Lateral Malleolar Fractures.: The stability of an isolated lateral malleolar fracture depends on the location of the fracture in relation to the level of the tibiotalar joint, which defines the distal portion of the syndesmotic ligament and the stability it provides to the ankle joint. The Danis-Weber classification (see Fig. 58-8) is useful and predictive of outcome in these types of unimalleolar fractures.³³ This classification groups fractures into three groups (A, B, and C), each of which has three subgroups. Lateral malleolar fractures below the tibiotalar joint (Danis-Weber type A) rarely disrupt other bony or ligamentous structures, and in the absence of injury to the medial structures such fractures are unlikely to affect the dynamic congruity of the ankle joint.³⁸ The management of uncomplicated lateral malleolar fractures involves casting for 6 to 8 weeks, with no weightbearing for at least the first 3 weeks, and ongoing follow-up to ensure proper union. Concomitant tenderness over the deltoid ligament may suggest a biomechanical disruption of both malleoli, an associated fracture of the medial malleolus, or an associated fracture of the posterior malleolus and warrants orthopedic consultation in the ED, especially if the medial clear space on the mortise view is widened (see Fig. 58-6).³⁸ CT imaging can be useful in such situations as it may identify occult medial or posterior malleolar fractures.

Fibular fractures proximal to the tibiotalar joint line (a Danis-Weber type C injury; see Fig. 58-8) frequently, but not always, disrupt the distal tibiotalar syndesmosis and the medial structures and commonly require orthopedic consultation in the ED and operative intervention. Treatment of an isolated fracture at the level of the tibiotalar joint (a Danis-Weber type B injury; see Fig. 58-8) is controversial because 50% of these injuries are accompanied by an injury to the distal tibiofibular syndesmosis that may require operative intervention.⁴⁰ Distal tibiofibular space measurements on plain radiography have a sensitivity of only 31% and a specificity of 83%, compared with CT scan, in detecting tibiofibular syndesmosis injuries.⁴¹ Tenderness on palpation of the syndesmotic ligament or a widening of the medial joint space on the mortise view adds further support to the need for emergency consultation.

Medial Malleolar Fractures.: Medial malleolar fractures are usually the result of eversion or external rotation. These two forces exert tension on the deltoid ligament, causing an avulsion of the tip of the medial malleolus or a rupture of the deltoid ligament. Although they can occur in isolation, medial malleolar fractures are commonly associated with lateral or posterior malleolar disruption. Because of this, the identification of a medial malleolar fracture warrants a careful examination of the entire length of the fibula for tenderness, the presence of which warrants radiographic evaluation to rule out a proximal fibular fracture (Fig. 58-9).

An isolated nondisplaced medial malleolar fracture can be treated with casting for 6 to 8 weeks, with no weightbearing for at least the first 3 weeks and close orthopedic follow-up. Any displacement or concomitant disruption of the lateral components of the ankle warrants orthopedic consultation in the ED for consideration of operative management.³⁸

Posterior Malleolar Fractures.: Isolated fractures of the posterior malleolus are rare and imply an avulsion of the posterior tibiofibular ligament. These injuries can be associated with proximal fibular fractures and medial and lateral collateral ligament sprains. Treatment usually consists of casting for 6 weeks, provided that no associated injury or ankle instability is present.⁴² Fractures involving more than 25% of the tibial surface usually require open reduction and internal fixation.³⁸

Pathophysiology.: Most ankle sprains occur from extreme inversion and plantar flexion causing symptoms on the lateral aspect of the ankle. Usually the anterior talofibular ligament is injured first, followed by the calcaneofibular ligament if the deforming forces are sufficiently strong (see Fig. 58-1). Approximately two thirds of ankle sprains are isolated anterior talofibular ligament injuries, whereas 20% involve both anterior talofibular and calcaneofibular ligament injuries. In addition, the lateral talocalcaneal ligament may be stressed with an inversion injury, leading to avulsion fractures at either end of the attachment sites.⁶¹ Isolated calcaneofibular or posterior talofibular ligament injuries are rare.

Isolated injury of the deltoid ligament occurs in less than 5% of ankle sprains. Rupture of this ligament occurs most commonly in conjunction with lateral malleolar fractures, especially when an external rotational force is involved.

