Chapter 60: Fractures and Dislocations of the Talus

David W. Sanders

Chapter Outline

Introduction to Fractures and Dislocations of the Talus

Fractures and dislocations of the talus are challenging injuries. The frequent incidence of serious complications, such as osteonecrosis, associated with talus fractures leads to a substantial risk of unsatisfactory results. Since the early descriptions by Anderson4 and others of the “aviator’s astragalus,” fractures of the talus have earned a reputation as a problematic fracture. In Greek mythology, Talos was a giant, grotesque bronze god with a singular large vein coursing through his body. His crucial weakness was related to his vulnerable vascularity, which allowed exsanguination to occur with relative ease. 
Over time, the understanding of talus fractures has evolved such that orthopedic surgeons are well aware of the inherent dangers of this injury. Our understanding of the biology of bone repair and the vascular supply to the talus has grown. Surgical techniques, timing, and instrumentation have changed. The availability of appropriately sized implants and locking plates has improved the surgeon’s ability to reconstruct talar injuries. Nonetheless, talus fractures remain among the most interesting and difficult injuries in orthopedic trauma. 
Fractures of the talus are generally thought to be relatively uncommon. However, the talus is the second most commonly fractured tarsal bone. In recent years, improved recognition has resulted in an increased number of talar process fractures being diagnosed. Coltart30 reviewed 228 talus fractures and noted that chip and avulsion injuries were most common, followed by fractures of the talar neck. Although sports injuries often account for talar process fractures, fractures of the talar neck and body are often secondary to high-energy trauma. 
Fracture of the head of the talus is a very uncommon injury with a lower incidence than talar neck or body fractures. These fractures may be seen in conjunction with talar neck and body fractures, as well as fractures elsewhere in the foot. In most cases, the fracture line involves the articular surface of the talar head such that the talonavicular joint is involved. The injury is often associated with talonavicular subluxation and may be complicated by talonavicular arthritis. 
The literature related to talar process fractures emphasizes two key points: That the injuries are commonly misdiagnosed and that early treatment improves functional results. Fractures of the lateral process of the talus are the most common process fracture. The injury was described by Dimon39 in 1961. Recently, the association between snowboarding and lateral process fractures has been recognized, leading to the term “snowboarder’s fracture.” The anatomy of fractures of the posterior process of the talus is deceptively complex. Together, the medial and lateral tubercles comprise the posterior talar process (Fig. 60-1). Fracture of the lateral tubercle of the posterior process of the talus was described in 1844 by Cloquet. In 1882, Shepherd180 described the fracture in the English literature. The fracture is often referred to as the Shepherd fracture.111 Fracture of the medial tubercle of the posterior process is an uncommon injury. The injury was described in 1974 by Cedell21 and is sometimes referred to as Cedell’s fracture. Fracture of the entire posterior process of the talus is an uncommon injury, but may require surgical intervention to restore congruity of the ankle and subtalar joints or to relieve pressure on the posterior neurovascular bundle (Fig. 60-2).144 Although limited case series exist regarding talar process fractures, complications predominantly relate to delayed diagnosis, nonunion, and the subsequent development of ankle and hindfoot pain. 
Figure 60-1
 
Posterior view of the talus demonstrating that the posterior process has two tubercles, separated by the groove for the flexor hallucis longus tendon. The posterior fibers of the deltoid insert into the medial tubercle, and the posterior talofibular ligament inserts into the lateral tubercle.
Posterior view of the talus demonstrating that the posterior process has two tubercles, separated by the groove for the flexor hallucis longus tendon. The posterior fibers of the deltoid insert into the medial tubercle, and the posterior talofibular ligament inserts into the lateral tubercle.
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Figure 60-1
Posterior view of the talus demonstrating that the posterior process has two tubercles, separated by the groove for the flexor hallucis longus tendon. The posterior fibers of the deltoid insert into the medial tubercle, and the posterior talofibular ligament inserts into the lateral tubercle.
Posterior view of the talus demonstrating that the posterior process has two tubercles, separated by the groove for the flexor hallucis longus tendon. The posterior fibers of the deltoid insert into the medial tubercle, and the posterior talofibular ligament inserts into the lateral tubercle.
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Figure 60-2
Oblique view of the ankle mortise demonstrating fracture of the entire posterior process of the talus.
(Courtesy of Robert R. Foster, MD.)
(Courtesy of Robert R. Foster, MD.)
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Assessment of Fractures and Dislocations of the Talus

Mechanisms of Injury of Fractures and Dislocations of the Talus

Most serious fractures of the talus are high-energy injuries. Fractures of the talar neck are commonly the result of a hyperdorsiflexion-type injury. Following World War I, Anderson,4 the consultant surgeon to the Royal Flying Corps, described the aviator’s astragalus. Pilots resting the sole of the foot on the rudder bar at the time of impact commonly sustained a hyperdorsiflexion force, resulting in a fracture of the neck of the talus. Flying accidents were also common in the description by Coltart.30 Currently, motor vehicle collisions and falls from a height are more common mechanisms of serious talus fractures. 
The mechanism by which progressive hyperdorsiflexion force causes a talus fracture was described in 1980 by Penny and Davis,158 as follows: 
“With dorsiflexion, initially the posterior capsular ligaments of the subtalar joint rupture, the neck of the talus impacts against the leading anterior edge of the distal tibia, and a fracture line develops at this point and enters the nonarticular portion of the subtalar joint between the middle facet and the posterior facet. With a continuation of the dorsiflexion force the calcaneus with the rest of the foot and including the head of the talus subluxes forward. If there is a concomitant inversion component to the force, the foot may sublux or dislocate medially (if there is a concomitant eversion force, the foot dislocates laterally). If the force subsides at this moment, the foot recoils, the body of the talus tips into equinus and the fracture surface of the neck comes to ride on the upper surface of the os calcis. A continuation of the dorsiflexion force, however, produces further rupture of the posterior ankle capsular ligaments, the strong posterior talofibular ligament, and the superficial and posterior aspects of the deltoid ligament. The body of the talus is then wedged posteriorly and medially out of the mortise and rotates around a horizontal and transverse axis so that the fracture surface faces upward and laterally. This is a constant position for the body when there has been dislocation of the body out of the mortise occurring because of the direction of the posterior facet of the subtalar joint, and because the talus pivots around the intact deep fibers of the deltoid ligament and flexor hallucis longus tendon. The body of the talus then comes to lie in the interval between the posterior aspect of the medial malleolus and the anterior aspect of the tendo Achillis. It may be tightly jammed behind the medial malleolus, which is often concomitantly fractured, and the sustentaculum tali. The posterior tibial neurovascular structures almost invariably evade injury by this mechanism, lying anterior to and being protected by the flexor hallucis longus tendon.” 
In a laboratory study, Peterson et al.161 applied a dorsiflexion force to cadaver specimens and were unable to produce a talar neck fracture. In their study, the typical talar neck fracture pattern occurred with the application of an axial load to the plantar surface of the foot when the body of the talus was fixed as a cantilever between the tibia and the calcaneus.161 
Fractures of the talar body result from an axial compression of the talus between the tibial plafond and the calcaneus, and are commonly high-energy injuries. Common mechanisms of injury include motor vehicle collisions and falls from a height. Depending upon whether the force is more posterior or anterior and the relative plantarflexion or dorsiflexion position of the ankle, the force may be directed through the posterior or anterior aspect of the talar body. In many cases, fractures of the talar body are associated with other fractures of the foot and ankle.116 Combined talar neck and talar body fractures were noted in 40% of fractures in a study by Vallier et al.205 These higher-energy fractures are primarily caused by an axial load mechanism. While falls were the most common mechanism of talar body fractures overall, vehicular trauma was more common in combined fractures of the talar neck and body in one series.205 Other associated injuries include fractures of the tibial plafond, medial and lateral malleoli, fractures of the posterior and lateral talar processes, and fractures of the calcaneus, particularly involving the sustentaculum.178 Because of the severe mechanism of injury, other associated injuries to the lower extremities are also commonly noted in conjunction with fractures of the talar body. Open talar body fractures occur in approximately 20% of cases.205 
Talar head fractures result from an axial load applied to the talar head through the navicular bone. The fracture is often described as a compression fracture and may result in significant impaction to the articular surfaces of the navicular and the talar head. Coltart30 described six cases of which four occurred as a result of flying accidents, presumably because of a “rudder bar” injury. He theorized the force of impact was transmitted along the longitudinal axis of the foot through the metatarsals and navicular, with the foot held in extreme plantarflexion, such that a compression force was applied to the talar head.30 The navicular may also fracture as a result of the compressive force.15 In some cases, the fractures are associated with midfoot injuries, particularly divergent tarsometatarsal joint injuries. 
Fractures of the lateral process of the talus have received increasing attention in recent years because of the association between this fracture and snowboarding.147 Kirkpatrick et al.104 reviewed over 3,000 snowboarding injuries from 12 Colorado ski resorts and noted 74 lateral process fractures. It has been suggested that the fracture results from a combination of ankle inversion and dorsiflexion. However, in a cadaver study, Funk et al.56 noted that eversion of a dorsiflexed and axially loaded ankle was more likely to result in a lateral process fracture. Similarly, Boon et al.14 combined external rotation with dorsiflexion, inversion, and axial loading and reproduced lateral process fractures in 75% of the specimens. A patient with bilateral lateral process fractures was described, in whom the mechanism of injury was predominantly axial loading. The fractures occurred when the patient landed a jump on his dirt bike with both feet planted on the foot-pegs.8 Likely, avulsive and axial loading mechanisms can both result in variants of lateral process fracture. Stress fractures of the lateral process may also occur particularly in running athletes.11,140 
Hawkins75 divided fractures of the lateral process into three groups: A nonarticular chip fracture, a single large fragment involving the talofibular and subtalar articulations, and a comminuted fracture involving both articulations. In some cases, the fracture may be associated with subtalar joint incongruity or have marked displacement. 
Fractures of the lateral tubercle of the posterior process may occur as a result of avulsion mechanisms or direct compression. Inversion of the ankle causes avulsion via the posterior talofibular ligament.106 Compression of the lateral tubercle between the calcaneus and the posterior tibia with the ankle in extreme equinus may also cause fracture.72,82,106,123,129,166 Repetitive trauma leads to fracture in kicking athletes related to the forced equinus position of the foot upon impact.123,211 Alternatively, pain may result from a failure of fusion of the secondary ossification center of the posterior process with the talar body, especially in adolescents exposed to repetitive hindfoot stresses.211 
Various mechanisms have been proposed for fractures of the medial tubercle of the posterior process. Most commonly, fracture of the medial tubercle occurs via avulsion. With forceful pronation and dorsiflexion, the posterior deltoid ligament avulses the medial tubercle.21,92,102,103,187 Alternate mechanisms include direct trauma to the posteromedial talar facet,214 impingement of the sustentaculum tali in supination,29 and forced dorsiflexion in high-energy trauma.40 
On occasion, talus fractures can be associated with neuropathic joints.24 Typically, the midfoot progressively dorsiflexes relative to the body of the talus, resulting in significant loss of ankle motion and deformity of the hindfoot. The talar body can eventually become prominent medially and even progress toward dislocation. 

Associated Injuries with Fractures and Dislocations of the Talus

Talus fractures are commonly associated with other musculoskeletal injuries and systemic trauma. Management of the talus fracture in the multiply injured patient can be difficult, as life-saving priorities may necessarily delay access to treatment of extremity injuries. An important principle remains emergent reduction of dislocated joints whenever possible, and early stabilization of fractures and dislocations to facilitate management.23,34,98 
In the multiply injured patient, appropriate initial assessment includes the Advanced Trauma Life Support (ATLS) protocols for management. Where possible, an emergent reduction of dislocated joints can be performed followed by either external95,96 or internal fixation.175 Foot injuries are among the most commonly missed injuries in the multiply injured patient.202 In a series of talar fractures from a Level 1 trauma center, 31 out of 70 talar neck fractures occurred in multiple trauma patients with an injury severity score of greater than 16, and 41 of 70 fractures were associated with other ipsilateral lower extremity injuries.173 
Other high-energy foot injuries may be associated with talus fracture-dislocations, particularly in patients who have fallen from a height or sustained major motor vehicle trauma. High-energy foot injuries should be managed in conjunction with the talus fracture such that early reduction and stabilization of all dislocated joints can be achieved.78,88 In many cases, the management of dislocated joints, as well as management of soft tissue problems, may preclude further definitive fixation or internal fixation of fractures; however, where possible, early stabilization of the joints is preferred.149 High-energy foot injuries seem to be increasing in frequency related in part to the increasing use of air bags in motor vehicles. Patients with serious foot and ankle injuries, who previously may have died from chest, head, and visceral injuries, are now more likely to survive and require treatment. Foot injuries can be disabling in terms of long-term outcome for the patient. 
Associated fractures of the foot and ankle are commonly seen with fractures of the talar neck and body. In a study by Vallier et al.,204 associated foot and ankle fractures occurred in 44 of 100 patients. Talus fractures are frequently associated with tibial plafond and malleolar fractures. The incidence of associated malleolar injury has ranged from 19% to 28% in prior studies.19,118 Fractures of the distal tibia and fibula are addressed in conjunction with the talus fracture and often afford a means of exposure of the talar body, such as through a malleolar fracture site. Tibiofibular diastasis has been found in conjunction with talar neck fractures.66 A 10% incidence of calcaneal fractures has also been reported in conjunction with talar neck fractures.118 

Signs and Symptoms of Fractions and Dislocations of the Talus

Only 2% of all lower extremity injuries and 5% to 7% of foot injuries involve fractures of the talus. Talus fractures frequently occur in a young, active, and mobile population, and can occur from either high- or low-energy trauma. Fractures of the neck and body of the talus are usually higher-energy injuries, often associated with other injuries, and commonly present with foot and ankle swelling and deformity. In contrast, injuries involving the talar processes can be initially very difficult to detect as the physical examination may be almost normal, with the exception of slight tenderness distal to the medial or lateral malleolus. A high index of suspicion is required for the detection of talar process fractures whenever ankle inversion or eversion injuries occur. Specialized radiographic views or cross-sectional imaging may be required. 
Injuries to the soft tissue envelope are seen in conjunction with high-energy talar fractures, such as Hawkins type III injuries, in which the talar body can be extruded posteromedially and rotated on the deltoid ligament.75 Soft tissue compromise is common to talar fracture-dislocations, although the injury does not always penetrate the skin. When the talus fracture is open, the situation can be even more devastating. In some cases, the talar body can be completely extruded as all soft tissues can be detached from the bone.185 The talar body may even be left at the scene of the injury. Management of the extruded or absent talus is especially challenging. 
When the talus is dislocated, an urgent reduction is mandatory to minimize additional soft tissue injury and skin necrosis. Urgent reduction of the dislocated talus is one of the key principles of management. 
Neurovascular injury can be associated with talus fractures. Frequently, however, even when the talus is dislocated posteromedially, relative protection of the neurovascular bundle is afforded by the flexor hallucis longus tendon such that the posterior tibial nerve and vessels are usually intact.23 Vascular injury to the talus itself, however, is frequently noted and is the predisposing factor associated with osteonecrosis of the talus. For example, when the talus is dislocated posteromedially, the arteries of the tarsal sinus and tarsal canal are usually disrupted, as are the dorsal neck branches such that the only remaining vascular supply to the talar body may be through the deltoid ligament. 
Perfusion to the foot is usually intact, even in talar fracture-dislocations. Open fracture-dislocations occurring from an “inside-out” mechanism may cause the talus to extrude posteromedially around the posterior tibial neurovascular bundle. Even so, an intact flexor hallucis longus seems to provide some protection to the neurovascular bundle by preventing excessive tearing or stretching. Vascular compromise may be more common in “outside-in” open fractures such as auger injuries or high-energy crushing or shearing mechanisms. A detailed assessment of the vascular and neurologic status of the foot is required in the initial management of severe talus injuries. 
The clinical presentation of talar head and process fractures ranges from extremely subtle, commonly missed injuries to a markedly swollen ankle, hindfoot, and midfoot. Tenderness to palpation can usually be detected at the site of injury. Careful examination is useful to demonstrate the findings of any associated foot injury, and in particular associated midfoot injuries. Talar head fractures are the most apparent of these injuries; patients are usually in substantial pain and discomfort and foot deformity may be present. In contrast, the mechanism of injury, location of symptoms, and physical findings of a lateral process fracture mimic those of an inversion ankle sprain. Swelling and ecchymosis are commonly localized to the lateral aspect of the ankle. Point tenderness is localized to the lateral process, and most patients retain the ability to bear weight. As a result, lateral process fractures are commonly overlooked.201 Mukherjee et al.141 reviewed 1,500 sprains and fractures of the ankle region and found 13 cases of lateral process fracture. The diagnosis of lateral process fracture should be considered in patients with acute findings similar to an ankle sprain, patients previously diagnosed with an ankle sprain who do not appear to be recovering in the usual time course, and those who present with chronic lateral ankle pain. 
Patients with a posterior process fracture also present with symptoms comparable to an ankle sprain. Tenderness can be elicited more posteriorly compared to a typical sprain, over the posterolateral or posteromedial ankle. Injuries are often missed and patients frequently present weeks or months following the injury, usually with symptoms of posteromedial ankle pain. Motion of the ankle and subtalar joints may be painful. Active flexion of the great toe may produce pain, as the flexor hallucis longus tendon moves over the fracture site. Dougall and Ashcroft40 described a patient with complete entrapment of the flexor hallucis longus tendon in the fracture. In this instance, the patient presented with an inability to extend the great toe as well as posteromedial ankle symptoms.40 

Imaging and Other Diagnostic Studies for Fractures and Dislocations of the Talus

Plain Radiographic Views

Because of its unique shape and associated processes, a variety of plain radiographic views are important to visualize the talus. Standard anteroposterior, lateral, and mortise views of the ankle are a starting point to assess fractures of the talar body, talar neck, and the associated processes. However, in many cases, standard plain radiographic views are inadequate to demonstrate relatively subtle fractures of the talus and to give adequate visualization of comminution and alignment. Canale and Kelly19,20 described a view of the talar neck achieved by internal rotation of the foot by placing the foot plantigrade on an x-ray film and angling the beam at 75 degrees to the perpendicular. Pronation of the foot or internal rotation of the limb will achieve rotation of the talus such that the medial aspect of the talar neck can be well visualized. This view is useful intraoperatively to assess the reconstruction of a talar neck fracture with associated medial comminution and to confirm that varus malalignment has been avoided (Fig. 60-3). 
Figure 60-3
Canale and Kelly view of the foot.
 
The correct position of the foot for x-ray evaluation of the talus is shown.
The correct position of the foot for x-ray evaluation of the talus is shown.
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Figure 60-3
Canale and Kelly view of the foot.
The correct position of the foot for x-ray evaluation of the talus is shown.
The correct position of the foot for x-ray evaluation of the talus is shown.
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Additional useful views include a lateral view of the calcaneus, as associated fractures of the posterior facet can often be seen. A true lateral view of the subtalar joint can be beneficial to assess for comminution and subluxation (Fig. 60-4). Oblique views of the talus are helpful in diagnosing posterior process fractures.46 An anteroposterior view obtained with the ankle externally rotated 30 degrees brings the posteromedial process into profile.44 
Figure 60-4
Intraoperative fluoroscopic evaluation of the talus.
 
