Paediatric triplane fractures and adult trimalleolar ankle fractures both arise from a supination external rotation injury. By relating the experience of adult to paediatric fractures, clarification has been sought on the sequence of injury, ligament involvement, and fracture pattern of triplane fractures. This study explores the similarities between triplane and trimalleolar fractures for each stage of the Lauge-Hansen classification, with the aim of aiding reduction and fixation techniques. Imaging data of 83 paediatric patients with triplane fractures and 100 adult patients with trimalleolar fractures were collected, and their fracture morphology was compared using fracture maps. Visual fracture maps were assessed, classified, and compared with each other, to establish the progression of injury according to the Lauge-Hansen classification.Aims
Methods
Stable fractures of the ankle can be safely treated
non-operatively. It is also gradually being recognised that the integrity
of the ‘medial column’ is essential for the stability of the fracture.
It is generally thought that bi- and tri-malleolar fractures are
unstable, as are pronation external rotation injuries resulting
in an isolated high fibular fracture (Weber type-C), where the deltoid
ligament is damaged or the medial malleolus fractured. However,
how best to identify unstable, isolated, trans-syndesmotic Weber
type-B supination external rotation (SER) fractures of the lateral
malleolus remains controversial. We provide a rationale as to how to classify SER distal fibular
fractures using weight-bearing radiographs, and how this can help
guide the management of these common injuries. Cite this article:
It has previously been suggested that among unstable
ankle fractures, the presence of a malleolar fracture is associated
with a worse outcome than a corresponding ligamentous injury. However,
previous studies have included heterogeneous groups of injury. The
purpose of this study was to determine whether any specific pattern of
bony and/or ligamentous injury among a series of supination-external
rotation type IV (SER IV) ankle fractures treated with anatomical
fixation was associated with a worse outcome. We analysed a prospective cohort of 108 SER IV ankle fractures
with a follow-up of one year. Pre-operative radiographs and MRIs
were undertaken to characterise precisely the pattern of injury.
Operative treatment included fixation of all malleolar fractures.
Post-operative CT was used to assess reduction. The primary and
secondary outcome measures were the Foot and Ankle Outcome Score
(FAOS) and the range of movement of the ankle. There were no clinically relevant differences between the four
possible SER IV fracture pattern groups with regard to the FAOS
or range of movement. In this population of strictly defined SER
IV ankle injuries, the presence of a malleolar fracture was not
associated with a significantly worse clinical outcome than its
ligamentous injury counterpart. Other factors inherent to the injury
and treatment may play a more important role in predicting outcome.
