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INTRODUCTION

The foot and the ankle are commonly injured parts of the body. Fractures of the ankle associated with dislocations of the ankle joint (i.e., fracture-dislocations) or isolated ankle dislocations without fracture are serious injuries that can lead to long-term morbidity. Ankle dislocations are high-energy injuries that occur most commonly in young people from sports, falls, or motor vehicle collisions.1-3 The ankle mortise and surrounding ligaments make the ankle joint strong and stable. This makes isolated ankle dislocations uncommon. Ankle dislocations are usually associated with malleolar fractures or a fracture of the tip of the tibia. They are open 25% of the time. 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. Definitive management of fracture-dislocations is most often surgical. The patient benefits 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. The key to a successful outcome is anatomic restoration and healing of the ankle mortise.1 Postreduction management involves leg immobilization and 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.4-8

ANATOMY AND PATHOPHYSIOLOGY

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.9 The ankle mortise limits rotation of the talus and make the ankle joint inherently stable.

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 111-1). It is stabilized medially by the deltoid ligament. The deltoid ligament comprises a group of four adjoining ligaments: the anterior and posterior tibiotalar, the tibionavicular, and the tibiocalcaneal ligaments (Figure 111-2). The third group of ligaments stabilizes the tibia to the fibula and forms the tibiofibular syndesmosis. This includes the anterior and posterior tibiofibular ligaments.

FIGURE 111-1.

The bony and ligamentous structures of the lateral ankle.

FIGURE 111-2.

The bony and ligamentous structures of the medial ankle.

Almost all ankle dislocations are associated with partial or complete ligamentous ruptures (Figure 111-3).10 They are often associated with malleolar and distal fibula fractures due to the relative strength of the ligaments compared to the malleoli.1,2,11 This results in one or both malleoli fracturing rather than ...

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