A: Canale and Kelly view and lateral image of the subtalar joint. B: Lateral and anteroposterior views of the ankle in a talar neck fracture with an associated lateral process fracture.
A: Canale and Kelly view and lateral image of the subtalar joint. B: Lateral and anteroposterior views of the ankle in a talar neck fracture with an associated lateral process fracture.
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Figure 60-4
Intraoperative fluoroscopic evaluation of the talus.
A: Canale and Kelly view and lateral image of the subtalar joint. B: Lateral and anteroposterior views of the ankle in a talar neck fracture with an associated lateral process fracture.
A: Canale and Kelly view and lateral image of the subtalar joint. B: Lateral and anteroposterior views of the ankle in a talar neck fracture with an associated lateral process fracture.
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Anteroposterior, lateral, and oblique radiographs of the foot demonstrate talar head fracture, often associated with talar neck and body fractures and varying degrees of talonavicular joint subluxation.156 The radiographs may demonstrate shortening of the medial column of the foot with overlap between the talar head and navicular because of the displaced fracture. The displaced fracture fragment commonly involves the dorsomedial or dorsolateral aspect of the talar head, with subluxation of the talonavicular joint occurring toward the displaced fragment. 
Standard ankle radiographs are often insufficient to detect and fully diagnose talar process fractures. Lateral process fractures can best be seen on careful inspection of the mortise view because the fracture line is most commonly in the sagittal plane. Posterior process fracture can be similarly difficult to see on plain radiographs but is usually best demonstrated on the lateral radiograph (Fig. 60-5). Alternatively, medial tubercle posterior process fracture may be visualized as a small flake fragment off the medial wall of the talus in the anteroposterior projection (Fig. 60-6). Comparison views of the contralateral foot are useful to identify and contrast the appearance of an os trigonum. Any rough or irregular surfaces visible should be interpreted as potentially indicative of a fracture of the posterior process, in contrast to the smooth and well-corticated surfaces of the os trigonum. However, plain radiographs often do not demonstrate a talar process fracture well. Computed Tomography (CT) is most helpful at documenting the extent and severity of these fractures (Fig. 60-7). 
Figure 60-5
Lateral radiograph of the ankle showing a fresh fracture of the lateral tubercle of the posterior process of the talus.
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Figure 60-6
Anteroposterior (A) and lateral (B) radiographs of an acute fracture of the medial tubercle of the posterior process of the talus.
The arrows identify the fracture line.
The arrows identify the fracture line.
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Figure 60-7
Coronal CT scan (A) and CT reconstruction (B) demonstrating the medial process fracture depicted in radiographs in Figure 6.
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Because of the difficulty in detecting and defining the extent of a lateral or posterior process fracture, a CT scan is frequently necessary to fully understand the injury. CT will allow an accurate assessment of the size, degree of displacement, and comminution of the fractured process as well as joint involvement, tendon pathology, and any associated injuries.46,48,85,148 Magnetic Resonance Imaging will similarly detect and define talar process fractures and associated injuries.174 

Computed Tomography and Magnetic Resonance Imaging

CT scans are very useful in the assessment of talar fractures and dislocations. CT scans give improved visualization of the congruity of the subtalar joint reduction and provide superior detail compared with plain films. Comminuted fractures of the talus, process fractures, and fractures involving the subtalar joint benefit from the improved detail noted with CT scans as these regions are difficult to visualize on plain films. Compared to plain radiographs, CT imaging has greater accuracy in the detection and characterization of displacement following fixation or displacement associated with malunion.22 
CT scans can be similarly useful to assess subtalar dislocations. Subtalar dislocations are often associated with small but significant fractures of the inferior aspect of the talus, which are better appreciated on CT scans compared to plain films alone. 
New technology includes C-arm–based mobile CT. Although the image quality of this method is still improving, mobile CT may prove to be a significant advantage for intraoperative imaging.213 
MRI has an important role in the assessment of talar fractures, although it is not typically required for diagnosis or initial assessment.97,143 MRI is the most sensitive and specific imaging modality to demonstrate osteonecrosis. MRI has been subject to artifact from the placement of a large volume of stainless steel screws. This problem is lessened when titanium implants are used for fracture fixation. Recently, improved MRI technology has lessened the effect of metallic artifact, such that MRI may provide useful information even in the presence of hardware. 

Classification of Fractures and Dislocations of the Talus

Fractures of the talus are a heterogeneous group of injuries. Varying in severity from devastating to trivial, these injuries necessarily are grouped in several distinct classifications. The most clinically useful general classification separates talus injuries on the basis of their location, into fractures of the talar neck, the talar body, and the talar head and processes. Subtalar dislocations are usually considered separately. 
The most comprehensive classification of talus fractures is described in the Orthopedic Trauma Association’s Fracture and Dislocation compendium.150 Talus fractures are divided into avulsion, process, or head fractures (81-A), neck fractures (81-B), and body fractures (81-C) (Fig. 60-8). Similar to Hawkins’ classification, neck fractures are subdivided into nondisplaced fractures (81-B1), displaced fractures associated with subluxation of the subtalar joint (81-B2), and displaced fractures associated with subluxation of the subtalar and tibiotalar joints (81-B3). Talar body fractures are divided into talar dome fractures (81-C1), talar body fractures with subtalar joint involvement (81-C2), and talar body fractures with subtalar and ankle joint involvement (81-C3). For fractures of the talar head (81-A3), neck (81-B2 and B3), and body (81-C1, C2, and C3) fractures are further classified according to comminution.150 In two large series of talar neck fractures, comminution was independently predictive of outcome.173,204 The presence of severe comminution implies more energy imparted to the fracture resulting in a worse prognosis and outcome. 
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Figure 60-8
The AO/OTA classification of talus fractures.150
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The most commonly used classification for talar neck fractures is that described by Hawkins76 with the modifications suggested by Canale and Kelly.20 In the Hawkins76 classification, type I refers to a fracture without associated joint dislocation, that is, an undisplaced fracture of the talar neck (Fig. 60-9). As noted by Daniels, “There is no room for the term ’a minimally displaced type I talar neck fracture.’”32 In equivocal cases, careful attention should be directed to the subtalar joint alignment to confirm that there is in fact no degree of subtle incongruity and to the clinical examination, as most slightly displaced talar neck fractures are associated with deformity. Often the talar head is rotated relative to the talar body, such that supination of the midfoot and forefoot relative to the hindfoot can be noted. 
Figure 60-9
Nondisplaced vertical fracture of the talar neck, Hawkins type I.
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The Hawkins type II fracture refers to a talar neck fracture with associated subluxation or dislocation of the subtalar joint (Fig. 60-10). This is the most common type of talar neck fracture-dislocation and in some cases is amenable to closed reduction. While osteonecrosis of the body of the talus in Hawkins type I fractures is relatively rare, the incidence of osteonecrosis in type II fractures ranges as high as 40% to 50%.20 
Figure 60-10
Hawkins type II fractures of the talar neck with subluxation (A) and dislocation (B) of the subtalar joint.
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A Hawkins type III fracture involves a dislocation of the ankle as well as of the subtalar joint (Fig. 60-11). In this case, osteonecrosis is the rule rather than the exception with rates of osteonecrosis of nearly 100% in both the Hawkins76 and the Canale and Kelly20 series. With Hawkins type III fractures, the body is most commonly dislocated posteromedially. The talar body fragment can be rotated around the deep fibers of the deltoid ligament and may lie posterior to the long flexor tendons of the foot. These injuries are most commonly irreducible by closed means. 
Figure 60-11
Displaced fracture of the talar neck with dislocation of both the subtalar and tibiotalar joints (Hawkins type III).
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The Hawkins type IV fracture was described by Canale and Kelly20 and implies associated subluxation or dislocation of the talonavicular joint (Fig. 60-12). These injuries are relatively uncommon compared to the Hawkins type II and III fracture-dislocations. The quoted rate of osteonecrosis remains close to 100%. Some authors have grouped comminuted fractures of the talus associated with high-energy foot injuries into the Hawkins IV classification to imply a worse prognosis and because these injuries are difficult to fit into the classification elsewhere. Pantazopoulos et al.152 described a case in which the talar neck fracture was associated with a dislocation of the talar head, but the body remained reduced. This injury was also classified as a Hawkins type IV talar neck fracture.152 
Figure 60-12
Hawkins type IV fracture of the talar neck with subluxation of the subtalar joint and dislocation of the talonavicular joint.
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By definition, fractures of the talar body are intra-articular injuries in which the articular surfaces of the tibiotalar and/or the subtalar joints are involved. Inokuchi et al.86 distinguished talar neck fractures from talar body fractures based upon the location of the inferior fracture line relative to the lateral process of the talus. Based upon the lateral radiograph, fractures extending into or posterior to the lateral process of the talus are defined as talar body fractures, whereas fractures anterior to the lateral process are defined as talar neck fractures. 
Talar body fractures present in a variety of patterns and configurations such that classification can be difficult (Fig. 60-13). Fractures of the talar processes are considered separately from talar body fractures. In general, talar body fractures can be defined as shearing-type fractures or compression-type fractures. The shearing-type fractures may occur either in the sagittal or the coronal plane. The Orthopedic Trauma Association classification considers talar body fractures according to the location of the fracture and the joints involved (Fig. 60-8). Talar body fractures are divided into talar dome fractures (81-C1), talar body fractures with subtalar joint involvement (81-C2), and talar body fractures with subtalar and ankle joint involvement (81-C3). Subclassification is made depending upon whether the fracture is comminuted.150 The location of the primary fracture line is important, particularly when considering the surgical approach or the need for a malleolar osteotomy for exposure of the talar body. 
Figure 60-13
Talar body fracture with associated subtalar dislocation and comminution.
 
A: Preoperative anteroposterior radiograph demonstrates dislocation and fracture comminution. B: Combined lateral and anteromedial surgical approaches were used. Intraoperatively, Kirschner wires achieved provisional fixation (C) followed by definitive screw fixation (D, E).
A: Preoperative anteroposterior radiograph demonstrates dislocation and fracture comminution. B: Combined lateral and anteromedial surgical approaches were used. Intraoperatively, Kirschner wires achieved provisional fixation (C) followed by definitive screw fixation (D, E).
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A: Preoperative anteroposterior radiograph demonstrates dislocation and fracture comminution. B: Combined lateral and anteromedial surgical approaches were used. Intraoperatively, Kirschner wires achieved provisional fixation (C) followed by definitive screw fixation (D, E).
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Figure 60-13
Talar body fracture with associated subtalar dislocation and comminution.
A: Preoperative anteroposterior radiograph demonstrates dislocation and fracture comminution. B: Combined lateral and anteromedial surgical approaches were used. Intraoperatively, Kirschner wires achieved provisional fixation (C) followed by definitive screw fixation (D, E).
A: Preoperative anteroposterior radiograph demonstrates dislocation and fracture comminution. B: Combined lateral and anteromedial surgical approaches were used. Intraoperatively, Kirschner wires achieved provisional fixation (C) followed by definitive screw fixation (D, E).
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A: Preoperative anteroposterior radiograph demonstrates dislocation and fracture comminution. B: Combined lateral and anteromedial surgical approaches were used. Intraoperatively, Kirschner wires achieved provisional fixation (C) followed by definitive screw fixation (D, E).
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Surgical and Applied Anatomy of Fractures and Dislocations of the Talus

The talus is unique in that the majority of its surface is covered by articular cartilage.93 Although there are multiple capsular and ligamentous attachments, no muscles attach directly to the talus.64 The trochlea of the talus, or superior surface, supports the body weight and transmits loads to the inferior aspect of the tibial plafond (Fig. 60-14). The trochlea is wider anteriorly compared to posteriorly such that the medial and lateral sides of the trochlea converge in a posterior direction. On the medial and lateral sides of the talar body, the articular cartilage also extends plantarward to articulate with the medial and lateral malleoli. Much of the inferior side of the talus is also covered by cartilage to form the articulation with the posterior facet of the calcaneus. 
Figure 60-14
Superior and inferior views of the talus (stippling indicates the posterior and lateral processes).
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The osseous architecture of the talus reflects its function in force transmission across the ankle. The cortex of the talus is thicker around the posterior calcaneal facet, the malleolar facets, the talar neck, and at the attachments of major ligaments.5 Swanson and Bray189 described an increase in bone density in the lateral aspect of the talar head and in the inferolateral aspect of the talar body compared with the medial bone (Fig. 60-15). The cancellous bone is organized into two sets of stacked vertical lamellae or plates which are organized primarily from the anteromedial trochlea toward the talar head, and from the posterolateral trochlea inferiorly toward the posterior calcaneal facet.5,47 This arrangement of lamellae facilitates force transmission. During heel strike, weight is transmitted inferiorly toward the calcaneus, and as the gait cycle progresses, an increasing amount of weight is transmitted anteriorly toward the talar head. 
Figure 60-15
 
Left talus horizontal section demonstrating internal lamellar architecture including sagittal plates in the medial body (i) curving toward the talar head (ii) and plates from the lateral process curving anterior (iii) and posterior (iv). (Reproduced from Athavale S, Joshi S, Joshi S. Internal architecture of the talus. Foot Ankle Int. 2008;29:82–86, with permission.)
Left talus horizontal section demonstrating internal lamellar architecture including sagittal plates in the medial body (i) curving toward the talar head (ii) and plates from the lateral process curving anterior (iii) and posterior (iv). (Reproduced from Athavale S, Joshi S, Joshi S. Internal architecture of the talus. Foot Ankle Int. 2008;29:82–86, with permission.)
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Figure 60-15
Left talus horizontal section demonstrating internal lamellar architecture including sagittal plates in the medial body (i) curving toward the talar head (ii) and plates from the lateral process curving anterior (iii) and posterior (iv). (Reproduced from Athavale S, Joshi S, Joshi S. Internal architecture of the talus. Foot Ankle Int. 2008;29:82–86, with permission.)
Left talus horizontal section demonstrating internal lamellar architecture including sagittal plates in the medial body (i) curving toward the talar head (ii) and plates from the lateral process curving anterior (iii) and posterior (iv). (Reproduced from Athavale S, Joshi S, Joshi S. Internal architecture of the talus. Foot Ankle Int. 2008;29:82–86, with permission.)
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The neck of the talus has multiple vascular foramina, particularly on the dorsal neck where capsular and ligamentous attachments originate (Fig. 60-16). The neck of the talus deviates medially by about 15 to 20 degrees. The head of the talus has rounded cartilaginous facets to articulate with the navicular anteriorly. The spring ligament wraps around the inferior aspect of the talar head and the deltoid ligament attaches to the medial aspect of the talar body. There is a wide area of attachment for the deltoid ligament extending from the talar body onto the medial aspect of the neck. 
Figure 60-16
 
Superior view of the right talus demonstrating the convergence of the sides of the trochlear surface and the vascular foramina on the neck. (From Giannestras NJ. Foot Disorders: Medical and Surgical Management. 2nd ed. Philadelphia, PA: Lea & Febiger; 1973.)
Superior view of the right talus demonstrating the convergence of the sides of the trochlear surface and the vascular foramina on the neck. (From Giannestras NJ. Foot Disorders: Medical and Surgical Management. 2nd ed. Philadelphia, PA: Lea & Febiger; 1973.)
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Figure 60-16
Superior view of the right talus demonstrating the convergence of the sides of the trochlear surface and the vascular foramina on the neck. (From Giannestras NJ. Foot Disorders: Medical and Surgical Management. 2nd ed. Philadelphia, PA: Lea & Febiger; 1973.)
Superior view of the right talus demonstrating the convergence of the sides of the trochlear surface and the vascular foramina on the neck. (From Giannestras NJ. Foot Disorders: Medical and Surgical Management. 2nd ed. Philadelphia, PA: Lea & Febiger; 1973.)
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The lateral process of the talus is a large, broad-based, wedge-shaped prominence of the talar body. It is vulnerable to fracture as an isolated injury or associated with fractures of the talar body. The lateral process includes two articular surfaces. Dorsolaterally, it articulates with the fibula; inferomedially, the lateral process articulates with the anterior portion of the posterior facet of the calcaneus. The lateral talocalcaneal ligament originates from the tip of the lateral process (Fig. 60-14).131 
The posterior process of the talus is derived from two tubercles. The inferior aspect of the posterior process is covered by articular cartilage, and the posterior 25% of the posterior articular facet of the subtalar joint is formed by the posterior process. McDougall123 described that the posterior process of the talus arises from a secondary ossification center that fuses with the body of the talus around age 12.123 Together, the medial and lateral tubercles comprise the posterior talar process (Fig. 60-2). The lateral tubercle is larger, projects more posteriorly, and is the tubercle usually seen on a lateral radiograph of the ankle. The posterior talofibular ligament is attached to the lateral tubercle. Between the lateral and medial tubercles is a groove for the flexor hallucis longus tendon. The medial tubercle projects medially and inferiorly from the groove for the flexor hallucis longus. The posterior third of the deltoid ligament is attached to the medial tubercle. 
The os trigonum is an accessory bone of the foot located just posterior to the lateral tubercle of the posterior process. The os trigonum may exist as a separate ossicle or be fused with the lateral tubercle of the posterior process. An os trigonum is present in 50% of normal feet111 and is thought to arise from a separate ossification center just posterior to the lateral tubercle. Burman and Lapidus18 found a separate os trigonum in 64 of 1,000 feet examined by radiograph, and noted a fused os trigonum (defined as an elongated lateral tubercle) in 429 of 1,000 feet. While there is a significant degree of symmetry in the anatomy of the posterior talus between the two feet of any person, the os trigonum may occur as a unilateral structure.18,123 The os trigonum is usually distinguished from a fracture of the lateral tubercle based upon its radiographic appearance. The shape of the os trigonum varies, including round, oval, and triangular shapes, but the edges are well corticated and smooth, unlike an acute fracture. In one series, four of six patients with posteromedial talar fractures were misdiagnosed as having an os trigonum,61 compared with three of five patients in another series.102 In both series, patients with delayed diagnoses presented with chronic posteromedial ankle pain. 

Blood Supply of the Talus

The perfusion of the talus has been extensively investigated.58,64,71,93,113,124,142,162,163,185,212 The talus is largely covered by articular cartilage, leaving limited space for blood vessels to enter via capsular and ligamentous attachments.93 The blood vessels that enter the talus traverse regions of articular capsule and synovial membrane in which they are vulnerable to trauma. Because of the lack of muscular soft tissue attachments and the limited space available for vascular foramina, the talus is predisposed to difficulties with blood supply, and osteonecrosis is a well-recognized complication of trauma to the talus. 
Our understanding of the talar circulation is ascribed to Wildenauer,212 who described the critical anastomotic sling of vessels in the tarsal sinus and tarsal canal, lying inferior to the neck of the talus. Within the tarsal canal and the tarsal sinus, anastomotic vessels perforate the inferior neck to form the primary source of blood supply to the body of the talus. The tarsal sinus is bounded by the calcaneus inferiorly, the body of the talus posteriorly, and the talar head and neck anteriorly. The tarsal canal lies between the talus and calcaneus just behind and below the tip of the medial malleolus. The tarsal sinus and tarsal canal can be likened to a funnel. Kelly and Sullivan93 compare the tarsal sinus to the cone of the funnel and the tarsal canal to the tube of the funnel (Fig. 60-17). The artery to the sinus tarsi and the artery of the tarsal canal form the anastomotic sling inferior to the talus from which branches arise to enter the talar neck area. 
Figure 60-17
The anastomotic sling of vessels that provides the blood supply to the body of the talus.
 
Laterally, the artery of the tarsal sinus (a); medially, the artery of the tarsal canal (b). Additional arteries enter dorsally through the neck and on the medial surface of the body (c).
 