Injuries of the distal tibiofibular syndesmotic ligaments are uncommon in the general population but may represent 10 to 20% of injuries in competitive athletes.⁶² Dorsiflexion and external rotation forces are usually responsible for this injury, the presence of which may significantly prolong the recovery time from lateral collateral ligament sprains.⁶²

Ligamentous injuries are classified into three grades based on functional and presumed pathologic findings. A grade I injury involves ligamentous stretching without grossly evident tearing or joint instability. A grade II injury involves a partial tear of the ligament with moderate joint instability, often accompanied by significant localized swelling and pain. A grade III injury involves a complete tear of the ligament with marked joint instability, severe edema, and ecchymosis. This classification system, although commonly used, fails to characterize ankle injuries involving two or more ligaments, and it does not consider nonligamentous injuries. Although more comprehensive classification systems have been proposed,⁶¹ there is a strong association with increased gradation of ankle sprain and long-term risk of chronic instability, early osteoarthritis, chronic pain, and permanent disability.^63,64

Clinical Features.: Although desirable, an accurate history of ankle position and injury mechanism is often unavailable. Inversion followed by external rotation of the ankle suggests the potential for deltoid or syndesmotic injury. Forced dorsiflexion with snapping may indicate peroneal tendon displacement. Previous injuries to the same ankle or symptoms of recurrent ankle instability or pain suggest the presence of a subacute or chronic pathologic process.

On physical examination, the presence of edema, ecchymosis, and point tenderness over the medial or lateral collateral ligaments or the syndesmotic ligaments suggests a ligamentous injury. Inability to bear weight in the absence of a fracture suggests the presence of a grade II or III ankle sprain.⁶⁵ With inversion injuries, point tenderness may also be present along the distal fibula, the lateral aspect of the talus, the lateral aspect or anterior process of the calcaneus, or the base of the fifth metatarsal. Deltoid ligament tenderness necessitates palpation of the full length of the fibula to rule out a proximal fibular fracture (a type C Danis-Weber or Maisonneuve fracture; see Figs. 58-8 and 58-9) and a low threshold for imaging the entire tibia and fibula should exist. The fibular compression test, also known as the squeeze test, reveals fibular and syndesmotic injuries.⁶² To perform this test, the examiner places the fingers over the fibula and the thumb over the tibia at midcalf and squeezes the two bones. Pain anywhere along the length of the fibula suggests a fibular fracture or an interosseous membrane or syndesmotic ligament disruption at that location.⁶² Finally, the Achilles tendon should be assessed.

Stress testing is the application of a deforming force to assess joint motion beyond the physiologic range, the presence of which suggests ligament disruption or mechanical instability. Although rarely required, stress testing is safe to perform and can be helpful for acute and severe ankle injury in which rupture of two or more ligaments is suspected, a fracture suspected to be isolated in which the presence of an additional ligament rupture would influence management, the possibility of a concomitant syndesmotic injury, follow-up evaluation of an acute ankle injury after pain and swelling have subsided, and a chronically symptomatic ankle. With the exception of these scenarios, stress testing is not indicated because it is painful and does not alter management. The normal ranges for stress tests are controversial, so the uninjured side should be examined for comparison.

Common ankle stress tests include the anterior drawer test, the inversion stress test, and the external rotation test. The anterior drawer test primarily assesses the integrity of the anterior talofibular ligament. For this test to be performed, the patient is seated with the knee in 90 degrees of flexion and the ankle in a neutral position or 10 degrees of plantar flexion. The examiner then pulls on the heel with one hand and pushes the leg posteriorly with the other. Anterior displacement of the talus, the perception of a “clunk,” and the induction of a sulcus anteromedially over the joint indicate partial or complete tear of the anterior talofibular ligament.

The inversion stress test, or talar tilt test, evaluates both the anterior talofibular ligament and the calcaneofibular ligament. It is performed by inverting the heel with the knee in 90 degrees of flexion and the ankle in neutral position. Palpation of the head of the talus laterally or a finding of increased laxity compared with the uninjured side suggests partial or complete tear of these ligaments.

The external rotation stress test is indicated when injury to the distal tibiofibular syndesmotic ligaments is suspected. It is performed by externally rotating the foot with the knee in 90 degrees flexion and the ankle in a neutral position. Pain at the syndesmosis or the sensation of lateral talar motion suggests partial or complete tear of the ligaments.

