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 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. 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 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 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 89-1). 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 89-2). 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 89-3). They are often associated with malleolar and distal fibula fractures. While posterior or posteromedial ankle dislocations are the most commonly described dislocations of the ankle joint4,7 (Figures 89-3A & 89-4). The most common ankle dislocations seen by the editor are lateral ankle fracture-dislocations (Figure 89-3B). Posterior ankle dislocations are associated with ...