Keywords:
Trauma, Education and training, Perception image, Education, Plain radiographic studies, MR, CT, Musculoskeletal joint
Authors:
T. Grieser; Augsburg/DE
DOI:
10.1594/essr2016/P-0011
Imaging findings OR Procedure Details
In the following,
five types of hindfoot and ankle fracture-dislocations will be discussed:
1) trimalleolar upper ankle fracture-dislocation: plain radiograph (Fig.
1) clearly shows a severe fracture-dislocation of the upper ankle joint in a 20-year-old lady,
came off from horseback.
In this case,
a substantial posterolateral joint-forming fragment was failed to be repositioned because of unawareness (lack of pre-operative computed tomography) (Fig.
2).
Revision operation was therefore required.
2) Talar dislocation,
i.e.
luxatio pedis cum talo: a 68-year-old man fallen from stairs suffered a rare fracture-dislocation of the astragalus.
In this peculiar case,
the subsequent CT scan has been misinterpreted as talar fracture alone (Fig.
4),
whereas initial plain radiography clearly showd additional total talar dislocation (Fig.
3).
Consequently,
there is also a complete disruption of the entire upper-ankle ligamentous apparatus as well as substantial soft-tissue damage (Fig.
5).
3) Subtalar dislocation,
i.e.
luxatio pedis sub talo: a 30-year-old male felt down while skating.
On the AP-view radiograph,
a talo-calcaneal dislocation is obvious,
indicating the complete disruption of the strong subtalar interosseous ligaments (Figs.
6 and 7).
4) Fracture-dislocation of the astragal bone: 66-year-old man after fall from a tree: there is disruption of the talar neck with concomitant complete posterior dislocation of the talar body (Fig.
8).
This type-III-fracture-dislocation acc.
to Hawkins classification system represents an emergency with a high rate of subsequent osteonecrosis (Figs.
9,
10).
5) Chopart´s fracture-dislocation is more frequently encountered than isolated talar dislocations: although there is a dislocation of both the talo-navicular and calcaneo-cuboidal joints,
overt dislocations will often be missed on diagnostic images due to spontaneous repositioning.
Navicular fractures may occur (Fig.
11),
however,
subtle bony avulsions are more often visualized (Fig.
12).