Diagnostic Strategies: Radiology.: Standard ankle radiographic views are useful to exclude fractures and to detect instability by the measurement of joint spaces (see earlier discussion and Fig. 58-6).⁸ Presence of avulsion fractures, which can be located at the bases of the malleoli, the lateral process of the talus, the lateral aspect of the calcaneus, the posterior malleolus, the lateral aspect of the distal tibia, or the base of the fifth metatarsal, constitute an important clue to the location of ligamentous injuries.

In addition to the standard mortise measurements previously discussed, two measurements on the anteroposterior radiograph further evaluate the distal tibiofibular syndesmosis (see Fig. 58-6).⁸ At the distal overlap between the fibula and the tibia, the distance between the posterior edge of the lateral tibial groove and the medial fibular cortex (syndesmosis A) should not exceed 5 mm.⁸ Furthermore, the amount of tibiofibular bony overlap (syndesmosis B) should be at least 10 mm.⁸ Measurements outside of these values suggest a syndesmotic diastasis. Stress radiographs, accomplished by taking radiographs during stress testing of the ankle, generally do not influence the emergency management of ankle sprains and are not recommended.⁶⁶

Many injuries can masquerade as ankle sprains.⁵⁸ Box 58-2 lists conditions to be considered in the differential diagnosis; Figure 58-12 shows locations of common fractures in or near the ankle that can be misdiagnosed as an ankle sprain.

Management.: Most ligament sprains, regardless of severity, heal well and result in a satisfactory outcome. To date, compelling evidence for a significant difference in outcomes between surgical and functional (nonsurgical) treatment is lacking. Limited data suggest that recovery times may be longer and complications more frequent with surgical treatment.⁶⁷ Most patients with acute sprains of the ankle should start with functional treatment.⁶⁸ For the minority who fail to respond, delayed operative repair of ruptured ligaments, sometimes years after the injury, has been shown to yield results equivalent to those with primary repair.^68,69

Functional treatment, which is defined as a form of therapy in which the ankle is not fully immobilized, allowing either complete or partial joint function, starts in the ED with RICE therapy (rest, ice, compression, and elevation); however, significant variability exists in how this combination is applied, and the optimal methods remain unclear.60,61,70 The evidence to date suggests that lace-up ankle support is more effective in short-term edema reduction than semirigid ankle support, elastic bandaging, and taping. Elastic bandaging causes fewer complications than taping but appears to correlate with slower return to work and sports.⁶⁰ One study suggests that compared with elastic bandaging, ankle bracing with a lace-up brace such as the Air-Stirrup Ankle Brace (Aircast, DJO Inc., Vista, Calif.) leads to improved functioning at both 10 days and 1 month.⁷¹

For grade I or II injuries, short-term protection with a tensor bandage, taping, a laced-up support, or a commercial walking boot or brace, with the optional use of crutches for a few days, is appropriate.68,70 For patients with first-time ankle sprains, treatment with a lace-up stirrup brace combined with elastic wrapping results in an earlier return to function compared with use of a brace alone, elastic wrap alone, or a walking cast.⁷² For severe grade II or grade III injuries, there is currently equipoise regarding the merit of immobilization compared with functional rehabilitation, with little high-quality evidence to guide therapy.^73,74 A recent study supports a 10-day period of immobilization with a below-knee cast or Aircast ankle brace to speed recovery from ankle sprains, with immobilization leading to reduced symptoms and faster recovery compared with tubular compression bandages.⁷⁵ However, a weakness in this study was the lack of a control group incorporating an active ankle physiotherapy program, known to be important for improved recovery. An accelerated functional rehabilitation program carried out over the first week of injury has also recently been shown to improve function in grade I and II ankle sprains in the short term.⁷⁶

Because there is little evidence for a more favorable outcome with complete immobilization over functional treatment incorporating a removable brace, the use of a lace-up support or air cast that permits some ankle motion is generally preferable.68,74,77 Such patients should also use crutches to avoid weightbearing until they can stand and walk a few steps on the injured ankle without pain. How long crutches will be required varies significantly, ranging from a few days to 2 or 3 weeks. Follow-up care with the patient’s primary physician within the first 2 weeks is appropriate for minor sprains, whereas orthopedic or sports medicine referral on an outpatient basis is prudent for severe sprains.