(Kelly PJ, Sullivan CR. Blood supply of the talus. Clin Orthop. 1963;30:38.)
Laterally, the artery of the tarsal sinus (a); medially, the artery of the tarsal canal (b). Additional arteries enter dorsally through the neck and on the medial surface of the body (c).
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Figure 60-17
The anastomotic sling of vessels that provides the blood supply to the body of the talus.
Laterally, the artery of the tarsal sinus (a); medially, the artery of the tarsal canal (b). Additional arteries enter dorsally through the neck and on the medial surface of the body (c).
(Kelly PJ, Sullivan CR. Blood supply of the talus. Clin Orthop. 1963;30:38.)
Laterally, the artery of the tarsal sinus (a); medially, the artery of the tarsal canal (b). Additional arteries enter dorsally through the neck and on the medial surface of the body (c).
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The artery of the tarsal canal arises from the posterior tibial artery just proximal to the origin of the medial and lateral plantar arteries.142 The deltoid branches arise from the artery of the tarsal canal and supply the medial third of the talar body.58 From the anterior tibial, or dorsalis pedis artery, come multiple branches to the dorsal aspect of the talar neck. An additional branch may provide a contribution to the artery of the sinus tarsi. From the peroneal artery come branches to the posterior process and a branch to form the artery of the sinus tarsi. Peterson et al.162 emphasized the important contribution of additional capsular and ligamentous vessels adjoining the talus with the navicular, the calcaneus, and even the tibia through capsular and ligamentous attachments. Intraosseous communications between the major arterial supplies to the talus have also been demonstrated.58 
The talar body receives most of its blood supply from the anastomotic sling in the tarsal canal and tarsal sinus. Many branches of the sling enter the inferior aspect of the neck and course posterolaterally. Additional blood supply originates from the deltoid branches of the posterior tibial artery, contributing significantly to the medial third of the talus. Branches of the peroneal artery may make a minor contribution posteriorly, around the posterior process. The talar head is supplied by branches of the dorsalis pedis arising from the dorsal neck vessels and also from the artery of the tarsal sinus. 
Peterson et al.162 demonstrated that undisplaced fractures of the talar neck can be associated with intraosseous disruption of the branches of the arteries of the tarsal sinus and tarsal canal. However, the major vascular sling should remain intact. With increasing displacement, branches of the dorsalis pedis artery as well as the artery of the tarsal canal and artery of the tarsal sinus can be disrupted. These findings confirm the clinical observation that the rate of osteonecrosis depends upon the degree of fracture displacement.20,76 

Talus Fracture Treatment Options

Outcome following talar neck and body fractures is most dependent upon the development of complications. These include, in particular, osteonecrosis of the talar body, osteoarthritis of the subtalar joint and the ankle joint, delayed union, nonunion, malunion, and infection. Treatment should be directed to an early anatomic reduction of the talar neck fracture and, where possible, avoidance of complications. Anatomic union, in the absence of complications, frequently results in an excellent outcome for the patient.173 

Nonoperative Treatment of Fractures and Dislocations of the Talus

Indications/Contraindications

Nonoperative management has a limited role in fractures of the talar neck. Nonoperative treatment should only be considered for fractures in which there is no displacement of the fracture line and no incongruity of the subtalar joint. According to the Hawkins’ classification system, only type I fractures can be treated nonoperatively. When nonoperative treatment is considered, an anatomic reduction should be confirmed with a CT scan.22 Fractures that are displaced, even slightly, are commonly associated with incongruity of the subtalar joint on careful observation. If subtalar incongruity is present, the injury should be reclassified as a type II fracture and treated with anatomic reduction. 
Historically, closed treatment with cast immobilization was preferred for talar body fractures. Sneppen et al.186 reported on a series of 31 patients with fractures of the talar body. Most patients were treated with closed reduction and casting, and complications were common with high rates of malunion, osteonecrosis, and arthritis. Ninety-five percent of their patients had moderate or severe complaints. They concluded that more aggressive treatment is indicated for displaced fractures and recommended “exact reduction and stable fixation whenever possible.”186 
On the other hand, fractures of the talar head and processes can frequently be treated without surgical intervention. In the case of talar head fractures, principles of treatment include maintenance of the alignment of the dorsomedial arch of the foot, prevention of talonavicular joint incongruity and instability, and maintenance of reduction of the talar head fragment. When a talar head fracture is undisplaced, nonoperative care is indicated as long as the principles of treatment are assured. 
Factors that determine appropriate treatment for lateral process fractures include the size and displacement of the fracture fragment, the degree of comminution, associated injuries, and joint congruity. In general, small fracture fragments and undisplaced fractures are appropriately treated without surgery, with a period of immobilization followed by progressive weight-bearing and motion exercises. In contrast, large fractures associated with significant displacement and involving substantial portions of the subtalar joint are treated with open reduction and internal fixation.79,131 
Treatment of fractures of the lateral and medial tubercles of the posterior process of the talus should be directed toward achieving union. Multiple reports in the literature describe ununited and symptomatic fractures requiring surgical intervention. Patients should be prevented from inversion and plantarflexion of the ankle to avoid displacement (Table 60-1). 
 
Table 60-1
Talus Fractures: Nonoperative Treatment
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Table 60-1
Talus Fractures: Nonoperative Treatment
Indications Relative Contraindications
Undisplaced talar neck fractures
  •  
    Any fracture displacement
  •  
    Any joint incongruity
Undisplaced talar body fractures
  •  
    Any fracture displacement
  •  
    Any joint incongruity
Talar head fractures
  •  
    Incongruity or instability of the talonavicular joint
Lateral process fractures
  •  
    Very large fracture fragments (>1–2 cm)
  •  
    Significantly displaced fractures
  •  
    Subtalar joint incongruity
Posterior process fractures
  •  
    Tendon or nerve impingement
  •  
    Joint incongruity
  •  
    Persistent pain after nonoperative treatment
X

Techniques of Nonoperative Treatment

Nonoperative management of undisplaced talar neck and body fractures includes immobilization and nonweight bearing until clinical and x-ray signs of fracture healing are present, which can require up to 12 weeks.1,2,15,19,20,30,42,76,94,158,164 
For fractures of the talar head and processes in which nonoperative care is indicated, a well-molded short leg cast or cast brace may be used for initial treatment. Although some authors have successfully treated process fractures with simple orthotic insoles, large fragments with risk of displacement likely benefit from some period of immobilization and protected weight bearing.207 In most cases, protection from full weight bearing is maintained until some clinical or radiographic signs of union are present, as nonunion can develop with premature mobilization and weight bearing. At approximately the 6-week mark, full weight bearing can usually be achieved provided a well-fitting shoe with appropriate arch support is used.75 Following mobilization, physical therapy is often required to assist with rehabilitation of both the ankle and subtalar joints. 

Operative Treatment of Talar Neck and Body Fractures

Indications/Contraindications

The vast majority of displaced fractures of the talar neck and body are treated operatively. Operative treatment is indicated to achieve an anatomic reduction of the talar neck fracture. Displacement of the talar neck is associated with subluxation or dislocation of the posterior facet of the subtalar joint. As noted by Adelaar,1 subluxation of the posterior facet of the subtalar joint results from disruption of the interosseous talocalcaneal ligament. The talar body assumes a plantarflexed, malaligned position usually associated with varus deformity. Sangeorzan et al.176 demonstrated the importance of even slight deformity of the talar neck. In their biomechanic study, residual displacements of as little as 2 mm altered the contact characteristics of the subtalar joint. Daniels et al.33 performed a biomechanic study using cadaver specimens and demonstrated that varus malalignment of the talar neck is associated with forefoot adduction, calcaneal internal rotation, and loss of subtalar motion. Severe displacement of the fracture fragments can cause skin tenting and necrosis. When the skin is at risk, prompt reduction of severe malalignment is critical to lessen skin complications and infection. 
An anatomically congruent ankle and subtalar joint complex is important for normal function, as well as to prevent posttraumatic arthritis. Furthermore, anatomic realignment of the displaced fracture reduces soft tissue tension, which may facilitate reperfusion of talar fractures with a partially disrupted blood supply. Operative reduction and fixation, therefore, is the cornerstone of treatment for displaced talar neck and body fractures. 

Closed Reduction

Closed reduction can be performed for fractures of the talar neck, with the unfortunate caveat that achieving a closed reduction can be very difficult. In ideal circumstances, proceeding directly to open reduction and internal fixation may be more effective, and avoids repeated failed attempts at closed reduction. However, when operative intervention will be delayed, when soft tissues are at risk, and for fractures with subluxation but without frank dislocation, closed reduction can be successful and valuable (Fig. 60-18). 
Figure 60-18
Closed reduction of a talar neck fracture.
 
Lateral radiograph demonstrating alignment prereduction (A) and postreduction (B) of a Hawkins type II fracture. Note some displacement persists.
Lateral radiograph demonstrating alignment prereduction (A) and postreduction (B) of a Hawkins type II fracture. Note some displacement persists.
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Figure 60-18
Closed reduction of a talar neck fracture.
Lateral radiograph demonstrating alignment prereduction (A) and postreduction (B) of a Hawkins type II fracture. Note some displacement persists.
Lateral radiograph demonstrating alignment prereduction (A) and postreduction (B) of a Hawkins type II fracture. Note some displacement persists.
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Obtaining a successful closed reduction requires, firstly, adequate analgesia and sedation. The essential technique involves bringing the foot, including the talar head, to the residual talar body fragment. This requires the talar body to be reduced within the ankle mortise. In a type II fracture with subluxation or dislocation of the subtalar joint, a reduction is most likely to be successful with the knee flexed and the foot flexed plantarward. This relaxes the gastrocsoleus complex and brings the talar head fragment into proper relation to the body. At that point, any varus or valgus malalignment can be corrected as well. Once the reduction is achieved, excessive dorsiflexion will cause a redisplacement of the head fragment, and therefore radiographs to confirm reduction should be performed with the foot in a comfortable position of slight equinus. 
In type III fractures, it may occasionally be possible to replace the talar body fragment back into the ankle mortise. This requires plantarflexion and varus positioning of the foot. Closed reduction is aided by the use of a transverse pin placed through the calcaneus to apply traction and control hindfoot varus and valgus. However, direct traction also increases the soft tissue tension around the ankle including the flexor tendons, the posterior tibial tendon, and even the deltoid ligament, and a closed reduction may be more difficult if the tissues are overly tensioned. Direct pressure on the talar body fragment is often required to reduce it relative to the medial malleolus. Excessive or prolonged direct pressure can increase the risk of skin necrosis, such that repeated attempts are not likely to be helpful. 
If a closed reduction is successful and an anatomic reduction is achieved, one can consider open reduction and internal fixation, or percutaneous screw fixation to stabilize the talar neck fracture. Cast treatment can also be considered, but often requires prolonged positioning of the foot in equinus to maintain the reduction, followed by gradual repositioning of the foot into a plantigrade position. Non–weight-bearing immobilization is usually required until union is achieved. If an anatomic reduction is not achieved, it is necessary to proceed to open reduction and internal fixation. 

Open Reduction and Internal Fixation

Operative reduction and internal fixation is the standard treatment for all displaced talar neck and body fractures. There are a number of surgical options available, especially related to surgical approaches and choice of fixation. The critical elements of care are similar to other periarticular fractures—obtaining an anatomic reduction and providing stable internal fixation. In addition, the surgeon should take great care to protect and preserve the viability of the blood supply to the talar body, understanding the high risk of osteonecrosis in this particular fracture. 
Preoperative Planning.
Preparing for surgical reduction and fixation of talar neck and body fractures requires a thoughtful consideration of the specific surgical plan. Not all fractures are identical, and therefore a variety of surgical plans may be required depending upon the fracture “personality.” Critical elements include planning the reduction techniques for fracture/dislocations, and planning the fixation prior to the surgery to ensure the proper equipment is available. Supine positioning on a radiolucent table is standard. The entire limb should be free draped to facilitate internal and external rotation when combined approaches are used, to provide a visual guide to anatomic axial alignment, and to facilitate intraoperative fluoroscopy by allowing the knee and hip to flex fully and place the foot flat on the operating table. An appropriate range of bumps to elevate the affected ankle and gently flex the knee facilitates fluoroscopic visualization and relaxes the gastrocnemius. A thigh tourniquet aids visualization intraoperatively. Specific equipment to aid with reduction includes joint distractors, traction pins, Schanz screws, and malleolar osteotomy tools. Joint distractors can be used to distract the calcaneus. If excessive varus or valgus occurs with application of a single distractor, adding a second on the opposite side (i.e., one medial and one lateral) may allow distraction without deformity. A transverse calcaneal traction pin can also accomplish joint distraction, and can be used to control hindfoot alignment. Schanz screws placed into the displaced talar body can assist with reduction of joint dislocations. Malleolar osteotomy, when required, may be performed using a number of techniques but requires a thin-bladed sagittal saw for the cortical cuts and a narrow osteotome to gently crack the cartilage at the level of the articular surface. Additional surgical tools that are useful to fine-tune the reduction include small screw-aided reduction clamps and small lamina spreaders, as well as a variety of fine-pointed reduction clamps. Kirschner wires are valuable for temporary fixation. Definitive fixation may include screws varying from 2 to 3.5 mm, plates of 2- or 2.4-mm diameter, and small-to-medium diameter cannulated screws (2 to 4.5 mm) (Table 60-2). 
 
Table 60-2
ORIF of Talar Neck and Body Fractures
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Table 60-2
ORIF of Talar Neck and Body Fractures
Preoperative Planning Checklist
  •  
    OR Table: Radiolucent
  •  
    Position/positioning aids: Supine, with varying sized bumps; drape limb from thigh down
  •  
    Fluoroscopy location: From contralateral side
  •  
    Equipment: Universal distractor (may require two) or external fixator
     
    Schanz screws
     
    Sterile calcaneal traction pin and bow
     
    Lamina spreaders
     
    Pointed reduction clamps
  •  
    Tourniquet: Either sterile or nonsterile
  •  
    Bone graft: Potentially useful for comminuted fractures
  •  
    Fixation: 2- to 3.5-mm screws
     
    Small plates (2 or 2.4 mm)
     
    Cannulated screws (4.5 mm or less)
X
Surgical Approaches.
Various surgical options exist to approach the talar neck fracture. Considerations for which approach to use include the degree and location of comminution, the potential need for malleolar osteotomy (for reduction and visualization purposes), and preservation of vascular supply. 
The anteromedial approach is perhaps the most commonly used. The incision is made directly over the talar neck and medial to the anterior tibial tendon. For fractures that extend more posteriorly into the talar body, the incision can be sited slightly posterior, midway between the anterior and posterior tibial tendons, to facilitate the creation of a medial malleolar osteotomy. When fractures of the talar neck are associated with malleolar fractures, the use of a medial incision will facilitate reduction and fixation of the medial malleolar fragment. In some cases, open reduction is difficult, and the talar body lies posteromedially with the deltoid ligament being the only remaining soft tissue attachment. In such instances, osteotomy of the malleolus preserves the deltoid ligament and facilitates reduction. Osteotomy of the malleolus may protect the only remaining source of vascularity for the talar body.158 For the more distal talar neck fracture, an incision just medial to the anterior tibial tendon is usually sufficient to provide direct access to the fracture site to visualize and manipulate both fragments. The anteromedial incision can be performed without exposing the anterior tibial tendon and leaving it within its sheath. Elevating thick subcutaneous and capsular tissue flaps from the anteromedial aspect of the tibia to the talonavicular joint facilitates exposure of the talar neck. 
The anterolateral approach is commonly used in addition to an anteromedial approach. It has been suggested that this may lessen the chance of damage to the blood supply of the talus, and it provides adequate exposure of the fracture.158 In many cases, a cortical fragment is visible at the anterolateral corner of the talar neck fracture at the anterior margin of the lateral process, upon which one may base an anatomic reduction. Exposure of the lateral aspect of the talus and the subtalar joint requires extra caution to avoid injury to the blood vessels of the sinus tarsi. 
A more direct lateral approach to the subtalar joint can be performed as an alternative to the anterolateral approach. It is often performed in conjunction with an anteromedial incision to facilitate exposure of the subtalar joint. This approach requires inferior mobilization of the extensor digitorum brevis muscle. Caution should be exercised around the sinus tarsi to protect the blood vessels. The direct lateral approach facilitates visualization of the subtalar joint especially in the case of comminuted fractures with extension into the subtalar joint. Like the anterolateral approach, visualization of the lateral process facilitates placement of a “shoulder screw” or lateral plate to stabilize the fracture. 
A posterior approach can be useful to facilitate reduction and screw fixation of the talar neck fracture. Directing the screws from posterior to anterior facilitates their placement perpendicular to the fracture line, thereby achieving compression without applying shear forces to the fracture. In some cases, a posteromedial approach is performed to facilitate reduction of a type III talar neck fracture. A malleolar osteotomy can be performed through this approach in cases where the deltoid ligament is intact and the talar body is rotated posteriorly between the posterior tibial tendon and the medial malleolus. Reduction can be very difficult and is facilitated through the use of a calcaneal traction pin or joint distractor in addition to the malleolar osteotomy. 
In other cases, a posterolateral approach can be used to facilitate lag screw fixation. Posterior screw fixation requires countersinking of the screws within the talus to protect the articular cartilage and maintain motion. With care, however, posterior screw fixation can be accomplished with minimal risk of surgical complications. 
Combined Approaches
Combined approaches are useful for talar neck fractures, especially those associated with extensive comminution.122 Judgment of an anatomic reduction can be difficult through a single approach. Combined approaches should be performed with caution to protect the tenuous blood supply to the talar body. The use of a combined approach facilitates preservation of the blood supply through any remaining dorsal neck vessels by avoiding excessive retraction on the anterior skin bridge. 
The utility of combined approaches has been demonstrated in recent large series of talar neck fractures. Thirty-eight out of 70 talar neck fracture-dislocations from one center were treated with dual approaches.173 Four patients from the group of 70 developed an early infection requiring reoperation. In another series of 102 talar neck fractures from a large trauma center, dual anteromedial and anterolateral approaches were used for 91 fractures. Of 60 fractures that were evaluated for complications, five developed skin complications of wound dehiscence and superficial or deep infections.204 
Percutaneous Fixation.
Percutaneous internal fixation can be used when a closed reduction has been successful at achieving an anatomic result (Fig. 60-19). Similarly, for a truly undisplaced talar neck fracture with anatomic alignment, percutaneous fixation can be used to facilitate early range of motion as opposed to cast treatment. Percutaneous fixation is most useful in noncomminuted fractures, as judging the reduction intraoperatively can be difficult when multiple fracture fragments are present. The fixation can be inserted from posteromedial, posterolateral, anteromedial, anterolateral, or through the lateral process of the talus. Depending upon the surgical plan, it may be useful to position the patient prone for posterior-to-anterior screw fixation, or on the side for posterolateral-based screw fixation. In any event, screws placed perpendicular to the fracture line are used to stabilize the fracture fragments and may be inserted with or without compression. Because of the proximity of the sural nerve posterolaterally and the neurovascular bundle posteromedially, it is worthwhile to perform careful blunt subcutaneous dissection to avoid neurovascular injury.52,151 Fernandez et al.53 reviewed a small series of patients treated with percutaneous internal fixation using a combination of antegrade and retrograde screw fixation. Three of the six patients reviewed had type I (undisplaced) fractures, while the other half were treated with closed reduction followed by percutaneous screw fixation. One of the six patients reviewed developed significant osteonecrosis.53 Potential advantages of percutaneous fixation include less surgical dissection, which may theoretically reduce the rates of osteonecrosis. 
Figure 60-19
Closed reduction followed by posterior-to-anterior screw fixation of a noncomminuted type II fracture.
 
