History
All patients with ankle injury should be evaluated for extensive and serious trauma, depending on the circumstances.
Details of the trauma, such as the direction of torque force applied to the ankle and the position of the foot, help predict the nature and severity of an ankle injury. Although patients tend to recall the event, they often cannot describe the exact manner in which the injury occurred.
History of prior trauma to the affected ankle may cause antecedent laxity, instability, or radiographic abnormalities misinterpreted as an acute event. Chronic medical conditions, such as diabetes, peripheral vascular disease, and metabolic bone disease, may affect examination findings and treatment plans. Long-term medication use is an important part of the history and has implications for management. For example, long-term use of corticosteroids may provoke premature osteoporosis, whereas nonsteroidal anti-inflammatory drugs (NSAIDs) may mitigate the degree of swelling normally expected with fracture.
Physical
Because a patient with ankle fracture often presents with symptoms similar to those of an ankle sprain, a complete and thorough examination of the involved extremity is needed to avoid misdiagnosis and prevent unnecessary radiographs. Indicators suggesting fracture include gross deformity, swelling (especially perimalleolar), bony tenderness, discoloration, and ecchymosis. Inability to bear weight on the injured foot also suggests a fracture. The prognosis for ankle fracture can be improved with prompt, accurate diagnosis and appropriate treatment and referral.
Corroborate any visible deformity by gently manipulating the affected area. Inspect carefully for the presence of open wounds close to the injured ankle.
Assess the neurovascular status of the foot and ankle. Compare these findings with the unaffected extremity. Check for the presence and quality of pulse of the posterior tibial artery. Use a handheld Doppler to document arterial patency. Check for the presence and quality of pulse of the dorsalis pedis artery. Note that the dorsalis pedis is congenitally absent in 10-15% of the population. Document the time needed for capillary refill.
Palpate for focal bony tenderness, especially along the medial and lateral malleoli and the posterior aspect of the joint. If possible, palpate the most tender area last.
Assess passive and active range of motion of the ankle joint, noting limitations. During the immediate acute phase, most patients' ankles are too tender for them to cooperate with stress testing of the joint.
Examine the ipsilateral knee and foot, particularly documenting the condition of the proximal fibula and the proximal fifth metatarsal.
Causes
Multiple classification schemes are used to classify ankle fractures. The Lauge-Hansen system categorizes ankle fractures based on the position of the foot and forces acting on it at the time of injury [8] ; the Danis-Weber system relies on the level of fibular fracture. [9] Neither classification scheme has proved prognostic, so emergency medicine physicians usually label ankle fractures according to the number of fractures in the ankle (unimalleolar, bimalleolar, trimalleolar). [2]
Types of ankle fractures
Pilon fracture
A pilon fracture designates a fracture of the distal tibial metaphysis combined with disruption of the talar dome. An axial loading mechanism drives the talus into the tibial plafond (the distal articular surface of the tibia). A common method of trauma is a foot braced against a floorboard in an auto collision. Skiers coming to an unexpected sudden stop and victims of free fall from heights also may sustain pilon fractures. Pilon fractures account for 1-10% of all tibial fractures.
Establish vascular and integument integrity. Pilon fractures are often open. Skin sloughing is not uncommon. Subsequent edema, fracture blisters, and skin necrosis from the original injury may convert closed fractures to open injuries.
Depending on the trauma, associated injuries include spinal compression fractures (especially of L1) and ipsilateral or contralateral fractures of the os calcis, tibial plateau, pelvis, or acetabulum.
As pilon fractures are often comminuted and open, significant long-term disability often results.
(A pilon fracture is shown in the radiograph below.)
Pilon fracture in a 35-year-old man who fell 20 ft. Anteroposterior radiograph shows at least 2 fracture lines extending to the articular surface (plafond) of the tibia.
Maisonneuve fracture
A Maisonneuve fracture is defined as a proximal fibular fracture coexisting with a medial malleolar fracture or disruption of the deltoid ligament. Maisonneuve fractures are associated with partial or complete disruption of the syndesmosis. Treatment of Maisonneuve fracture depends on the stability of the ankle mortise. This unstable ankle injury requires operative treatment. [2]
(A Maisonneuve fracture is shown in the radiograph below.)
Maisonneuve injury. Mortise view shows transverse fracture of the medial malleolus and widening of the tibiofibular syndesmosis without a fracture of the fibula. This injury is suggestive of a proximal fibula fracture (Maisonneuve fracture).
Tillaux fracture
A Tillaux fracture describes a Salter-Harris (SH) type III injury of the anterolateral tibial epiphysis caused by extreme eversion and lateral rotation of the ankle. Incidence is highest among adolescents, usually those aged 12-14 years, because the fracture occurs after the medial aspect of the epiphyseal plate of the tibia closes but before the lateral aspect arrests.
Distinguish a Tillaux fracture from a triplane fracture. A triplane fracture is a combination of a Salter-Harris type II and type III fracture and is more likely than a Tillaux fracture to require open reduction internal fixation.
(A Tillaux fracture and a triplane fracture are shown in the radiographs below. [10] )
An 11-year-old girl with juvenile Tillaux fracture. Mortise view shows fracture involving the lateral portion of tibial epiphysis.
A 13-year-old girl with triplane fracture. Anteroposterior radiograph shows a sagittal component through the distal tibia epiphysis.
Pott fracture
Bimalleolar fractures, termed Pott fractures, involve at least 2 elements of the ankle ring. These fractures should be considered unstable and require urgent orthopedic attention.
Cotton fracture
A trimalleolar, or Cotton, fracture involves the medial, lateral, and posterior malleoli. These fractures are considered unstable and require urgent orthopedic attention.
Snowboarder's fracture
With the popularity of snowboarding in the late adolescent and young adult population, it is likely the emergency physician will come across a fracture of the lateral process of the talus, the so-called snowboarding ankle fracture. [11, 12]
A combination of dorsiflexion and inversion of the ankle produces the lateral talar fracture.
A high index of suspicion should accompany treatment of snowboarders who report lateral ankle pain with a normal-appearing ankle radiograph. Computed tomography imaging is often required to diagnose a talar fracture.
Hyperplantarflexion variant ankle fracture
The ankle fracture “spur sign” has been found to be highly associated with the hyperplantarflexion variant ankle fracture, as determined by assessment of injury radiographs. This fracture is composed of a posterior tibial tip fracture with posterolateral and posteromedial fracture fragments separated by a vertical fracture line. The spur sign is a double cortical density at the inferomedial tibial metaphysis. [3]
Bosworth fracture-dislocation
In this rare type of ankle fracture-dislocation, the fibula is posteriorly dislocated. The posterior tibial border blocks fibula reduction. Operative treatment is required to reduce and fix the fibula in the incisura fibularis. [2]
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Maisonneuve injury. Mortise view shows transverse fracture of the medial malleolus and widening of the tibiofibular syndesmosis without a fracture of the fibula. This injury is suggestive of a proximal fibula fracture (Maisonneuve fracture).
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Pilon fracture in a 35-year-old man who fell 20 ft. Anteroposterior radiograph shows at least 2 fracture lines extending to the articular surface (plafond) of the tibia.
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A 13-year-old girl with triplane fracture. Anteroposterior radiograph shows a sagittal component through the distal tibia epiphysis.
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An 11-year-old girl with juvenile Tillaux fracture. Mortise view shows fracture involving the lateral portion of tibial epiphysis.