Analgesics are often necessary for pain management in ankle injuries, and studies suggest that nonsteroidal anti-inflammatory agents, acetaminophen, or oral opioids for severe cases are efficacious.78–80 Topical diclofenac gel also has been shown to have efficacy in pain reduction and allowing early mobilization.^67,81,82

After the acute management phase, the next two phases of functional treatment involve appropriate early rehabilitation and occur outside the ED.⁸³ Phase two, which begins after swelling has subsided and the patient is able to bear weight easily, involves strengthening the peroneal and dorsiflexor muscles by isometric, concentric, and eccentric exercises. The final phase begins when full range of motion has been reestablished and the patient can exercise painlessly. This starts with exercises to rebuild motor coordination and proprioception, recondition the muscles, and increase endurance. The patient uses an ankle tilt board or disk to develop coordination and performs increasingly demanding functional activities (e.g., brisk walking, running, and figure-of-eight running to hopping, jumping, and cutting) to build up the muscle groups.^83,84 With severe sprains the patient may benefit from the use of air casts, braces, or taping during the latter two phases of functional treatment and in the initial period of return to sports.⁸³ The entire treatment program usually lasts 4 to 6 weeks, depending on the injury’s severity.^61,70,85

Disposition.: Rarely, orthopedic consultation in the ED is indicated for an acute ligament sprain. Primary surgical repair of acute ligament rupture is controversial, and possible indications include sprains with displaced osteochondral lesions, complete tears of both the anterior talofibular and calcaneofibular ligaments in a young athlete, a ligament sprain associated with a fracture causing instability (e.g., a deltoid ligament rupture with a lateral malleolar fracture), and an acute severe sprain in a patient with a history of recurrent and severe sprains.⁶¹ Failure of nonoperative treatment also constitutes an indication for surgical repair; however, an orthopedic referral on an outpatient basis is adequate ED management.⁶⁹

Small avulsion fractures of the fibula with minimal or no displacement can be treated in the same manner as an ankle sprain. If the avulsed fragment is larger than 3 mm or significantly displaced, splinting and referral for orthopedic follow-up on an outpatient basis are justified.

Despite appropriate treatment, chronic problems develop in 10 to 30% of patients with ankle sprains.⁷⁰ These include functional instability, mechanical instability, chronic pain, stiffness, and recurrent swelling and occur more often in grade III ankle sprains.

Functional instability refers to the patient’s subjective sensation that the ankle gives way during activity. Although this may be a minor nuisance for some people, it can be devastating and debilitating for persons whose activities demand a high degree of ankle stability. Mechanical instability results from ligamentous laxity, which allows ankle joint movements beyond the physiologic range. In contrast to functional instability, mechanical instability can often be demonstrated clinically by the anterior drawer or talar tilt test and stress radiographs.⁶¹

Soft tissue abnormalities that cause chronic pain include synovial impingement, peroneal tendon subluxation or dislocation, intra-articular loose bodies, anterior tibiofibular syndesmotic ligament injuries, and degenerative arthritis. Bone-related causes of chronic pain include osteochondral lesions, fractures of the anterior process of the calcaneus, fractures of the lateral process of the talus, and anterior and posterior impingement.58,86

Patients with any of these chronic conditions should be referred for orthopedic follow-up care because they may require further imaging or arthroscopy for diagnosis or definitive treatment.

Achilles Tendon Rupture.: Achilles tendon rupture is most common in middle-aged men, and its causes are multifactorial. This condition is easily misdiagnosed, leading to a delay in therapy, a worse prognosis, and increased morbidity, including chronic weakness and loss of function. In the great majority of cases, a complete transection of the tendon is present; however, partial tears of the Achilles tendon can occur and may be more prone to misdiagnosis.

Achilles tendon rupture results from direct trauma or indirectly transmitted forces, including sudden unexpected dorsiflexion, forced dorsiflexion of a plantar-flexed foot, and strong push-off of the foot with simultaneous knee extension and calf contraction (as in a runner accelerating from the starting position). Factors predisposing to Achilles tendon rupture include preexisting disease such as rheumatoid arthritis, systemic lupus erythematosus, gout, hyperparathyroidism, or chronic renal failure, steroid use or injection, fluoroquinolone antibiotic therapy, and previous Achilles tendon rupture.⁸⁷

