The foot and the ankle are the most frequently injured parts
of the body. Fractures of the ankle associated with dislocations
of the ankle joint (fracture-dislocations) are serious injuries
that can lead to long-term morbidity. They occur most commonly in
young people who participate in sports, in those suffering from
falls, or in those involved in motor vehicle collisions. The ankle mortise
and surrounding ligaments make the ankle joint strong and stable.
As a result, isolated ankle dislocations are rare. Ankle dislocations
are usually associated with malleolar fractures or a fracture of
the tip of the tibia. They are open 25 percent of the time. While
there are limited data on the mechanism of injury, most ankle dislocations
lead to posterior or posteromedial displacement and occur from a
force against a plantarflexed foot. Fracture-dislocations are often
treated definitively in the Operating Room. Despite this, patients
benefit from early analgesia and prompt reduction.
Ankle dislocations can be successfully reduced in the Emergency
Department with the use of procedural sedation and longitudinal
traction-countertraction.1 Postreduction management invariably
involves leg immobilization and admission to the hospital after
consultation with an Orthopedic Surgeon. Some closed ankle dislocations
may be managed nonoperatively with good long-term results from a
closed reduction and casting for 6 to 9 weeks.2–5
The ankle joint is composed of the talus, tibia, and fibula.
The inferior articular surface of the tibia is concave in both the
coronal and sagittal planes. The articular surface of the talus
is broader anteriorly and longer on its medial and lateral aspects.6 The
ankle mortise limits rotation of the talus, making the ankle joint
There are three groups of ligaments that provide added stability
to the ankle joint. It is stabilized laterally by the anterior talofibular,
the calcaneofibular, and the posterior talofibular ligaments (Figure
74-1). It is stabilized medially by the deltoid ligament, which
comprises a group of four adjoining ligaments: the anterior and
posterior tibiotalar, the tibionavicular, and the tibiocalcaneal ligaments
(Figure 74-2). The third group of ligaments stabilizes the tibia
to the fibula and forms the tibiofibular syndesmosis. This includes
the anterior and posterior tibiofibular ligaments.
The bony and ligamentous structures of the lateral ankle.
The bony and ligamentous structures of the medial ankle.
Almost all ankle dislocations are associated with ligamentous
ruptures, either partial or complete (Figure 74-3). Approximately
25 percent of ankle dislocations are open. Posterior or posteromedial
ankle dislocations are the most common dislocations of the ankle
joint4,7 (Figures 74-3A and
74-4). While this is what is documented in the literature, by far
the most common ankle dislocations seen by the editors are ...