The initial injury films are difficult to interpret but demonstrate a subtalar dislocation (A). An attempt at closed reduction partially reduced the subtalar joint but left residual subluxation (B). Formal closed reduction was accomplished in the operating room and stability was achieved with two posterior-to-anterior screws (C).
The initial injury films are difficult to interpret but demonstrate a subtalar dislocation (A). An attempt at closed reduction partially reduced the subtalar joint but left residual subluxation (B). Formal closed reduction was accomplished in the operating room and stability was achieved with two posterior-to-anterior screws (C).
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Figure 60-19
Closed reduction followed by posterior-to-anterior screw fixation of a noncomminuted type II fracture.
The initial injury films are difficult to interpret but demonstrate a subtalar dislocation (A). An attempt at closed reduction partially reduced the subtalar joint but left residual subluxation (B). Formal closed reduction was accomplished in the operating room and stability was achieved with two posterior-to-anterior screws (C).
The initial injury films are difficult to interpret but demonstrate a subtalar dislocation (A). An attempt at closed reduction partially reduced the subtalar joint but left residual subluxation (B). Formal closed reduction was accomplished in the operating room and stability was achieved with two posterior-to-anterior screws (C).
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Technique—Open Reduction and Internal Fixation of Talar Neck Fractures.
Exposure of the fracture, especially for complex fractures or dislocations, must be adequate to judge the reduction. In most cases, this requires combined medial and lateral incisions. A view of the medial talar neck from the medial malleolus to the talonavicular joint is useful to judge the reduction medially. On the lateral side, a view of the talus extending from the fibula to the talonavicular joint is used to judge the reduction. The majority of the posterior subtalar joint can be visualized and debrided from the lateral side. Dorsally, the neck vessels are protected as much as possible, so that only gentle retraction of the dorsal soft tissue is performed. Blunt dissection around the plantar aspect of the neck is performed to visualize the subtalar joint where necessary without adding additional vascular compromise. 
For comminuted fractures and fracture-dislocations, the use of a distractor is helpful to assist with reduction. Spanning the ankle joint with a medial distractor is a useful initial step. Pins may be placed in the medial tibia at the middiaphysis level, and the medial calcaneal tuberosity. A substantial distraction force may be required, especially for posteromedial dislocations, to assist with reduction of the dislocated talar body. When the ankle is unstable, for example when additional malleolar fractures are present, this may create a valgus deformity. In that situation, a second distractor can be applied laterally to provide additional distraction with less angular deformity. 
Reduction of the dislocated talar body can be incredibly challenging. In many cases, distraction of the tibiotalar joint combined with gentle pressure on the dislocated talar body is sufficient to reduce the talar body fragment into the mortise. If the distractors are supplying adequate traction, but the reduction remains difficult, then gaining control of the dislocated talar body is the next useful step. A Schanz pin may be inserted into the talar body through the existing anterior approaches if the talus can be visualized, or through an additional posteromedial incision. If direct manipulation of the talar body is still unsuccessful in achieving a reduction, consider a medial malleolar osteotomy. A malleolar osteotomy may allow a more gentle reduction compared to repeatedly trying to force the dislocated body into the mortise. It is important that a large enough “window” into the ankle mortise is created to simplify the reduction. Therefore, a large malleolar fragment should be created, and sufficient mobilization of it is required. Displacing the malleolar fragment sufficiently to allow a reduction often requires some posteromedial dissection, particularly of the posterior tibial tendon sheath, to allow the malleolar fragment to be mobilized on the intact deltoid ligament and provide free access to the medial ankle joint. Once the malleolus is osteotomized, additional joint distraction may again be applied. Although reduction of the dislocated talar body fragment may still be a challenge, some combination of these maneuvers should facilitate a successful reduction. Gonzalez et al.63 reported on three cases in which the use of a distractor and Schanz pin was unsuccessful at reducing the talus, but addition of a malleolar osteotomy allowed a gentle, nontraumatic reduction. 
At this point, fine-tuning of the reduction to achieve anatomic alignment is performed. Again, specialized reduction instruments may be helpful. Pointed reduction clamps are useful to realign and stabilize fragments in noncomminuted zones. Screw-aided reduction clamps and small distractors may be useful to realign comminuted segments. Reduction is best judged from a variety of angles, such that the use of two surgical approaches can be valuable at this point if not performed earlier in the procedure. Although the reduction may appear anatomic, the degree of malreduction can be striking when seen from another approach! 
Once the reduction appears anatomic, temporary fixation with Kirschner wires is achieved. The joint distractors can be removed and fluoroscopic confirmation of the reduction is performed. An anatomic reduction of the fracture, as well as the ankle and subtalar joints should be confirmed on AP, lateral, and Canale views. Definitive fixation can then be applied. 
Technique—Open Reduction and Internal Fixation of Talar Body Fractures.
Open reduction and internal fixation is the current standard treatment for displaced fractures of the talar body.1,50,116,198,205 In some cases, percutaneous techniques or arthroscopic techniques may be employed, with the potential benefit of preserving the blood supply.134,172 However, the goals of treatment should be respected, including anatomic restoration of alignment and achieving congruity of both the tibiotalar and subtalar joints. 
As with fractures of the talar neck, urgent treatment of dislocated talar body fractures is preferred. In open fractures or irreducible dislocations, treatment by necessity should be performed as early as possible. However, in the absence of joint subluxation or soft tissue impingement, definitive treatment can be delayed to facilitate improvement in the patient’s overall condition and to permit resolution of severe soft tissue swelling. 
Surgical approaches available include medial, lateral, and combined approaches. The anteromedial approach is commonly performed, as with talar neck fractures. It is generally wise to site the incision more posteriorly than usual to facilitate a medial malleolar osteotomy. Limited soft tissue dissection and retraction are useful to protect the blood supply. Finally, it is often not necessary to dissect into the talar head region, and the talonavicular joint capsule can often be preserved in its entirety. 
The anterolateral approach can be combined with the anteromedial exposure, or performed as a single approach. A fibular osteotomy may occasionally be necessary for exposure purposes, which may influence the placement of the incision. The use of combined anterolateral and anteromedial approaches is often required, especially in comminuted fractures and fractures with displacement of a complete coronal-plane fracture line. Isolated, noncomminuted, or sagittal plane fractures may be treated with a single incision either medial or lateral, depending upon the location of the primary fracture line.206 
In some cases, osteotomy of the medial or lateral malleolus is required to facilitate exposure. Vallier et al.205 utilized a medial malleolar osteotomy in 16 patients and a fibular osteotomy in three patients in the treatment of 57 fractures of the talar body. An osteotomy is most commonly required for displaced fractures of the posterior half of the talar body. Anterior fractures can frequently be visualized well without an osteotomy. As with talar neck fractures, reflecting the malleolus inferiorly may allow a more gentle reduction of the dislocated talar body, and preservation of the blood supply to the talar body via the deltoid ligament branches. 
When a malleolar osteotomy is required, predrilling and tapping before creating the osteotomy facilitates later reduction and screw fixation of the osteotomy.218 Various technique options for medial malleolar osteotomy include a simple oblique osteotomy, a chevron osteotomy, and biplanar osteotomy, depending upon surgeon preference.200 In any event, the osteotomy should include the entire malleolus to the level of the articular “corner” to ensure sufficient visualization and space for implant placement. 
Fixation Options.
Swanson et al.,190 using mathematical modeling, calculated that the theoretical maximum shear force across the talar neck during active motion was 1,129 N. Internal fixation of the talus should ideally be sufficient to withstand the forces involved with active motion until healing has occurred. 
Screws are commonly employed for fixation of talar neck and body fractures. They can be inserted from anterior to posterior or posterior to anterior. Posterior screw insertion provides the advantage of allowing screw placement perpendicular to the fracture line and, therefore, perhaps improving compression while avoiding shear with screw placement. In the mechanical study by Swanson et al.,190 posterior screw fixation was sufficient to withstand the theoretical shear forces of active motion. Cannulated screws are useful as the direction of screw travel requires careful fluoroscopic visualization and frequent redirecting of the guidewire is often necessary to achieve the desired screw position. Only a limited window posteriorly is available for correct screw insertion.45 Multiple cannulated screw sizes are available, and frequently a smaller screw is preferable. Thordarson et al.200 recommended the use of titanium screws to facilitate the later use of MRI scans in the assessment of osteonecrosis of the talus. Posteriorly inserted screws should be countersunk deep to the cartilage to avoid impingement. 
A number of anterior screw fixation options exist. In many cases, it is not possible to insert anterior screws perpendicular to the fracture line, especially on the medial talar neck. Removal of a small amount of cortical bone using a rongeur or a countersink may allow improved screw direction. Stabilization of comminuted fractures may be performed with the use of noncompressive or “buttress” screw techniques, whereas lag screw techniques can be employed for noncomminuted fractures. 
On the lateral talar neck, a shoulder of bone where the talar neck meets the lateral process adjacent to the subtalar joint is often an ideal location to place a compression screw and apply a small 2- or 2.4-mm plate. In many instances, the inferior segment of the lateral column of the talus fails in tension while the dorsal and medial aspects of the talar neck are comminuted. As a result, the inferior margin of the lateral column may therefore be noncomminuted even when the medial column is fragmented. On the margin of the lateral process, an anatomic reduction can often be visualized and a compressive screw inserted. This location allows screw placement from anterolateral to posteromedial in areas of the talus where the bone is denser, and compression along this axis does not cause varus malalignment (Fig. 60-20).45 
Figure 60-20
 
Intraoperative and postoperative views of a type II talus fracture treated with anterior-to-posterior screw fixation including a lateral shoulder screw. Anteroposterior (A), lateral (B), and Canale (C) views are shown following open reduction and internal fixation. Postoperative anteroposterior (D) and lateral (E) views 6 weeks later clearly demonstrate subchondral resorption of bone indicating vascularity of the talar body (Hawkins sign).
Intraoperative and postoperative views of a type II talus fracture treated with anterior-to-posterior screw fixation including a lateral shoulder screw. Anteroposterior (A), lateral (B), and Canale (C) views are shown following open reduction and internal fixation. Postoperative anteroposterior (D) and lateral (E) views 6 weeks later clearly demonstrate subchondral resorption of bone indicating vascularity of the talar body (Hawkins sign).
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Intraoperative and postoperative views of a type II talus fracture treated with anterior-to-posterior screw fixation including a lateral shoulder screw. Anteroposterior (A), lateral (B), and Canale (C) views are shown following open reduction and internal fixation. Postoperative anteroposterior (D) and lateral (E) views 6 weeks later clearly demonstrate subchondral resorption of bone indicating vascularity of the talar body (Hawkins sign).
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Figure 60-20
Intraoperative and postoperative views of a type II talus fracture treated with anterior-to-posterior screw fixation including a lateral shoulder screw. Anteroposterior (A), lateral (B), and Canale (C) views are shown following open reduction and internal fixation. Postoperative anteroposterior (D) and lateral (E) views 6 weeks later clearly demonstrate subchondral resorption of bone indicating vascularity of the talar body (Hawkins sign).
Intraoperative and postoperative views of a type II talus fracture treated with anterior-to-posterior screw fixation including a lateral shoulder screw. Anteroposterior (A), lateral (B), and Canale (C) views are shown following open reduction and internal fixation. Postoperative anteroposterior (D) and lateral (E) views 6 weeks later clearly demonstrate subchondral resorption of bone indicating vascularity of the talar body (Hawkins sign).
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Intraoperative and postoperative views of a type II talus fracture treated with anterior-to-posterior screw fixation including a lateral shoulder screw. Anteroposterior (A), lateral (B), and Canale (C) views are shown following open reduction and internal fixation. Postoperative anteroposterior (D) and lateral (E) views 6 weeks later clearly demonstrate subchondral resorption of bone indicating vascularity of the talar body (Hawkins sign).
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Bridging of comminuted medial or lateral columns of the talar neck may be required (Fig. 60-21). Use of plates around the talar neck fracture often requires some caution as the hardware can easily be prominent and cause impingement. Lateral plate placement is simpler than medial placement, as a large nonarticular region near the inferior margin of the lateral surface extends from the talar head cartilage to the lateral process. This area can often accommodate a four-hole, 2- or 2.4-mm contoured plate. Medially, less surface area is available but two- and three-hole plates may potentially be applied. Fleuriau Chateau et al.55 described a series of 23 patients with comminuted talar neck fractures treated with medial, lateral, or combined medial and lateral plate fixation. Four patients required hardware removal, but only two patients developed a malunion.55 The development of appropriate-sized implants has been critical to effective plate fixation in talar neck fractures. 
Figure 60-21
Anteroposterior (A) and lateral (B) intraoperative views of talus fracture fixation.
 
Periarticular lateral plate fixation is demonstrated, using a 2.4-mm plate extending from the anterior margin of the talar head to the lateral process. This plate is spanning a comminuted talar neck fracture with medial bone loss. An anteromedial screw was used to stabilize the medial column and a supplemental anterolateral screw was used to stabilize a large lateral process fragment.
Periarticular lateral plate fixation is demonstrated, using a 2.4-mm plate extending from the anterior margin of the talar head to the lateral process. This plate is spanning a comminuted talar neck fracture with medial bone loss. An anteromedial screw was used to stabilize the medial column and a supplemental anterolateral screw was used to stabilize a large lateral process fragment.
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Figure 60-21
Anteroposterior (A) and lateral (B) intraoperative views of talus fracture fixation.
Periarticular lateral plate fixation is demonstrated, using a 2.4-mm plate extending from the anterior margin of the talar head to the lateral process. This plate is spanning a comminuted talar neck fracture with medial bone loss. An anteromedial screw was used to stabilize the medial column and a supplemental anterolateral screw was used to stabilize a large lateral process fragment.
Periarticular lateral plate fixation is demonstrated, using a 2.4-mm plate extending from the anterior margin of the talar head to the lateral process. This plate is spanning a comminuted talar neck fracture with medial bone loss. An anteromedial screw was used to stabilize the medial column and a supplemental anterolateral screw was used to stabilize a large lateral process fragment.
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The biomechanics of plate fixation compared to screw fixation of talar neck fractures has been studied by Attiah et al.6 In a cadaver study of comminuted talar neck fractures, the stiffness and ultimate strength of an anteromedial blade plate was equivalent to posterior screw fixation. In both techniques, the strength exceeded the theoretical shear force across the talar neck and provided approximately 25% greater strength compared to anterior-to-posterior screw fixation.6 In a separate biomechanic study, Charlson et al.25 noted no mechanical advantage of lateral plate and medial screw fixation compared to posterior-to-anterior screw fixation. 
For talar body fractures, internal fixation can be performed for fragments of bone and cartilage large enough to stabilize. Depending upon the size of the fragment, cortical screws ranging from 2 to 4 mm in diameter can be used (Fig. 60-22). Care should be taken to avoid prominent hardware. Countersunk or headless screws are advantageous. Compression screw fixation may be used in noncomminuted fractures. Alternative fixation devices include Herbert screws,121 Kirschner wires, and threaded wires, all of which may be useful depending upon the size of the fragments to be stabilized. Small plates can also be used to span comminuted segments medially or laterally; in some cases a portion of the plate can be countersunk to lessen the risk of hardware impingement. 
Figure 60-22
 
A talar body and associated tibial plafond fracture treated with open reduction and internal fixation in an 82-year-old farmer. Coronal and reconstructed CT views demonstrate the talar body fracture with subtalar subluxation (A), plafond impaction and malleolar fracture (B), and talar body comminution (C). Three-month postoperative images demonstrate restoration of alignment (D–F) with multiple screw fixation. There is evidence of sclerosis of the talar body.
A talar body and associated tibial plafond fracture treated with open reduction and internal fixation in an 82-year-old farmer. Coronal and reconstructed CT views demonstrate the talar body fracture with subtalar subluxation (A), plafond impaction and malleolar fracture (B), and talar body comminution (C). Three-month postoperative images demonstrate restoration of alignment (D–F) with multiple screw fixation. There is evidence of sclerosis of the talar body.
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Figure 60-22
A talar body and associated tibial plafond fracture treated with open reduction and internal fixation in an 82-year-old farmer. Coronal and reconstructed CT views demonstrate the talar body fracture with subtalar subluxation (A), plafond impaction and malleolar fracture (B), and talar body comminution (C). Three-month postoperative images demonstrate restoration of alignment (D–F) with multiple screw fixation. There is evidence of sclerosis of the talar body.
A talar body and associated tibial plafond fracture treated with open reduction and internal fixation in an 82-year-old farmer. Coronal and reconstructed CT views demonstrate the talar body fracture with subtalar subluxation (A), plafond impaction and malleolar fracture (B), and talar body comminution (C). Three-month postoperative images demonstrate restoration of alignment (D–F) with multiple screw fixation. There is evidence of sclerosis of the talar body.
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Excision can be performed for small articular fragments which do not contribute to ankle or subtalar joint stability. Although no criteria exist for which fragments to stabilize or excise, the removal of small osteochondral fragments which do not contribute to joint stability seems to be well tolerated. 
In highly selected cases, primary arthrodesis may be the appropriate treatment for nonreconstructible fractures of the talar body. Only limited case reports are available in the literature, and these describe various techniques of arthrodesis. The length and alignment of the ankle and hindfoot should be retained (Fig. 60-23). Primary arthrodesis offers the potential advantage of earlier return to function compared to unsuccessful attempts at open reduction and internal fixation.28,30,73,157,165 However, most talar body fractures can be successfully treated with open reduction and internal fixation, such that primary arthrodesis is only rarely required. Experimental studies also exist with talar body replacement in the setting of severe crush fractures of the talus.74 
Figure 60-23
Treatment of a talar body fracture with primary subtalar arthrodesis in a 72-year-old woman with osteoporosis.
 
Anteroposterior and lateral radiographs at the time of the injury demonstrate subtalar subluxation (A, B) but the fracture, with associated comminution, is better demonstrated on CT scan (C). Treatment in this case included a primary subtalar arthrodesis with intercalary bone graft (D, E).
Anteroposterior and lateral radiographs at the time of the injury demonstrate subtalar subluxation (A, B) but the fracture, with associated comminution, is better demonstrated on CT scan (C). Treatment in this case included a primary subtalar arthrodesis with intercalary bone graft (D, E).
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Anteroposterior and lateral radiographs at the time of the injury demonstrate subtalar subluxation (A, B) but the fracture, with associated comminution, is better demonstrated on CT scan (C). Treatment in this case included a primary subtalar arthrodesis with intercalary bone graft (D, E).
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Figure 60-23
Treatment of a talar body fracture with primary subtalar arthrodesis in a 72-year-old woman with osteoporosis.
Anteroposterior and lateral radiographs at the time of the injury demonstrate subtalar subluxation (A, B) but the fracture, with associated comminution, is better demonstrated on CT scan (C). Treatment in this case included a primary subtalar arthrodesis with intercalary bone graft (D, E).
Anteroposterior and lateral radiographs at the time of the injury demonstrate subtalar subluxation (A, B) but the fracture, with associated comminution, is better demonstrated on CT scan (C). Treatment in this case included a primary subtalar arthrodesis with intercalary bone graft (D, E).
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Anteroposterior and lateral radiographs at the time of the injury demonstrate subtalar subluxation (A, B) but the fracture, with associated comminution, is better demonstrated on CT scan (C). Treatment in this case included a primary subtalar arthrodesis with intercalary bone graft (D, E).
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External fixation as definitive treatment is rarely indicated for talar neck and body fractures. The healing of the talar neck occurs slowly, by creeping substitution and primary bone healing as opposed to callus formation. Definitive external fixation is therefore required for a prolonged time. Temporizing external fixation has a role when talar neck fracture fixation is delayed, as a means of maintaining the reduction of the ankle and subtalar joints (Fig. 60-24). As well, external fixation can have a role in the case of highly contaminated open fractures to facilitate soft tissue management. Finally, external fixation has a role following talectomy as a temporary means to maintain length and alignment while further surgical intervention is being determined. 
Figure 60-24
Hawkins type III fracture treated with temporary spanning external fixation followed by definitive plate fixation.
 