The diagnosis of Achilles tendon rupture is primarily clinical. Patients usually describe a sudden onset of pain at the back of the ankle associated with an audible “pop” or “snap.” Although the pain can resolve rapidly, weakness in plantar flexion persists. On examination, a visible and palpable tendon defect may be noted 2 to 6 cm proximal to the calcaneal insertion in acute presentations but will be less apparent in delayed presentations because of hematoma or edema. Even in cases of complete Achilles tendon rupture, weak plantar flexion may still be possible because of the actions of the tibialis posterior, toe flexors, and peroneal muscles. This retained ability for plantar flexion often leads to the misdiagnosis of complete ruptures as ankle strains or partial tears in as many as 25% of cases.⁸⁸ The classic maneuver to assess the integrity of the Achilles tendon is the Thompson test.⁸⁹ This is performed with the patient prone and the knee flexed at 90 degrees or the feet hanging over the end of the stretcher. Alternatively, the patient kneels on a chair with both knees flexed at 90 degrees and the feet hanging over the edge. Squeezing the calf muscles in these two positions should cause passive plantar flexion of the foot. Absence of this motion, or a markedly weakened response compared with the uninjured side, suggests complete rupture. Another recently described diagnostic test, the reverse Silfverskiöld test, compares dorsiflexion of the injured ankle with that in the uninjured ankle while the patient is in the supine position. Achilles tendon rupture results in a notably increased degree of dorsiflexion compared with the uninjured side.⁹⁰

Lateral radiographic views of the ankle may suggest rupture by showing opacification of the fatty tissue–filled space anterior to the Achilles tendon (Kager’s triangle) or an irregular contour and thickening of the tendon.⁸⁸ Ultrasonography or MRI can demonstrate partial or complete tendon ruptures, but these studies are indicated only in cases in which diagnostic uncertainty exists.⁸⁸

A lack of consensus exists regarding the choice between operative and nonoperative management in the treatment of Achilles tendon rupture.91–93 Surgical repair is routinely performed in active individuals owing to its lower incidence of rerupture. However, surgery carries higher rates of other complications, such as superficial or deep wound infections, in comparison with nonoperative management.^91,94 In both types of management, early mobilization improves functional recovery without increasing rerupture rates.^91,93 Minimally invasive surgery combined with early rehabilitation with postoperative functional bracing may further improve outcome.^95,96 Achilles tendon rerupture after initial nonoperative treatment usually necessitates surgical repair, with substandard results compared with primary repair.⁹⁷ ED orthopedic referral of patients with Achilles tendon rupture is necessary to determine the appropriate management.

Peroneal Tendon Dislocation or Tear.: The peroneal muscles are the primary evertors and pronators of the foot and also participate in plantar flexion. The peroneus longus and brevis tendons use the posterior peroneal sulcus (the fibular groove), located behind and underneath the lateral malleolus, as a pulley for their midfoot insertions. The peroneus brevis tendon inserts onto the tuberosity of the fifth metatarsal, and the peroneus longus tendon courses beneath the cuboid to insert onto the medial cuneiform and base of the first metatarsal. The superior peroneal retinaculum (Fig. 58-13), a fibrous structure running from the distal fibula to the posterolateral aspect of the calcaneus, maintains the peroneal tendons against the fibular groove.

Anterior subluxation or dislocation of the peroneal tendons occurs as a result of a tear of the superior peroneal retinaculum attachment from the fibula.98,99 This infrequent injury is commonly misdiagnosed as an ankle sprain and can occur in isolation or concomitant with other sprains or fractures. The mechanism of injury usually is forced dorsiflexion with reflex contraction of the peroneal muscles, resulting in avulsion of the retinaculum and anterior displacement of the peroneal tendons.⁹⁸

Patients with a peroneal tendon dislocation complain of sudden pain and a snapping sensation over the posterolateral ankle associated with weakness of eversion. Tenderness and swelling over the lateral retromalleolar area (a location not typically involved in ankle sprains) are characteristic. When accurate examination is not precluded by swelling, the dislocated tendons also may be palpable near the inferior tip of the lateral malleolus. Inability to actively evert the foot when it is held in dorsiflexion or frank subluxation of the tendons with this maneuver confirms the diagnosis. Findings on plain radiography are often normal; however, 15 to 50% of patients will be found to have an associated avulsion fracture of the lateral ridge of the distal fibula. An MRI study or ultrasound can be helpful in confirming the diagnosis. All patients with a suspected or confirmed peroneal tendon dislocation should be referred for orthopedic follow-up because these injuries require surgical repair.99,100 Spontaneous healing is rare in untreated cases, and chronic ankle instability and pain are common sequelae. Peroneal tendons also can tear longitudinally; such injuries manifest either acutely or subacutely with recurrent pain and swelling during activities.^100,101

