- Discussion:
- pronation of forefoot is combination of external rotation at ankle, abduction of
hindfoot, & eversion of forefoot;
- in pronation, the medial structures tighten and are injured first;
- Sequence of Injury:
-
avulsion frx of medial malleolus or rupture of
Deltoid Ligament;
- malleolus will have a transverse frx;
- abduction force then either
ruptures syndesmotic ligaments
or avulses their bony attachment sites;
- lateral force from talus impacts and
fractures Fibula at or above level of
syndesmosis & ruptures interosseous membrane up to level of this frx;
- fracture is either oblique or partially transverse;
- occassionaly has a butterfly fragment, making it unstable;
- Associated Injuries:
-
dome fractures of the talus are common in this shearing fracture;
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Results of operative treatment of displaced external rotation-abduction
fractures of the ankle.