Anteroposterior (A) and lateral (B) images with the external fixator in place demonstrate residual displacement of the talar neck fracture. A clinical photo 10 days postinjury demonstrates resolution of soft tissue swelling with persistent deformity (C). Anteroposterior and lateral radiographs (D, E) 8 weeks following definitive open reduction, plate fixation, and an intercalary tricortical iliac crest bone graft demonstrate maintenance of alignment but sclerosis of the talar body, suggesting avascularity. The dorsal plate fixation used in this case required countersinking of the plate at the articular margin to avoid restriction of tibiotalar motion.
Anteroposterior (A) and lateral (B) images with the external fixator in place demonstrate residual displacement of the talar neck fracture. A clinical photo 10 days postinjury demonstrates resolution of soft tissue swelling with persistent deformity (C). Anteroposterior and lateral radiographs (D, E) 8 weeks following definitive open reduction, plate fixation, and an intercalary tricortical iliac crest bone graft demonstrate maintenance of alignment but sclerosis of the talar body, suggesting avascularity. The dorsal plate fixation used in this case required countersinking of the plate at the articular margin to avoid restriction of tibiotalar motion.
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Anteroposterior (A) and lateral (B) images with the external fixator in place demonstrate residual displacement of the talar neck fracture. A clinical photo 10 days postinjury demonstrates resolution of soft tissue swelling with persistent deformity (C). Anteroposterior and lateral radiographs (D, E) 8 weeks following definitive open reduction, plate fixation, and an intercalary tricortical iliac crest bone graft demonstrate maintenance of alignment but sclerosis of the talar body, suggesting avascularity. The dorsal plate fixation used in this case required countersinking of the plate at the articular margin to avoid restriction of tibiotalar motion.
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Figure 60-24
Hawkins type III fracture treated with temporary spanning external fixation followed by definitive plate fixation.
Anteroposterior (A) and lateral (B) images with the external fixator in place demonstrate residual displacement of the talar neck fracture. A clinical photo 10 days postinjury demonstrates resolution of soft tissue swelling with persistent deformity (C). Anteroposterior and lateral radiographs (D, E) 8 weeks following definitive open reduction, plate fixation, and an intercalary tricortical iliac crest bone graft demonstrate maintenance of alignment but sclerosis of the talar body, suggesting avascularity. The dorsal plate fixation used in this case required countersinking of the plate at the articular margin to avoid restriction of tibiotalar motion.
Anteroposterior (A) and lateral (B) images with the external fixator in place demonstrate residual displacement of the talar neck fracture. A clinical photo 10 days postinjury demonstrates resolution of soft tissue swelling with persistent deformity (C). Anteroposterior and lateral radiographs (D, E) 8 weeks following definitive open reduction, plate fixation, and an intercalary tricortical iliac crest bone graft demonstrate maintenance of alignment but sclerosis of the talar body, suggesting avascularity. The dorsal plate fixation used in this case required countersinking of the plate at the articular margin to avoid restriction of tibiotalar motion.
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Anteroposterior (A) and lateral (B) images with the external fixator in place demonstrate residual displacement of the talar neck fracture. A clinical photo 10 days postinjury demonstrates resolution of soft tissue swelling with persistent deformity (C). Anteroposterior and lateral radiographs (D, E) 8 weeks following definitive open reduction, plate fixation, and an intercalary tricortical iliac crest bone graft demonstrate maintenance of alignment but sclerosis of the talar body, suggesting avascularity. The dorsal plate fixation used in this case required countersinking of the plate at the articular margin to avoid restriction of tibiotalar motion.
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Delayed Reduction

Delayed reduction is a treatment strategy which is not commonly employed for talar neck fractures. As a rule, prompt reduction and stabilization is preferred. However, it is sometimes a requirement due to multisystem injury or severe soft tissue compromise to delay reduction. Although prompt surgery is preferred, successful fracture healing can still be anticipated when surgery is delayed.116 Huang and Cheng83 reviewed nine patients treated between 4 months and 4 years after injury; all nine achieved union, although one patient developed osteonecrosis requiring ankle arthrodesis. Whether complications are more frequent following delayed surgery is unknown. Osteonecrosis may be more likely when surgery is delayed; however, most studies in which early versus late surgery were compared have been unable to detect a difference.50,116,173,204 

The Extruded Talus

In some cases of open talus fracture-dislocation, the talus is lost at the scene of the injury in which case there is no possibility of talar repair. In other situations, the bone is comminuted and contaminated to the point that replacement of the talus within the ankle mortise may simply not be feasible. The principles of talectomy include maintenance of length and alignment with the use of spanning external fixation, followed by tibiocalcaneal fusion. Isolated case series describe reasonable results following talectomy. Gunal et al.69 described a technique of talectomy in four patients, including lateral translation of the medial malleolus, and reported good results in three out of four patients. Kharwadkar et al.100 describe a case of primary talectomy for a patient with a type III talar neck fracture with full restoration of activity level and durable results after 15 years of follow-up. In general, however, results of talectomy are probably worse than the results of talus reduction and stabilization. 
In the case of a dislocated extruded talus or talar body, it is reasonable to attempt to replace it within the mortise, provided it is possible to achieve a clean surgical bed. Irrigation and debridement of the bone and the soft tissue is performed, followed by reimplantation of the clean talus. Internal or external fixation is required to stabilize the joints and the associated soft tissues and to facilitate wound care. Union can be obtained, even in a completely avascular talar body, by creeping substitution, although this may occur very slowly. It is not uncommon to see evidence of complete sclerosis of the talus 4 to 6 months after reimplantation, suggesting complete osteonecrosis. Smith et al.183 reviewed a large series of 27 patients with an extruded talus in whom the strategy of preserving and reimplanting the talus was followed. Nineteen patients attended review after a minimum of 1 year. Infection complicated treatment in only two of the patients, one of whom had a partial talar excision acutely. Secondary surgery was commonly necessary. Ultimately, however, revascularization occurred in most patients.183 Although osteonecrosis with collapse might be expected in most, if not all, patients with a reimplanted talus, it appears that some cases can successfully revascularize without collapse. Brewster and Maffulli16 reported on two cases of a reimplanted extruded talus which revascularized without collapse, whereas Gerken et al.59 described a case of talar extrusion in which MRI documented complete revascularization only after 1 year. As such, wherever practical, treatment of the completely dislocated talus includes replacement of the talus within the ankle mortise, followed by appropriate fixation, wound care, and rehabilitation to preserve the anatomy of the hindfoot (Table 60-3). 
 
Table 60-3
ORIF of Talar Neck and Body Fractures
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Table 60-3
ORIF of Talar Neck and Body Fractures
Surgical Steps
  •  
    Expose talus—two incisions
  •  
    Careful retraction—preserve soft tissue attachments
  •  
    Reduction of dislocated talar body fragment:
  •  
    Apply 1 or 2 medium distractors across ankle joint
  •  
    Schanz pin into body fragment
  •  
    Medial malleolar osteotomy
  •  
    Reduction of neck fracture and articular fragments
  •  
    Provisional stabilization with Kirschner wires
  •  
    Fluoroscopic confirmation: AP, lateral, Canale views
  •  
    Definitive fixation of fracture:
  •  
    Compression screws
  •  
    Noncompression screws
  •  
    Plate fixation
  •  
    Wound closure
  •  
    Splint in neutral dorsiflexion
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Operative Treatment of Talar Head and Process Fractures

Displaced talar head fractures and those associated with joint subluxation or dislocation require open reduction and internal fixation (Fig. 60-25). Small comminuted segments can be excised, but larger fragments can usually be reduced and stabilized with small or minifragment screws. The surgical approach can be dorsomedial, dorsolateral, or combined depending upon where the displaced fragments are located. It is best to make an effort to preserve whatever portions of the talonavicular capsular and ligamentous supports are intact. Displaced fragments are reduced and stabilized, usually with screws ranging from 2 to 3.5 mm in diameter. Bone grafting is occasionally necessary. Following surgery, patients are placed in a short leg non–weight-bearing splint until wound healing occurs. Early motion may be instituted depending upon the stability of the fixation and the talonavicular joint. In most instances, the talonavicular joint is stable following surgery, and mobilization in a removable splint may begin after wound healing. 
Figure 60-25
Talar head fracture treated with primary open reduction and internal fixation.
 
Axial and coronal CT images demonstrate the fracture (A) and associated subtalar subluxation (B) better than plain radiographs (C). Open reduction and internal fixation was performed with compression screws (D).
Axial and coronal CT images demonstrate the fracture (A) and associated subtalar subluxation (B) better than plain radiographs (C). Open reduction and internal fixation was performed with compression screws (D).
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Figure 60-25
Talar head fracture treated with primary open reduction and internal fixation.
Axial and coronal CT images demonstrate the fracture (A) and associated subtalar subluxation (B) better than plain radiographs (C). Open reduction and internal fixation was performed with compression screws (D).
Axial and coronal CT images demonstrate the fracture (A) and associated subtalar subluxation (B) better than plain radiographs (C). Open reduction and internal fixation was performed with compression screws (D).
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Displaced lateral process fractures with large fragments may be treated with open reduction and internal fixation (Fig. 60-26). Preoperative CT is helpful in determining if fragments are large enough to fix or will require excision. The amount of comminution is often worse than is apparent on plain radiographs. For comminuted fractures, primary excision of fragments is indicated to avoid the later development of arthritic changes in the subtalar joint.79 Langer et al.110 studied the effect of excision of a 1-cm fragment of the lateral process on ankle and subtalar stability. Although slight increases in anterior translation, talar tilt, and subtalar motion were noted, the increases were well below the traditional radiographic thresholds used to define instability. The authors concluded that excision of a 1-cm3 fragment should not cause ankle or subtalar instability.110 Open reduction or fragment excision may be performed through a direct lateral approach using an incision over the sinus tarsi. When open reduction is performed, screw fixation can often be accomplished with the screw inserted from the tip of the process and extending posteriorly and superiorly into the talar body. Screws ranging from 2 to 2.7 mm in diameter are typically sufficient for fixation of lateral process fractures. 
Figure 60-26
A lateral process fracture demonstrated on an anteroposterior radiograph of the ankle (A) and confirmed by CT (B).
 
Open reduction and internal fixation was performed with a cancellous screw and Kirschner wire (C, D).
Open reduction and internal fixation was performed with a cancellous screw and Kirschner wire (C, D).
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Figure 60-26
A lateral process fracture demonstrated on an anteroposterior radiograph of the ankle (A) and confirmed by CT (B).
Open reduction and internal fixation was performed with a cancellous screw and Kirschner wire (C, D).
Open reduction and internal fixation was performed with a cancellous screw and Kirschner wire (C, D).
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Fractures of the medial or lateral tubercle of the posterior process can be treated with open reduction and internal fixation, or more commonly excision. Often surgery is performed on a delayed basis to treat a nonunion, in which case excision is a reliable option to treat persistent pain. Kanbe et al.92 treated two patients with medial tubercle fractures with open reduction and internal fixation. In both cases, the fragment was found to be much larger than initially suspected.92 Cedell21 surgically excised three persistently symptomatic ununited fragments. Stefko et al.187 excised a malunited fragment to relieve a secondary tarsal tunnel syndrome. Kim et al.102 reported on two patients diagnosed early who were successfully managed with cast immobilization, and three patients who presented late who were successfully managed with fragment excision. In general, excision of ununited or malunited fragments seems to relieve local irritative symptoms in patients who present with posteromedial ankle pain secondary to a posterior tubercle avulsion. 

Postoperative Care

Following surgery, patients are initially splinted with the foot in a plantigrade position until the surgical incisions have healed. Once the skin has healed, the patient can begin gentle range-of-motion exercises with the use of a removable cast brace. Restricted weight bearing is usually continued for approximately 3 months following the injury. 
It is worthwhile to counsel patients about the risks of osteonecrosis and delayed union or nonunion of the talus fracture. Revascularization can be seen on plain radiographs with Hawkins sign (see below) noted at the 6- to 8-week mark postoperatively, and followed at subsequent visits. Alternatively, MRI may be used to determine the status of the perfusion of the talus. Union can be difficult to judge using plain radiographs, and CT scanning is often helpful to define when union has been achieved. 

Potential Pitfalls and Preventative Measures

Talar neck and body fractures are relatively rare, so thoughtful preparation prior to surgical treatment is essential. Do not rush into surgery without adequate preparation. CT scanning can give valuable information regarding the appropriate surgical approach and whether a malleolar osteotomy is required. It is reasonable to delay surgery until soft tissue swelling has settled, provided the peritalar joints are not dislocated. 
Appropriate care should be taken to avoid “iatrogenic osteonecrosis.” Avoid stripping the medial and plantar aspects of the talus, where the primary blood supply enters, and avoid stripping any more of the dorsal neck than is necessary. 
Achieving a reduction of the dislocated talar body is often the first and most difficult pitfall during the operative procedure. The use of a distractor, a Schanz pin, and very often, a malleolar osteotomy is helpful to avoid this particular difficulty. Consider a malleolar osteotomy as a better option compared to a forceful reduction. In talar body fractures, the osteotomy is only required when the fracture line extends posterior to the midpoint of the talus. Visualization and fixation in more anterior fractures can usually be achieved with plantarflexion of the ankle. 
During surgery, judging the alignment of the reduction can similarly be challenging, particularly in comminuted fractures. Visualizing the fracture through dual approaches is essential to avoid this pitfall. The degree of misalignment judged to be “anatomic” through a single approach can be striking when observed from a different viewpoint. As well, understanding the radiographic images is helpful to judge the overall alignment. A Canale view to visualize the medial aspect of the talar neck can rule out varus deformity. Further pronating the foot will bring the lateral column of the talus into profile to check for any degree of valgus misalignment. Misalignment of the talar neck is often associated with subtalar incongruity, which can be viewed on a proper lateral radiograph. 
Dealing with small comminuted fragments of the talus can be troublesome. In general, removing fragments too small to offer solid screw purchase seems to be well tolerated without causing ankle or subtalar instability. It may, however, be worthwhile to bone graft large defects particularly in the dorsomedial and dorsolateral talar neck region to provide some additional stability and facilitate healing. 
Impinging hardware can be a frustrating outcome for both the patient and the surgeon. When placing hardware, ensure that periarticular screws are countersunk adequately. Plates must be small enough and correctly placed to avoid impingement; both medial and lateral plates can impinge against the navicular or malleoli. Take the ankle and subtalar joint through a full range of motion prior to wound closure, and use fluoroscopy to prove no impingement is occurring. In some cases it is useful to save images of the ankle fully dorsiflexed and fully plantarflexed; these can be valuable tools for patients and allied health care workers during the postoperative period. 
During the postoperative phase, it can be difficult to decide when a patient should be permitted to bear weight. As a general rule, weight bearing does not seem to change the progress of revascularization, such that the development of osteonecrosis probably cannot be meaningfully prevented. In some cases, however, where union is slow to occur, unrestricted weight bearing should likely be delayed to avoid problems with implant breakage or loosening and misalignment (Table 60-4). 
 
Table 60-4
Talus Fractures: Potential Pitfalls and Preventions
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Table 60-4
Talus Fractures: Potential Pitfalls and Preventions
Pitfalls Preventions
Difficult reduction of the dislocated talus Joint distractor(s)
Schanz pin
Malleolar osteotomy
Fracture misalignment Dual approaches
Intraoperative fluoroscopic views
Bone defects Excise small fragments and graft as necessary
Impinging hardware Countersink articular screws
Careful plate application
Range joints prior to closure
Determining weight-bearing status Restrict until union
X

Outcomes of Fractures and Dislocations of the Talus

The outcome after fractures of the talar neck and body can be excellent in the absence of complications. In longer-term follow-up, two-thirds of patients with talar neck fractures reported good or excellent functional outcomes between 2 and 10 years after injury.173 Unfortunately, despite advances in surgical timing, techniques, and devices, complications following talar neck and body fractures remain common.20,31,32,50,76,108,157,158,161,173,192,193,204 
For fractures of the talar neck, the frequency of complications seems to be particularly dependent upon the severity of the initial injury, such that Hawkins’ classification continues to be very relevant not only as a descriptor of the fracture, but also as a predictor of osteonecrosis and outcome. More recently, fracture comminution has also been noted to be a predictor of outcome and complications.173,204 The rate of secondary surgery after talar fractures is high; in one study, approximately half of the patients with talar neck fractures required secondary surgery within 10 years.173 The most common secondary procedures were subtalar or triple arthrodesis, followed by ankle arthrodesis; and the most common reason to perform a secondary procedure was posttraumatic arthritis. Posttraumatic arthritis was most likely in patients with comminution, Hawkins type III or IV injuries, and patients with ipsilateral extremity injuries.173 
Talar body fractures may also lead to complications, including osteonecrosis, malunion, and arthritis.30,94,125,132 Although improvements in surgical techniques and fixation implants may decrease the incidence of complications, recent reports continue to demonstrate very high rates of osteonecrosis and arthritis. In one study, 88% of the patients had radiographic evidence of osteonecrosis and/or posttraumatic arthritis at a follow-up of 33 months.205 Other complications include flexor tendon entrapment in scar tissue,146 superficial and deep wound infections, and skin necrosis. Lindvall et al.116 reported very similar complication rates and outcomes between talar neck and talar body fractures. Unfortunately, disability, chronic pain, and impairment are common sequelae of talar body fractures. Functional outcome scores demonstrate substantial disability even when compared to patients with other hindfoot injuries.51,205 

Management of Adverse Outcomes and Complications of Fractures and Dislocations of the Talus

Infection and Skin Necrosis

The skin of the ankle and foot is fragile and easily injured. Infection can be a problem in both closed and open fractures of the talus. Deep infection is, without question, a devastating complication. The older literature notes the severity of this complication. Syme,191 in 1848, described a series of 11 deaths in 13 patients with open fracture-dislocations of the talus, all resulting from infection. He recommended a transtibial amputation as appropriate treatment. Other more recent reports have also noted the dangers of deep infection.20,60,152 
Once a deep infection is established, treatment becomes extremely challenging. The avascular body of the talus acts as a large necrotic sequestrum. Early in the postoperative course, thorough irrigation and debridement combined with hardware exchange or removal may successfully treat the infection. For an established infection combined with nonunion, aggressive surgical debridement, including partial or total talectomy, may be necessary to achieve control of the infection. Excision of the necrotic talus combined with delayed tibiocalcaneal fusion can still achieve reasonable results in terms of hindfoot alignment and stability.20,125,152,158 

