and needs a high clinical suspicion, a thorough clinical examination, and a careful radiological evaluation. The mechanism of this combined injury is not clear yet, as only a few references in a small number of case series exist.

Methods: We present a series of four patients sustaining a Lateral Talar Process fracture, with a Sustentaculum Tali fracture in two of them. All patients were treated operatively, either with open reduction and internal fixation or with arthroscopic excision of the frag-ments in one case.

Results: All fractures treated with internal fixation were united, with very good to excellent results. The mean American Orthopaedic Foot and Ankle Society hindfoot score was 93.6 and the mean Foot and Ankle Disability Index score was 89.3. All patients returned to their previous activities with mild, occasional pain in two of them.

Conclusion: An association of a Lateral Talar Process and a Sustentaculum Tali fracture was observed in half of the patients. The mechanism of the combined injury may involve axial loading and subtalar subluxation. Once the articular surfaces commence shifting, if the force responsible for the instability continues to exert, the combined injury may occur. Therefore, if one fracture is encountered, CT scan images should be methodically scrutinised for the presence of the other fracture, especially, in patients with a mechanism of injury involving snowboarding or a fall from a height.

LEVEL OF CLINICAL EVIDENCE: IV