Osteonecrosis

The reported incidence of osteonecrosis after talar neck fracture varies in the literature, but is generally low in type I fractures with a risk of 0% to 13%. The risk increases to 20% to 50% in type II fractures and to over 80% in type III fractures in some reports. The incidence of osteonecrosis is somewhat dependent upon the diagnostic criteria used but in general, correlates with the Hawkins classification.128 The overall incidence of osteonecrosis is between 21% and 58%, making it a common complication of talar neck fractures.20,76 The risk of osteonecrosis seems to be lower in more recent reports.173,204 This may be related to improved surgical techniques for preserving blood supply to the talus, to better implants that provide greater stability to facilitate revascularization, or simply because of different diagnostic criteria. 
Osteonecrosis following talar body fracture is similarly common. Combined fractures of the talar neck and body may be more predisposed to osteonecrosis.205 Talar body fractures with associated fractures of the malleoli may have a lower risk of osteonecrosis, as the combination of osseous injuries may preserve ligamentous attachments, thereby preserving the blood supply to the body fragments.138 
The radiographic diagnosis of osteonecrosis is made when the avascular talar body demonstrates increased density compared with the surrounding vascularized bone, which is undergoing disuse atrophy. Later, as revascularization occurs, there can be partial or complete collapse of the subchondral bone, narrowing of the joint space, and occasionally fragmentation of the talar body. The “Hawkins sign” is a well-described radiographic indication of viability of the talar body (Fig. 60-20). As noted by Hawkins, “The time to recognize the presence of avascular necrosis is between the sixth and the eighth week after the fracture-dislocation. By this time, if the patient has been nonweight bearing, diffuse atrophy is evident by roentgenogram in the bones of the foot in the distal part of the tibia. An anteroposterior roentgenogram of the ankle made with the foot out of the plaster cast, reveals the presence or absence of subchondral atrophy in the dome of the talus. Subchondral atrophy excludes the diagnosis of avascular necrosis.”76,145 
Hawkins sign, when present, excludes osteonecrosis and therefore is highly specific. However, the absence of Hawkins sign does not imply osteonecrosis is a certainty. Furthermore, the extent of involvement of the talar body is variable.113 In some cases, partial osteonecrosis is noted, particularly in type II fractures. In many type III injuries, the entire talar body blood supply is disrupted resulting in osteonecrosis of the entire talar body. Tehranzadeh et al.196 described three cases of a partial Hawkins sign following fractures of the talus and suggested the partial Hawkins sign may correlate with disruption of end arteries within the body of the talus. The reliability of Hawkins sign was recently studied in 31 patients with displaced talar fractures. No patient who developed osteonecrosis had a positive Hawkins sign; however, the absence of Hawkins sign was not universally associated with the development of osteonecrosis.197 
MRI is the preferred modality to evaluate osteonecrosis. Bone scanning with a pinhole collimator160 can be effective but has largely been replaced by MRI which can be used as early as 3 weeks postinjury. It defines not only the presence but also the extent of osteonecrosis, as well as the condition of the articular cartilage (Fig. 60-27).1,182,198 
Figure 60-27
 
This T1-weighted MRI scan was obtained 6 months after a talar fracture-dislocation and demonstrates osteonecrosis of the talar body. The region of osteonecrosis corresponds to the distribution of the artery of the tarsal canal. The scan also demonstrates arthritis of the talonavicular and subtalar joints, subluxation of the subtalar joint, and extensive fluid accumulation around the talus in keeping with a diagnosis of infection.
This T1-weighted MRI scan was obtained 6 months after a talar fracture-dislocation and demonstrates osteonecrosis of the talar body. The region of osteonecrosis corresponds to the distribution of the artery of the tarsal canal. The scan also demonstrates arthritis of the talonavicular and subtalar joints, subluxation of the subtalar joint, and extensive fluid accumulation around the talus in keeping with a diagnosis of infection.
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Figure 60-27
This T1-weighted MRI scan was obtained 6 months after a talar fracture-dislocation and demonstrates osteonecrosis of the talar body. The region of osteonecrosis corresponds to the distribution of the artery of the tarsal canal. The scan also demonstrates arthritis of the talonavicular and subtalar joints, subluxation of the subtalar joint, and extensive fluid accumulation around the talus in keeping with a diagnosis of infection.
This T1-weighted MRI scan was obtained 6 months after a talar fracture-dislocation and demonstrates osteonecrosis of the talar body. The region of osteonecrosis corresponds to the distribution of the artery of the tarsal canal. The scan also demonstrates arthritis of the talonavicular and subtalar joints, subluxation of the subtalar joint, and extensive fluid accumulation around the talus in keeping with a diagnosis of infection.
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Once osteonecrosis is diagnosed, the prognosis and best treatment remain a source of controversy. Osteonecrosis does not necessarily preclude a reasonable outcome. Union can occur in the presence of osteonecrosis, provided the fixation is stable. Prolonged periods of nonweight bearing have been recommended because the talus is revascularized slowly via creeping substitution of necrotic bone with vascularized bone. This process may require up to 36 months.124,125 Such a long duration of nonweight bearing is unpredictable, impractical, and difficult for patients. One alternative solution is the use of a patellar tendon bearing ankle-foot orthosis with an articulated ankle. Saltzman et al.171 evaluated the effect of patellar tendon bracing in Charcot arthropathy and determined that force transmission to the hindfoot was reduced by 37%. The brace also reduces varus and valgus stresses to the hindfoot while allowing some ankle dorsiflexion/plantarflexion to nourish the articular cartilage of the talar dome. 
Operative options to deal with the osteonecrotic talus are numerous. Some authors have recommended immediate surgical treatment. Options have included primary triple arthrodesis,125 total talectomy with tibiocalcaneal fusion,168 talectomy alone,15 subtalar fusion,105,106 pantalar fusion,67 and primary tibiotalar fusion. In most cases, a more conservative approach in which osteonecrosis of the talus can be treated expectantly with preservation of the talar body fragment is followed. Anatomic reduction and fixation of the fracture are maintained, and arthrodesis is not indicated unless the talus collapses or arthritis develops. 
Selected case reports and small series in the literature describe successful efforts to revascularize the necrotic talus. Hussl et al.84 describe a technique using vascularized corticocancellous iliac crest bone graft to prevent collapse. Mont et al.137 performed a variation of core decompression of the talus in 17 ankles with symptomatic nontraumatic osteonecrosis without collapse. Once the chondral surface has collapsed, treatment is directed toward relief of pain symptoms and restoration of alignment. In unusual instances, collapse of the entire talar body can occur while leaving a relatively congruent ankle joint. The function of these ankles is not normal, but may be acceptable to the patient. Collapse of large segments of the talar body is usually associated with severe hindfoot malalignment and irregularities in the articular cartilage such that arthrodesis is commonly necessary to relieve symptoms. 
For patients with collapse of the talar dome and the development of symptomatic arthritis of the ankle joint, ankle arthrodesis is indicated. Tibiocalcaneal arthrodesis and the Blair or modified Blair fusion have been found effective. Blair12 described a technique of ankle fusion in 1943 specifically designed to treat osteonecrosis of the talus. He recommended excision of the avascular talar body and placement of a sliding corticocancellous graft from the anterior distal tibia into the residual, viable talar head and neck (Fig. 60-28). Modifications of this technique include screw fixation of the sliding anterior distal tibial graft, suggested by Lionberger et al.,117 and retention of the talar body. Authors such as Morris et al.139 and Dennis and Tullos36 have reviewed case series and recommend the modified Blair fusion as a satisfactory reconstructive treatment after severe talar injuries. Recently, Shrivastava et al.181 presented a series of eight patients who underwent primary Blair tibiotalar arthrodesis for Hawkins type III fractures of the talar neck, most of whom presented on a delayed basis. Although results were not uniformly good in this challenging group of patients, six of the eight patients were described as achieving a good result.181 Benefits of the Blair fusion include a normal appearance of the foot, minimal shortening, and potential retention of some subtalar function.73 
Figure 60-28
Blair fusion.
 
Schematic drawing showing the anterolateral incision (A), sliding graft from the distal tibia (B), and the sliding graft embedded into the talar neck and head fragment (C). Note the space left by removal of the talar body. (Blair HC. Comminuted fractures and fracture dislocations of the body of the astragalus: Operative treatment. Am J Surg. 1943;59:38.) Radiographs (D, E) demonstrate a healed modified Blair fusion 2 years following a type III talar neck fracture with the sliding graft incorporated. The talar body has been retained and remains sclerotic, but appears to be healed to the distal tibia.
Schematic drawing showing the anterolateral incision (A), sliding graft from the distal tibia (B), and the sliding graft embedded into the talar neck and head fragment (C). Note the space left by removal of the talar body. (Blair HC. Comminuted fractures and fracture dislocations of the body of the astragalus: Operative treatment. Am J Surg. 1943;59:38.) Radiographs (D, E) demonstrate a healed modified Blair fusion 2 years following a type III talar neck fracture with the sliding graft incorporated. The talar body has been retained and remains sclerotic, but appears to be healed to the distal tibia.
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Schematic drawing showing the anterolateral incision (A), sliding graft from the distal tibia (B), and the sliding graft embedded into the talar neck and head fragment (C). Note the space left by removal of the talar body. (Blair HC. Comminuted fractures and fracture dislocations of the body of the astragalus: Operative treatment. Am J Surg. 1943;59:38.) Radiographs (D, E) demonstrate a healed modified Blair fusion 2 years following a type III talar neck fracture with the sliding graft incorporated. The talar body has been retained and remains sclerotic, but appears to be healed to the distal tibia.
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Figure 60-28
Blair fusion.
Schematic drawing showing the anterolateral incision (A), sliding graft from the distal tibia (B), and the sliding graft embedded into the talar neck and head fragment (C). Note the space left by removal of the talar body. (Blair HC. Comminuted fractures and fracture dislocations of the body of the astragalus: Operative treatment. Am J Surg. 1943;59:38.) Radiographs (D, E) demonstrate a healed modified Blair fusion 2 years following a type III talar neck fracture with the sliding graft incorporated. The talar body has been retained and remains sclerotic, but appears to be healed to the distal tibia.
Schematic drawing showing the anterolateral incision (A), sliding graft from the distal tibia (B), and the sliding graft embedded into the talar neck and head fragment (C). Note the space left by removal of the talar body. (Blair HC. Comminuted fractures and fracture dislocations of the body of the astragalus: Operative treatment. Am J Surg. 1943;59:38.) Radiographs (D, E) demonstrate a healed modified Blair fusion 2 years following a type III talar neck fracture with the sliding graft incorporated. The talar body has been retained and remains sclerotic, but appears to be healed to the distal tibia.
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Schematic drawing showing the anterolateral incision (A), sliding graft from the distal tibia (B), and the sliding graft embedded into the talar neck and head fragment (C). Note the space left by removal of the talar body. (Blair HC. Comminuted fractures and fracture dislocations of the body of the astragalus: Operative treatment. Am J Surg. 1943;59:38.) Radiographs (D, E) demonstrate a healed modified Blair fusion 2 years following a type III talar neck fracture with the sliding graft incorporated. The talar body has been retained and remains sclerotic, but appears to be healed to the distal tibia.
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Tibiocalcaneal arthrodesis is an alternative option in which fusion of the calcaneus to the distal tibia is performed. Intercalary graft can facilitate a hindfoot arthrodesis.168 Results were noted to be superior to talectomy by Canale and Kelly.20 Proponents of this procedure note that the fusion of the tibia to the calcaneus may provide more stability compared to the sliding graft technique. The use of intercalary material is required if the length and appearance of the hindfoot is to be maintained. 
In summary, osteonecrosis of the talus is a relatively common and significant complication after talar neck fractures. The radiographic appearance of osteonecrosis does not universally imply permanent disability. Many patients with osteonecrosis do not require further surgery, and the talus may uneventfully revascularize. Current recommendations are, first, to reconstruct the talus at the time of injury with an anatomic reduction and stable fixation of the fracture. Weight bearing in the presence of osteonecrosis can be facilitated, potentially with a patellar tendon bearing orthosis. Further surgical intervention should be directed to alleviating symptoms where necessary, often including a modification of the Blair fusion or a tibiocalcaneal arthrodesis. 

Malunion

Anatomic reduction is essential to achieving a good result following talar neck fractures. In one series of 46 patients, Peterson et al.161 achieved better results in type III fractures compared to type II fractures. The critical variable was the adequacy of the initial reduction, with an exact reduction being achieved more frequently in patients with type III fractures.161 Miller130 felt that “the ability to obtain and maintain an anatomic reduction (closed or open) is the most important factor in predicting good results.” Hawkins76 noted that a good to excellent result is the expected outcome following anatomic reduction of a talus fracture-dislocation not complicated by osteonecrosis. 
The development of a malunion can occur in several ways. Obtaining an anatomic reduction can be difficult to assess, particularly when using closed means. The use of lateral radiographs and a Canale view are helpful to achieving an adequate reduction. The fixation devices used should be carefully selected to avoid creating a malreduction and to provide adequate stability. For example, in fractures with medial comminution, the use of medial column compression screw fixation will inevitably cause compression, leading to a varus malunion. Full weight bearing in patients without solid fracture union may gradually lead to a malunion, in which case the first overt sign may be implant failure. Malunion can occur with dorsal displacement of the distal fragment, resulting in limitation of dorsiflexion and a painful gait;20 or a varus malunion, usually accompanied by a supination deformity of the foot. Daniels et al.33 in a cadaver study, noted that removal of a wedge of bone from the medial talar neck resulted in varus deformity, internal rotation of the hindfoot, adduction of the forefoot, and loss of subtalar motion. 
The quality of internal fixation influences the development of malunion. Canale and Kelly20 reported that 14 of 30 patients with type II fractures treated in a cast developed a varus malunion. More recently, in a study of patients with high-energy fractures treated with screw fixation, a varus hindfoot alignment was observed clinically in 40% of the patients.173 The use of plate fixation may be associated with a lower incidence of malunion,55,204 although there are currently no studies comparing the two techniques. Recognition of a malunion is important but can be difficult. A recent study compared the accuracy of a variety of imaging techniques to detect talar neck malunion. Chan et al.22 noted that investigators underestimated the degree of malunion of talar neck fractures independent of the imaging technique used, particularly for rotational misalignment. Translational deformities were best measured by CT.22 
Treatment of malunion varies. In the case of a dorsal malunion, resection of the dorsal beak may be satisfactory.19,20 Often, however, reconstruction of the malunion is more complicated. Options include osteotomies of the calcaneus, midfoot, or talar neck,135 and triple arthrodesis for severe malalignment associated with degenerative changes. A recent series of 10 patients with malunion or displaced nonunions reported good results by reconstruction of the talar alignment and revision fixation in all patients, without the need for arthrodesis of the adjacent joints.167 
Malunion after talar neck fracture is likely generally underdiagnosed, but clinically important. Varus malunion results in pain, subtalar stiffness, and excessive weight bearing on the lateral side of the foot. Over time, the soft tissue structures become contracted (Fig. 60-29). Subtalar or triple arthrodesis is often required to achieve alignment and deal with secondary degenerative changes. 
Figure 60-29
Reconstruction of talar neck malunion.
 
A: Preoperative clinical photograph demonstrates varus deformity. B, C: Postoperative clinical photographs following tendo Achillis lengthening and a calcaneal osteotomy demonstrate restoration of neutral alignment.
A: Preoperative clinical photograph demonstrates varus deformity. B, C: Postoperative clinical photographs following tendo Achillis lengthening and a calcaneal osteotomy demonstrate restoration of neutral alignment.
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Figure 60-29
Reconstruction of talar neck malunion.
A: Preoperative clinical photograph demonstrates varus deformity. B, C: Postoperative clinical photographs following tendo Achillis lengthening and a calcaneal osteotomy demonstrate restoration of neutral alignment.
A: Preoperative clinical photograph demonstrates varus deformity. B, C: Postoperative clinical photographs following tendo Achillis lengthening and a calcaneal osteotomy demonstrate restoration of neutral alignment.
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Posttraumatic Arthritis

Posttraumatic arthritis of the ankle or subtalar joint can occur after fractures of the talus. Subtalar arthritis is particularly common after talar neck fracture.173 Osteoarthritis may develop in the presence or absence of osteonecrosis. Causes of osteoarthritis include osteonecrosis, cartilage damage, joint stiffness, and misalignment. Substantial damage to the articular cartilage of the talus is common with fracture-dislocations. In addition, prolonged immobilization can lead to arthrofibrosis, impaired cartilage nutrition, and secondary osteoarthritis. The combination of severe cartilage injury, osteonecrosis, and immobilization ensures a high likelihood of arthritis in the peritalar joints. Even undisplaced talar neck fractures lead to decreased motion in both the ankle and subtalar joints, a prolonged time off of work, and a substantial incidence of unsatisfactory results.32 
Posttraumatic degenerative changes develop radiographically in the subtalar joint in 46% to 69% of patients after talar neck fracture.20,50,118,173,177,192 Following talar body fracture, degenerative changes are similarly common. Radiographic findings suggesting tibiotalar arthritis were noted in 65% of patients, and subtalar joint changes were noted in 35% of patients in one review of talar body fractures.205 All of the patients with open talar body fractures developed arthritis. These authors also noted that functional outcomes were worse in patients with radiographic signs of osteoarthritis compared to patients without arthritis in their series. 
Hindfoot symptoms are not always solely due to arthritis. It is frequently necessary to localize the source of symptoms to the arthritic joint before proceeding to surgical intervention. Selective joint infiltration with local anesthetic may be used to localize the source of pain. An injection of local anesthetic into the symptomatic joint which provides complete pain relief can be a useful prelude to arthrodesis. 
Once pain has been localized to the arthritic joints, treatment can begin. Anti-inflammatory medications, protected weight bearing, and bracing may be helpful. Failure of these conservative measures leads to surgical intervention, usually arthrodesis of the involved joints. Subtalar and ankle fusion in the presence of a talar neck fracture can be performed using standard techniques, provided the talar body is perfused. Alternatively, modified Blair fusion techniques may be helpful. Similarly, if the talar body is well perfused, ankle arthroplasty may be considered for selected cases of posttraumatic arthritis; however, the use of ankle replacement as a treatment option for posttraumatic arthritis in young, active patients remains a source of considerable controversy (Table 60-5).28 
 
Table 60-5
Talus Neck and Body Fractures
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Table 60-5
Talus Neck and Body Fractures
Common Adverse Outcomes and Complications
Stiffness
Infection:
  •  
    Early infection
  •  
    Delayed infection (may have avascular talar body sequestrum)
Osteonecrosis:
Delayed Union or Nonunion
Malunion
  •  
    Dorsal beak
  •  
    Varus
  •  
    Supination deformity
Posttraumatic Arthritis
  •  
    Tibiotalar joint
  •  
    Subtalar joint
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Outcomes and Complications of Talar Head and Process Fractures

Displaced fractures of the talar head and processes are prone to the development of nonunion and degenerative arthritis (Fig. 60-30).43 Nonunion of talar head fractures is relatively uncommon, but talonavicular arthritis is frequent. The treatment options for symptomatic talonavicular arthritis include the use of longitudinal arch supports with increased arch rigidity or a long steel shank in the shoe. If conservative measures fail, arthrodesis of the talonavicular joint or triple arthrodesis may be indicated.42 
Figure 60-30
Missed talar head fracture with talonavicular subluxation.
 
Lateral radiograph demonstrates the talonavicular subluxation (A) confirmed by CT scan (B) and intraoperative visualization. Following osteotomy and reduction (C), the talonavicular joint is congruent.
Lateral radiograph demonstrates the talonavicular subluxation (A) confirmed by CT scan (B) and intraoperative visualization. Following osteotomy and reduction (C), the talonavicular joint is congruent.
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Figure 60-30
Missed talar head fracture with talonavicular subluxation.
Lateral radiograph demonstrates the talonavicular subluxation (A) confirmed by CT scan (B) and intraoperative visualization. Following osteotomy and reduction (C), the talonavicular joint is congruent.
Lateral radiograph demonstrates the talonavicular subluxation (A) confirmed by CT scan (B) and intraoperative visualization. Following osteotomy and reduction (C), the talonavicular joint is congruent.
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Malunion of talar head fragments may also occur. In particular, dorsomedial fragments which remain displaced may result in residual talonavicular joint subluxation. Verhaar209 reported on a case of late talonavicular subluxation secondary to malunion. Anatomic restoration of alignment of the talar head fragment eliminated the subluxation. 
The literature, with respect to outcome of lateral process fractures following treatment, is limited to small case series.27,29,39,54,75,99,106,131,141 Pain in the region of the subtalar joint seems to be common following fractures of the lateral process, especially when the diagnosis is delayed. Nonunion of unreduced fractures and residual malalignment of the subtalar joint can cause persistent symptoms.39,75,141 Several authors have noted that earlier treatment may be associated with better results. In one review of the literature, it was noted that earlier treatment resulted in a low rate of nonunion and generally good outcome.201 Heckman and McLean,79 in a review of nine patients, found the best results when patients were diagnosed and treated early compared to a high proportion of patients with pain when treatment was delayed. Therefore, whether casting, fragment excision, or open reduction and internal fixation is necessary, it seems that the proposed treatment is best performed early. 
Earlier recognition of lateral process fractures may be leading to more favorable outcomes. For example, von Knoch et al.210 noted generally favorable outcomes in 23 snowboarders with lateral process fractures. Sixty-five percent of the patients regained their preinjury activity level, and outcome scores were excellent in virtually all patients. Those with nondisplaced fractures fared slightly better compared to patients with displaced fractures.210 Similar results were reported by Valderrabano et al.203 with 16 of 20 snowboarders with lateral process fractures returning to full sports activities. In both of these series, degenerative changes were noted in the subtalar joint in several patients approximately 3 years after the injury. 
Nonunion of lateral and posterior process fractures probably occurs more frequently than is commonly recognized. Patients complain of pain with plantarflexion or pain with physical activity, and there may be restriction of ankle and subtalar joint motion. In addition to nonunion, symptoms referable to the flexor hallucis longus tendon may develop. Partial rupture or tenosynovitis of the tendon may occur, and is usually noted in athletes such as soccer players or ballet dancers. Inokuchi and Usami87 reported a case of complete rupture of the flexor hallucis longus tendon following a nonunion of a Shepherd fracture, requiring tendon grafting to restore tendon function. 
Making the diagnosis can be difficult: If the posterior process fracture fragment has developed a rounded appearance on radiographs, distinguishing an ununited fragment from an os trigonum can be challenging. In addition to the fragment, radiographs may show degenerative changes adjacent to the fragment and in the subtalar joint. Bone scan may demonstrate increased uptake in the area of the fragment; however, an MRI scan will demonstrate the nonunion as well as edema around the fragment suggestive of inflammation. 
Treatment of nonunions is usually restricted to excision of ununited fragments. Attempts at obtaining union of established nonunions are unlikely to succeed. Excision of posterior process fragments may be accomplished via a posterolateral208 or posteromedial approach,216 and usually achieves relief of pain and improved motion.102,123,211 Nonunions associated with subtalar joint subluxation frequently develop subtalar arthritis requiring arthrodesis.154 

Author’s Preferred Treatment for Fractures and Dislocations of the Talus

 
 

Surgery is indicated for all displaced talar neck and body fractures. Good-quality ankle radiographs and CT scanning forms the basis for accurate diagnosis and surgical planning. Undisplaced, isolated Hawkins type I fractures can be treated successfully with immobilization in a cast. I prefer to use percutaneous stabilization for type I fractures in multiply injured patients. If cast treatment is used, a below-knee non–weight-bearing cast is applied initially. Following cast application, repeat plain radiographs and CT confirms maintenance of a perfect reduction. If any displacement is noted, the classification of the fracture should be reconsidered and open reduction and internal fixation performed. If cast treatment is successful at maintaining the reduction, the patient is asked to remain nonweight bearing for 6 weeks or until there is some radiographic evidence of healing. Next, the patient is converted to a removable brace to begin active range-of-motion exercises. CT is useful at multiple intervals: To initially confirm that the fracture is undisplaced, to confirm that the reduction has been maintained, and to confirm that union has occurred. Patients are warned against excessive weight-bearing activity until union appears to be complete.

 

Displaced talar neck and body fractures associated with joint dislocations require prompt reduction. When possible, immediate closed or open reduction of the dislocated joints is performed. An attempt at a closed reduction can be performed under adequate anesthesia. Type III or IV fractures are usually not successfully reduced with closed techniques. If an anatomic closed reduction is accomplished, and the fracture is noncomminuted, internal fixation is inserted using percutaneous techniques to achieve stability and facilitate early mobilization. When percutaneous stabilization is performed, it is important to confirm that the reduction is anatomic, usually via CT scan. An open reduction should be performed if there is any doubt about the quality of the reduction. I typically perform percutaneous reduction with the patient in the prone position and use a minimum of two 4-mm cannulated screws, inserted from posterolateral or posteromedial. The preoperative CT scan, especially the reconstructed views, is used to characterize the obliquity of the fracture and define the ideal screw trajectory perpendicular to the fracture line. A small incision and careful blunt dissection is used to protect the associated neurovascular structures at risk, and to ensure that the screws are sufficiently countersunk.

 

When open reduction and internal fixation is performed, I prefer an anteromedial approach to visualize the medial aspect of the talar neck as a standard initial approach. A slightly more posterior placement of the skin incision, halfway between the tibialis anterior and posterior tendons, facilitates a medial malleolar osteotomy, when required. In the large majority of fractures, a second approach is performed to confirm an anatomic reduction. An incision extending from the tip of the fibula to the fourth metatarsal base facilitates visualization of the lateral aspect of the fracture and placement of hardware. The lateral side is often less comminuted, and thus, one’s ability to judge the reduction may be improved. The lateral approach is performed in all except the most simple of fracture patterns. Dissection around the sinus tarsi and across the dorsal talar neck is kept to a minimum, and overzealous retraction is avoided, to maintain any soft tissue attachments.

 

Once the incisions have been made and visualization achieved, accomplishing a reduction is sometimes challenging. A medial distractor combined with a Schanz pin into the talar body is useful for type II fractures, whereas combined medial and lateral distractors and a medial malleolar osteotomy are useful for type III or IV fractures. Reflection of the medial malleolus distally facilitates a much gentler closed reduction compared to direct manipulation and is more likely to preserve the talar blood supply via the deltoid ligament. In talar body fractures, the decision whether a malleolar osteotomy is required is based upon the location of the primary fracture line. Fractures that involve the anterior talar body or are associated with malleolar fractures do not require an osteotomy. I perform an osteotomy for those fractures with involvement of the posterior half of the talar body. Usually the osteotomy is medial, but a fibular osteotomy can aid in fractures with lateral side comminution. It is helpful to predrill the screw fixation holes for the osteotomy before making the cut. I prefer a simple oblique medial malleolar osteotomy, angled approximately 60 degrees to the longitudinal axis of the tibia, intersecting with the articular margin 1 to 2 mm lateral to the medial edge of the articular surface of the plafond. An osteotome is used to complete the cut through the articular surface. This technique seems to facilitate good interdigitation of the fragments at the articular surface; 2.7- or 3.5-mm position screws are then used for fixation to avoid overcompression at the nonarticular margin. Thordarson et al.200 and Alexander and Watson3 describe a step-cut medial malleolar osteotomy for exposure of the talar body which results in uncomplicated healing.

 

Once the joints are reduced, the fracture margins are debrided of comminution. In many cases, extensive comminution is noted, especially involving the subtalar joint. Thorough visualization of the subtalar joint aids to ensure that all loose fragments and debris have been removed. The fracture reduction can then be fine-tuned until an anatomic alignment is achieved.

 

With regards to fixation, I prefer to use compression screw techniques to address a noncomminuted talar neck fracture and 2-mm plates or their equivalent to address the comminuted medial or lateral column. Rarely, dual plates are necessary for highly comminuted talar neck fractures. Additional screws can then be inserted perpendicular to the primary fracture line for additional stability. The size of screws used depends upon the size of the talar fragments. Usually 2.7-mm screws are used to stabilize the primary fracture fragments, with smaller 2- or 2.4-mm screws for comminuted fragments. Two-mm plates are easiest to contour to the medial or lateral column. Plate placement close to the plantar surface of the talus allows a longer plate to be used. On the lateral side, a four-hole plate beginning at the talar head cartilage can often be contoured to extend to the anterior surface of the lateral process. Screw insertion should be directed perpendicular to the plate. Good fixation through the plate is usually achieved (Fig. 60-21). Medially, less surface area is available for plate placement, and options may be restricted to a two- or three-hole plate.

 

When the lateral column is reduced, placement of a screw along the lateral shoulder of bone allows an ideal screw insertion point and facilitates compression across the fracture line. The anterolateral shoulder screw is useful to avoid malalignment and facilitates compression of the fracture on the tension side.

 

Fixation of talar body fractures is typically easier from the medial side, where an area devoid of cartilage exists at the margin of the deep deltoid ligament insertion on the talus. When this is impossible or additional fracture fragments require fixation, countersunk intra-articular screws or headless screws are required.

 

Bone defects larger than 1 cm3 are usually grafted primarily. The distal tibia provides a reasonable source of cancellous bone. A simple trephination technique into the metaphysis allows removal of approximately 2 to 3 cc of bone, which can then be impacted into the defect. Larger defects are treated with iliac crest or allograft bone.

 

Intraoperative fluoroscopic imaging is accomplished by placing the imaging intensifier on the opposite side of the operating table, with free draping of the limb. Imaging aids to confirm an anatomic reduction, and to ensure that hardware is appropriately placed. Lateral views in full dorsiflexion and plantarflexion after fixation can rule out ankle joint impingement. A Canale view confirms the talar reduction, and can rule out talonavicular joint impingement.

 

Once the reduction is confirmed and the fixation stable, a standard layered wound closure is performed. Following surgery, patients are splinted with the foot in a neutral position for 2 weeks. At that point, compliant patients can begin gentle range-of-motion exercises with the use of a removable cast brace. Multiply injured or noncompliant patients may require a longer period of immobilization. Patients are asked to remain strictly nonweight bearing for the first 6 weeks after surgery, and longer if the fracture is comminuted or bone defects are present. Some degree of restricted weight bearing is usually continued for approximately 3 months following the injury, or until union is confirmed (Fig. 60-31).

 
Figure 60-31
Author’s preferred treatment algorithm for talar neck and body fractures.
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Dislocations of and Around the Talus

Subluxation and dislocation of the talus can occur in conjunction with major talus fractures, as described above. However, dislocations can also occur with no associated bony injury or with relatively minimal appearing fractures. These injuries can be considered in two broad categories: Subtalar dislocation and total talar dislocation. 

Subtalar Dislocation

Subtalar dislocation, also known as peritalar dislocation,7 refers to the simultaneous dislocation of the distal articulations of the talus at the talocalcaneal and talonavicular joints. Although first described by Judcy91 and Dufaurets41 in 1811, the combined dislocations are uncommon, and the clinical literature related to subtalar dislocation is limited. Smith184 noted only seven subtalar dislocations in a review of 535 dislocations of all types. Leitner115 noted only 42 among 4,215 dislocations. Fifteen percent of all talar injuries in Pennal’s157 series were subtalar dislocations. Most commonly, the injuries occur in young adult males, although Bibbo et al.9 noted 36% of subtalar dislocations in their series of 25 patients occurred in patients over 40 years of age. 

Anatomy and Classification

Subtalar dislocation can occur in any direction. Significant deformity is always present. Medial dislocations are thought to be more common, comprising up to 85% of subtalar dislocations (Fig. 60-32).35,65,80,136,164 The calcaneus, with the rest of the foot, is displaced medially while the talar head is prominent in the dorsolateral aspect of the foot. The navicular is medial and sometimes dorsal to the talar head and neck. Lateral dislocation occurs less often. In a lateral dislocation, the calcaneus is displaced lateral to the talus and the talar head is prominent medially (Fig. 60-33). The navicular lies lateral to the talar neck. Rarely, a subtalar dislocation is reported to occur in an anterior or posterior direction, but these are usually associated with medial or lateral displacement as well.90,107,164 The direction of subtalar dislocation has important effects with respect to management and outcome. The method of reduction is different for each type of injury. In addition, lateral dislocations are associated with higher-energy mechanisms and a worse long-term prognosis compared to medial subtalar dislocations. 
Figure 60-32
In this medial subtalar dislocation, the head of the talus (A) is palpable on the dorsum of the foot.
 
The heel (B) is displaced medially.
 
(Buckingham WW Jr. Subtalar dislocation of the foot. J Trauma. 1973;13:754.)
The heel (B) is displaced medially.
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Figure 60-32
In this medial subtalar dislocation, the head of the talus (A) is palpable on the dorsum of the foot.
The heel (B) is displaced medially.
(Buckingham WW Jr. Subtalar dislocation of the foot. J Trauma. 1973;13:754.)
The heel (B) is displaced medially.
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(Buckingham WW Jr. Subtalar dislocation of the foot. J Trauma. 1973;13:757.)
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Figure 60-33
In this lateral subtalar dislocation, the head of the talus is prominent medially while the rest of the foot is dislocated laterally.
(Buckingham WW Jr. Subtalar dislocation of the foot. J Trauma. 1973;13:757.)
(Buckingham WW Jr. Subtalar dislocation of the foot. J Trauma. 1973;13:757.)
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Mechanism of Injury

Inversion of the foot results in a medial subtalar dislocation, whereas eversion produces a lateral subtalar dislocation. The calcaneonavicular ligament resists disruption,17 while the inversion or eversion force is dissipated through the weaker talonavicular and talocalcaneal ligaments such that the calcaneus, navicular, and all distal bones of the foot are displaced as an unit either medially or laterally. With a medial subtalar dislocation, the sustentaculum tali acts as a fulcrum about which the foot rotates to lever apart the talus and calcaneus; in the lateral dislocation, the foot pivots about the anterior process of the calcaneus, again causing the talus and calcaneus to separate.188 

High Versus Low-Energy Injuries

Subtalar dislocations can result from either high-energy or low-energy mechanisms. The distinction is important because outcome has been correlated with the severity of the initial injury. In the series of Bibbo et al.,9 high-energy mechanisms such as motor vehicle trauma and falls from height accounted for 68% of subtalar dislocations. Other common mechanisms include sports injuries, usually related to a fall from a jumping height. Grantham65 coined the term “basketball foot” to describe a medial subtalar dislocation because four of the five patients in his series sustained the injury on the hardwood. Usually, the dislocation occurs when landing from a rebound. Open subtalar dislocations and lateral subtalar dislocations are more common with a high-energy mechanism. Medial dislocations are more common, suggesting that the forces required to produce it are less than those required to produce a lateral dislocation. 
High-energy subtalar dislocations may be associated with other injuries, either regional or involving other body systems. One series described associated foot and ankle injuries in 88% of patients with subtalar dislocations.9 Regional fractures include talus, ankle, calcaneus, navicular, cuboid, cuneiform, and metatarsal fractures.26 Osteochondral shearing injuries to the articular surface of the talus, the calcaneus, or the navicular are common. These injuries occurred in 45% of patients in one large series, and were difficult to detect on plain radiographs.35 Injuries remote from the foot and ankle may occur as well. In a series of subtalar dislocations from a major Level I trauma center, other musculoskeletal injuries occurred in 48% of the patients, and 12% of the patients had injuries to the head, abdomen, or chest.9 

Signs and Symptoms

Subtalar dislocations present with an impressive amount of deformity. The medial dislocation has been referred to as an “acquired clubfoot” whereas the lateral dislocation has previously been described as an “acquired flatfoot”.188 In addition, many of the injuries are open, particularly when associated with a high-energy mechanism. Up to 40% of subtalar dislocations may present with an open wound.127 The head of the talus may protrude through the open wound in a lateral dislocation. In closed dislocations, the skin is usually distorted and markedly tented over the prominent head of the talus. Swelling occurs rapidly and may mask the bony deformity. An evaluation for neurovascular impairment should be performed prior to and following reduction of the dislocation. 
Figure 60-34
Medial subtalar dislocation.
 
The head of the talus is directed superior to the navicular.
The head of the talus is directed superior to the navicular.
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Figure 60-34
Medial subtalar dislocation.
The head of the talus is directed superior to the navicular.
The head of the talus is directed superior to the navicular.
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Figure 60-35
Radiographs of a lateral subtalar dislocation.
 
Note that the head of the talus is displaced inferior to the navicular.
 
(Buckingham WW Jr. Subtalar dislocation of the foot. J Trauma. 1973;13:758.)
Note that the head of the talus is displaced inferior to the navicular.
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Figure 60-35
Radiographs of a lateral subtalar dislocation.
Note that the head of the talus is displaced inferior to the navicular.
(Buckingham WW Jr. Subtalar dislocation of the foot. J Trauma. 1973;13:758.)
Note that the head of the talus is displaced inferior to the navicular.
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Radiographic Findings

Radiographs of a subtalar dislocation may be difficult to interpret. The severity of the deformity makes it difficult to obtain true anteroposterior and lateral images of the foot, and standard ankle radiographs do not reveal the foot pathology.68 The relationship between the talus and tibia and fibula may be normal or demonstrate positional talar tilt only because the point of injury is distal to the ankle joint. 
The anteroposterior view of the foot demonstrates the talonavicular dislocation. 
The absence of the talar head within the “cup” of the navicular is an important diagnostic key. On the lateral projection, the head of the talus usually lies superior to the navicular and cuboid for a medial dislocation and appears to be displaced inferior in a lateral dislocation (Figs. 60-34 and 60-35). Usually, interpretation of the plain radiographs provides enough information to determine the direction of the dislocation, such that the physician can proceed with an attempt at reduction. However, plain radiographs should be interpreted with caution. Associated fractures can be missed on plain radiographs, and postreduction films may not be adequate in all cases to determine whether residual subluxation is present. 
CT scanning determines whether associated fractures are present and is sensitive enough to rule out talocalcaneal subluxation. Bohay and Manoli13 described four cases of subtalar dislocation with associated fractures or residual subluxation not documented on plain radiographs. Merchan127 reported associated fractures in 64% of his series of 39 cases, and Bibbo et al.9 reported associated injuries to the foot and ankle in 88% of patients. In another study, in which a CT scan was performed in all cases, the CT identified additional injuries missed on initial plain radiographs in all patients, and in 44% of the patients, new information gathered by CT dictated a change in treatment.10 

Treatment

Closed Reduction.
All subtalar dislocations require a gentle and timely reduction. In most cases, reduction can be accomplished closed. Often, the injury presents with skin tenting such that a prompt reduction will reduce the possibility of skin necrosis. Open peritalar dislocations require a formal irrigation and debridement in addition to the reduction followed by wound closure.49 
The principles of closed reduction include, first, the provision of adequate relaxation and sedation. A forceful manipulation may be necessary to accomplish the reduction, and patients are often disturbed by the sight of their markedly deformed extremity, such that general anesthesia may be required to achieve sufficient relaxation. Second, the tension on the Achilles tendon should be relaxed by flexing the knee. Next, longitudinal traction on the foot is applied with countertraction on the leg. 
Accentuation of the deformity is often necessary to “unlock” the calcaneus. Inversion is therefore applied initially for a medial dislocation, and eversion for a lateral dislocation. Once the calcaneus is unlocked, reversal of the deformity can be applied. Successful reduction is usually accompanied by a satisfying clunk. 
Digital pressure over the head of the talus can also be applied to aid in reduction. However, it should be applied with caution. The calcaneus is ideally unlocked with inline traction and accentuation of the deformity before digital pressure is applied. Although digital pressure over the talar head can aid in the reduction, it may also cause further skin necrosis and potentially displace an osteochondral fracture. 
Once the reduction is accomplished, it should be confirmed by clinical examination and radiographs. On clinical examination, the foot should demonstrate a restoration of normal alignment and range of motion of the subtalar and midtarsal joints. Plain radiographs confirm the reduction and should be closely inspected for associated fractures that may have been missed on the radiographs of the distorted foot. In many cases, a subtalar dislocation is stable following closed reduction. This is particularly the case when there are no associated osteochondral or other fractures. Clinical assessment of stability can be performed following closed reduction. If the dislocation is clinically stable, no internal fixation is necessary. A CT scan should be performed following reduction to confirm that no displaced intra-articular fragments are present, and to confirm that a congruent joint reduction has been obtained. The foot can then be temporarily immobilized in a short leg posterior splint. For stable reductions, immobilization until edema has settled and pain controlled is adequate. Less than 2 weeks of immobilization may be all that is necessary. 
Following a short period of immobilization, physical therapy is instituted to regain subtalar and midtarsal mobility. The outcome following simple dislocations treated with closed reduction seems to be favorable.35 In a series of 30 patients with a closed isolated subtalar dislocation, de Palma et al.37 reported that only three patients went on to require subtalar arthrodesis after a minimum of 5 years of follow-up. Seventy percent of patients scored either good or excellent on joint-specific functional outcome measures.37 Recurrent dislocations are reported but are uncommon,89,112,217 and therefore it is reasonable to proceed with early mobilization to avoid potential problems related to joint stiffness. 
Closed reduction is unsuccessful in some patients. In most series, the need for open reduction seems to be associated with higher-energy subtalar dislocations. In some series, as few as 10% of patients with medial dislocations and 15% to 20% of lateral subtalar dislocations required open reduction.70,80,115,194 Garofalo et al.57 reviewed a series of 18 patients with peritalar dislocations in whom no open reductions were required. Some series, particularly from trauma centers, have noted the need for open reduction to be more common, with up to 32% of patients requiring open reduction.9 
A variety of bone and soft tissue structures may become entrapped, resulting in a block to closed reduction. These impediments require open manipulation or release to facilitate reduction. With medial dislocations, the talar head can become trapped by the capsule of the talonavicular joint, the extensor retinaculum or the extensor tendons, or the extensor digitorum brevis muscle. Heck et al.77 studied the irreducible medial subtalar dislocation in a cadaver model. Entrapment of the talar head in the extensor retinaculum, talonavicular impaction, and impingement of the deep peroneal nerve and dorsalis pedis branches between the talus and navicular were implicated as causes of irreducible subtalar dislocation.77 Talonavicular impaction is often implicated as an obstruction to closed reduction (Fig. 60-36). The extreme medial displacement of the foot at the moment of injury is followed by recoil toward the normal position, causing the lateral edge of the navicular to impinge on the talar head. An impaction fracture is produced and the articular surfaces become interlocked. 
Figure 60-36
 
Line drawing of a medial subtalar dislocation, irreducible by closed means, due to impaction of the talus and navicular with interlocking of the articular surfaces. (Buckingham WW Jr. Subtalar dislocation of the foot. J Trauma. 1973;13:757.)
Line drawing of a medial subtalar dislocation, irreducible by closed means, due to impaction of the talus and navicular with interlocking of the articular surfaces. (Buckingham WW Jr. Subtalar dislocation of the foot. J Trauma. 1973;13:757.)
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Figure 60-36
Line drawing of a medial subtalar dislocation, irreducible by closed means, due to impaction of the talus and navicular with interlocking of the articular surfaces. (Buckingham WW Jr. Subtalar dislocation of the foot. J Trauma. 1973;13:757.)
Line drawing of a medial subtalar dislocation, irreducible by closed means, due to impaction of the talus and navicular with interlocking of the articular surfaces. (Buckingham WW Jr. Subtalar dislocation of the foot. J Trauma. 1973;13:757.)
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Articular surface impaction may also block the reduction of a lateral subtalar dislocation. The posterior tibial tendon has also been implicated as a barrier to closed reduction, as it can be displaced and wrapped around the head of the talus (Fig. 60-37). Woodruff et al.215 presented a case in which the musculotendinous junction of the tibialis posterior muscle allowed the extreme tendon excursion required to displace the tendon around the talar head. Alternatively, the flexor retinaculum may be torn such that the talar head can buttonhole between the flexor tendons.215 
Figure 60-37
Lateral subtalar dislocation with interposed posterior tibial tendon preventing closed reduction.
 
(Adapted from Leitner B. Obstacles to reduction in subtalar dislocations. J Bone Joint Surg. 1954;36(2):299–306.)
(Adapted from Leitner B. Obstacles to reduction in subtalar dislocations. J Bone Joint Surg. 1954;36(2):299–306.)
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Figure 60-37
Lateral subtalar dislocation with interposed posterior tibial tendon preventing closed reduction.
(Adapted from Leitner B. Obstacles to reduction in subtalar dislocations. J Bone Joint Surg. 1954;36(2):299–306.)
(Adapted from Leitner B. Obstacles to reduction in subtalar dislocations. J Bone Joint Surg. 1954;36(2):299–306.)
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Open Reduction.
Open reduction, when necessary, is performed through a longitudinal anteromedial incision. This approach allows access to the structures that may be incarcerating the head of the talus and allows visualization of an interlocked impaction fracture of the talus and navicular. With a lateral peritalar dislocation, the incision may be sited more medially to facilitate manipulation of the posterior tibial tendon. 
It is usually possible to gently displace the offending bone or soft tissue that is preventing closed reduction. Osteochondral shear fractures may block reduction, and fragments should be removed if small and nonstructural.119 It is often possible to repair displaced bone fragments with small screws or to elevate and bone graft impacted fragments. Entrapped soft tissue can usually be gently distracted and the reduction achieved (Fig. 60-38). However, the extensor retinaculum in particular may require transection to facilitate a reduction. 
Figure 60-38
 
Clinical photograph of a complex lateral peritalar dislocation with entrapment of the peroneal tendons between the calcaneus and cuboid. Removal of the peroneal tendons was required to facilitate reduction. (Adapted from Leitner B. Obstacles to reduction in subtalar dislocations. J Bone Joint Surg. 1954;36(2):299–306.)
Clinical photograph of a complex lateral peritalar dislocation with entrapment of the peroneal tendons between the calcaneus and cuboid. Removal of the peroneal tendons was required to facilitate reduction. (Adapted from Leitner B. Obstacles to reduction in subtalar dislocations. J Bone Joint Surg. 1954;36(2):299–306.)
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Figure 60-38
Clinical photograph of a complex lateral peritalar dislocation with entrapment of the peroneal tendons between the calcaneus and cuboid. Removal of the peroneal tendons was required to facilitate reduction. (Adapted from Leitner B. Obstacles to reduction in subtalar dislocations. J Bone Joint Surg. 1954;36(2):299–306.)
Clinical photograph of a complex lateral peritalar dislocation with entrapment of the peroneal tendons between the calcaneus and cuboid. Removal of the peroneal tendons was required to facilitate reduction. (Adapted from Leitner B. Obstacles to reduction in subtalar dislocations. J Bone Joint Surg. 1954;36(2):299–306.)
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With a lateral dislocation, the posterior tibial tendon when entrapped may present a substantial barrier, even to open reduction, as it may become very firmly entrapped. Extreme varus and plantarflexion of the hindfoot is necessary to relax the tendon, along with extending the incision through the flexor retinaculum. Even so, in some cases it has been necessary to transect the posterior tibial tendon to achieve a reduction.112 This should be done as a last resort only, and it should be repaired and protected following reduction. 
Following reduction, the peritalar dislocation should be assessed for congruency radiographically and for stability. When an open reduction is required because of soft tissue interposition, the reduction is usually stable. However, if large or multiple bone fragments required removal, stability may be less than ideal. In this case, internal fixation with smooth wires across the subtalar and talonavicular joints may be necessary to maintain the reduction.57 Following 4 to 6 weeks of immobilization, the internal fixation can be removed and weight bearing and active physiotherapy instituted. 

Author’s Preferred Treatment for Subtalar Dislocation

 
 

Subtalar dislocations without associated fractures are initially treated by an attempted closed reduction. Once reduced, the dislocation is usually stable and no internal fixation is necessary. I obtain a CT scan for all subtalar dislocations once the reduction has been attempted. If the closed reduction has been unsuccessful, CT scan provides useful information regarding any bony obstacles to reduction. Following reduction, the CT scan confirms that an anatomic reduction has been achieved and is also useful to assess whether associated osteochondral fractures require further intervention. Occasionally, osteochondral fragments not visible on plain radiographs lie directly within the subtalar joint and require operative removal to achieve an anatomic articular reduction. Alternatively, bone fragments can be avulsed with ligamentous attachments (i.e., from the tip of the fibula or lateral process of talus) in which case a short period of immobilization (up to 4 weeks) may be helpful to reduce pain, allow some provisional healing, and reduce swelling before beginning mobilization exercises.

 

When a closed reduction has been successful for a simple dislocation, I prefer the use of a well-padded splint until swelling has receded, followed by the application of a short leg removable brace. Patients are encouraged to actively move the ankle, subtalar, and midtarsal joints after approximately 2 weeks but are advised to continue to wear the brace while weight bearing for approximately 4 to 6 weeks. As a result, the goals of early motion are achieved while maintaining protection from sudden and unexpected inversion and eversion forces.

 

Open reduction is necessary when closed reduction does not achieve a congruent joint. I have found the need for open reduction to be more common than the 10% to 15% often quoted in the literature. I perform an anteromedial approach in most cases and try to avoid incisions through any region of impending or potential skin necrosis (usually localized directly over the talar head). Impaction fractures are usually treated by disimpaction and reduction, followed by elevation and grafting of the fragments. Soft tissue entrapments are carefully inspected for interposed neurovascular structures, then distracted and released as necessary. The posterior tibial tendon should be protected as much as possible in a lateral dislocation, but despite efforts to preserve the tendon, it may not function normally after the reduction, leading to problems later. Smooth Steinmann pins are sometimes necessary to immobilize the hindfoot when the reduction is not stable because of associated bone fragments. When internal fixation is necessary, I immobilize the foot until the pins are removed (usually 6 weeks later) and then recommend active motion physiotherapy.

 
Prognosis and Complications
 

Subtalar dislocations have a wide variance in terms of their prognosis. Uncomplicated subtalar dislocations, stable following a closed reduction, have an excellent prognosis with minimal symptoms at long-term follow-up. Limitation of subtalar joint motion is a consistent abnormal finding and may be associated with pain when walking on uneven ground or pain with weather changes.17,65,112,184 Perugia et al.159 reported on 45 patients with subtalar dislocations followed for a mean of 7.5 years in whom the mean ankle and hindfoot functional outcome score was in the good to excellent range. Only one patient in their study required a subtalar arthrodesis.159

 

Most reviews, however, report a mixture of outcomes following subtalar dislocation. Garofalo et al.57 followed 18 patients for 10 years and reported that 44% had fair or poor results. Ruiz Valdivieso et al.170 followed 17 patients for a mean of 7.9 years. Their results were good in only 6 of 17, and fair or poor in the remaining 11.170 Bibbo et al.9 studied 25 patients from a Level I trauma center. Of the 18 patients who were available for review at a mean of 5 years, 89% demonstrated radiographic changes of ankle arthritis, 89% demonstrated subtalar arthritis, and 72% demonstrated midfoot arthritis. Functional outcome scores were much lower than in the study of Perugia et al.,159 and eight patients required an arthrodesis of the ankle or subtalar joints.9

 

Certain subtalar dislocations are clearly associated with a worse prognosis. Lancaster et al.,109 in a review of the literature, noted that associated injuries and complications were associated with a worse result. In particular, soft tissue injury, extra-articular fracture, intra-articular fracture, and osteonecrosis were associated with a worse outcome.109 Open fractures are undoubtedly associated with the poorest results. Goldner et al.62 reviewed 15 patients at a mean of 18 years following an open subtalar dislocation. Associated injuries were noted to the tibial nerve in 10 patients, to the posterior tibial tendon in five, and to the posterior tibial artery in five. Seven patients ultimately required arthrodesis due to osteonecrosis or posttraumatic arthritis. They concluded that only fair functional and poor anatomic results can be expected following these severe injuries.62

 

The mechanism of injury is an important factor in predicting long-term outcome. Inversion dislocations resulting from a low-energy mechanism, such as the “basketball foot,” rarely result in long-term morbidity. Violent mechanisms such as a fall from a height or a motor vehicle collision are much more likely to cause long-term problems. Lateral subtalar dislocations may have a worse outcome compared to medial dislocations, but it is likely that the energy of the mechanism is more important than the direction.35 Associated fractures and articular cartilage damage may also be more common with lateral dislocations.

 

Osteonecrosis of the talus may develop following peritalar dislocations. Overall, osteonecrosis is uncommon and generally only noted with high-energy and open injuries. Theoretically, the talus is not displaced from the ankle mortise and, therefore, at least some of the blood supply should be preserved. However, Goldner et al.62 noted osteonecrosis in 5 of 15 patients with type III open subtalar dislocations, and Bibbo et al.9 noted osteonecrosis in three patients.

 

Persistent instability is fortunately uncommon.89,112 The subtalar and talonavicular joints have a substantial degree of intrinsic stability such that early mobilization can usually be undertaken safely and effectively. However, repeat subluxation has been noted when immobilization was discontinued early217 and in patients with generalized joint laxity.89 Subluxation which occurs early may be treated with repeat closed reduction with good results.80

 

Posttraumatic arthritis is common after a peritalar dislocation. The causes of arthritis include associated fractures, cartilage damage, and potentially unrecognized instability. Arthritis can be noted in the ankle or the midfoot, but is most common in the subtalar joint itself. Reports on the incidence of subtalar arthritis range from as low as 25% to as high as 89%.9,35,80,127,217 Although the subtalar changes that are seen radiographically are not always symptomatic, progression to severe and painful arthritis can only be treated with an arthrodesis.

 
Total Dislocation of the Talus
 
Mechanism of Injury
 

Total dislocation of the talus is a rare injury, resulting from an extension of the forces causing a subtalar dislocation. An extension of the supination force causing medial subtalar dislocation will result in a total lateral talar dislocation, and an extension of the pronation force causing a lateral subtalar dislocation will result in a total medial talar dislocation (Fig. 60-39).114 The injury is usually associated with some degree of associated fracture in the hindfoot but has been reported without fracture in a rare case of posterior dislocation.164

 
Figure 60-39
More extreme application of the same forces that produced subtalar dislocation can result in total talar dislocation.
 
Supination produces medial subtalar dislocation (A) followed by subluxation and finally complete lateral dislocation of the talus (B). Pronation initially produces lateral subtalar dislocation (C), followed by talar subluxation, and eventually total medial dislocation of the talus (D).
 
(Adapted from Leitner B. The mechanism of total dislocation of the talus. J Bone Joint Surg. 1955;37-A:93.)
Supination produces medial subtalar dislocation (A) followed by subluxation and finally complete lateral dislocation of the talus (B). Pronation initially produces lateral subtalar dislocation (C), followed by talar subluxation, and eventually total medial dislocation of the talus (D).
View Original | Slide (.ppt)
Figure 60-39
More extreme application of the same forces that produced subtalar dislocation can result in total talar dislocation.
Supination produces medial subtalar dislocation (A) followed by subluxation and finally complete lateral dislocation of the talus (B). Pronation initially produces lateral subtalar dislocation (C), followed by talar subluxation, and eventually total medial dislocation of the talus (D).
(Adapted from Leitner B. The mechanism of total dislocation of the talus. J Bone Joint Surg. 1955;37-A:93.)
Supination produces medial subtalar dislocation (A) followed by subluxation and finally complete lateral dislocation of the talus (B). Pronation initially produces lateral subtalar dislocation (C), followed by talar subluxation, and eventually total medial dislocation of the talus (D).
View Original | Slide (.ppt)
X
 
Treatment and Prognosis
 

As with most severe talus fractures and dislocations, complete dislocation of the talus is a devastating injury. Results are complicated by infection, osteonecrosis, and posttraumatic arthritis. Most of the injuries are open. Detenbeck and Kelly38 reported a series of nine cases of complete dislocation of the talus. Eight of the nine eventually required talectomy for control of persistent infection.38

 

Initial treatment is directed to the soft tissues. An early and thorough debridement of contaminated and nonviable tissue is performed, as well as an urgent reduction of the talus to reduce skin tension. In the limited number of available series, most authors have recommended reduction and preservation of the native talus, with arthrodesis and talectomy reserved for treatment of complications.81,101,120,133,145,169,179 Based upon their results, Detenbeck and Kelly38 recommended excision of the talus and primary tibiocalcaneal arthrodesis. However, Taymaz and Gunal195 report a case treated simply with closed reduction and 6 weeks of immobilization in which the patient had an essentially normal ankle at 9 years of follow-up, demonstrating that the outcome is not universally poor.

 

In general, an open reduction of the completely dislocated talus is required. Aids to reduction include a calcaneal traction pin or distractor. An anteromedial or anterolateral arthrotomy can be used. Blocks to reduction include the extrinsic tendons, associated fracture fragments, and capsular soft tissues.126 The reduction is frequently unstable, requiring transfixion of the subtalar or talonavicular joints. Immobilization should be continued until soft tissue healing has achieved stability, which is usually at least 6 weeks. Osteonecrosis can be anticipated such that early treatment with a patellar tendon bearing orthosis may be considered. Because of the anticipated development of complications, including osteonecrosis and arthritis, patients should be counseled that reconstructive surgery is likely to be required in the future in the form of arthrodesis of involved and symptomatic joints.

Controversies and Future Directions Related to Fractures and Dislocations of the Talus

Injuries to the talus and its surrounding joints are challenging and relatively uncommon injuries. Although a substantial body of literature exists regarding treatment options, results, and outcomes, there are no randomized trials to guide treatment. 
Several controversies emerge from a review of the literature. Surgical timing is frequently discussed in the literature. Since the classic articles of Hawkins,76 Canale and Kelly,20 Penny and Davis,158 and others,1,2,15,20,42,94,118,124,157,161 emergent treatment of talar neck fractures has been recommended. The rationale for emergent treatment includes a reduction of osteonecrosis rates related to earlier reduction and decreasing secondary soft tissue injury. However, other authors have compared the results of early and delayed treatment and found no difference. Lindvall et al.116 compared the results of surgery within 6 hours to delayed surgery in a group of 26 isolated fractures of the talar neck and body, and found no difference in the rates of union, osteonecrosis, or arthritis and no difference in functional outcome. Other authors have had similar findings.173,204 Although the power of these retrospective reviews to detect differences in outcome related to surgical timing is very limited by small numbers, differences in treatment techniques, and variables in fracture and patient characteristics, the current literature does not imply a benefit to immediate reduction compared to a delay of 24 hours or less.156 Very large series of talar neck fractures would be required to determine the benefit (if one exists) of immediate versus urgent or delayed surgical treatment of talar neck fractures. 
Other areas of controversy include the use of small plates as compared to screws for fixation and the use of biologically active bone substitutes for grafting. These controversies are related to the availability of new and better technologies. For example, the use of small plates for stabilization has been a comparatively recent phenomenon but seems to be evolving.55,204 Promising future considerations for talus fracture surgery include improved technology in bone graft substitutes to potentially improve union rates and perhaps eventually enhance revascularization. The use of growth factors to enhance the vascular supply, in particular, may be a promising area for further investigation. 
An additional area of controversy relates to the use of minimally invasive techniques to reduce and stabilize talus fractures and dislocations. The advantages of less invasive surgery include improved maintenance of the soft tissue envelope around the fracture and a more rapid, less painful recovery. However, the goals of surgery must be respected, most importantly including obtaining an anatomic reduction. With respect to the talus, the irregular shape of the bone and its articulations limits our ability to assess a reduction using closed techniques in complex fractures. However, with improvements in intraoperative imaging techniques, it may be possible to treat more talus fractures with less invasive techniques in the future. 

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