Tibialis Posterior Tendon Rupture.: The tibialis posterior is primarily responsible for plantar flexion and inversion along the subtalar joint. Its tendon uses the posteroinferior surface of the medial malleolus as a pulley and inserts onto the navicular, the medial cuneiforms, and the bases of the second through the fifth metatarsals. The peroneus brevis opposes the action of the tibialis posterior. With rupture of the tibialis posterior tendon, the peroneus brevis becomes unopposed and the medial longitudinal arch loses its muscular support, leading to valgus deformity of the hindfoot and a unilateral flatfoot.¹⁰²

The mechanism of traumatic tibialis posterior rupture involves forced eversion.¹⁰² In addition to a unilateral flatfoot, pain and swelling on the medial aspect of the ankle are seen. Tenderness is present over the navicular, and the patient cannot perform a toe raise on the affected side. In addition, the patient with a tibialis posterior tendon rupture is unable to invert the foot when it is in plantar flexion and eversion. With a unilateral flatfoot, an observer standing behind the patient can see “more toes” on the lateral aspect of the affected side—a classic sign.¹⁰² Plain radiography can exclude other bone abnormalities. Ultrasonography and MRI are useful imaging modalities to diagnose this condition.¹⁰² Orthopedic consultation is indicated for tibialis posterior tendon ruptures, because surgical repair often is necessary.

Other Tendon Injuries.: The tibialis anterior is the primary dorsiflexor of the foot. Its tendon courses under the superior extensor retinaculum and inserts onto the navicular, the medial cuneiform, and the base of the first metatarsal. Tenosynovitis of the tibialis anterior tendon is associated with overuse and characterized by swelling, tenderness, and crepitus along the tendon. Treatment involves RICE therapy, analgesia, and close follow-up. Rupture of the tibialis anterior is rare and often is misdiagnosed as lumbosacral radiculopathy or peroneal nerve palsy because of the footdrop it produces. This condition requires orthopedic consultation in the ED because surgical repair is usually necessary.

The flexor hallucis longus is responsible for flexion of the great toe and participates in plantar flexion of the foot. Its tendon courses behind the medial malleolus through a fibro-osseous canal and inserts onto the distal phalanx of the great toe. Flexor hallucis longus tendinitis, also called dancer‘s tendinitis, most often occurs at the fibro-osseous canal.¹⁰³ On examination, tenderness and edema posterior to the medial malleolus are noted, and passive extension of the first metatarsophalangeal (MTP) joint causes significant pain when the foot is in neutral position. Initial treatment involves rest, nonsteroidal anti-inflammatory drugs, and a short course of immobilization. Orthopedic follow-up on an outpatient basis should be arranged to ensure proper resolution. Rarely, surgical intervention may be necessary.¹⁰³

Principles of Disease: Anatomy.: The word talus is related to the Latin taxillus, meaning “a small die or cube,” and dates back to the time of the Roman Empire, when soldiers made dice out of the ankle bones of horses. An appreciation of the unique anatomy of the talus is crucial to an understanding of the pathophysiology and treatment of talar fractures and dislocations. The talus is the second largest tarsal bone and has seven articulations making up 60% of its surface. It is divided into three regions: the head, which articulates with the navicular and calcaneus; the body, which articulates with the tibia, fibula, and calcaneus; and the neck, which joins the head and body and is the only portion of the talus that is predominantly extra-articular. The talus is the only bone in the lower extremity with no muscular attachments and is held in position by the malleoli and ligamentous attachments. The anterior width of the talus is greater than the posterior, causing it to be less stable and more prone to dislocation when the foot is plantar-flexed.

The blood supply to the talus is from a vascular ring formed by branches of the anterior and posterior tibial arteries and the perforating branch of the peroneal artery. Vessels enter the talus from three main sites, any or all of which can be disrupted by fractures or dislocations. Because of the tenuous nature of these vessels and the inconsistency of collateral circulation, the risk of avascular necrosis is significant with many talar fractures.

Pathophysiology.: Talar fractures are the second most common tarsal fracture after fractures of the calcaneus. They are best grouped into minor and major fractures, with minor fractures being the more common.¹²¹ Stress fractures of the talus also can occur. Minor talar fractures include avulsion fractures of the superior neck and head, and the lateral, medial, and posterior aspects of the body.¹²² These fractures often involve the same mechanism as that for ankle sprains (see Fig. 58-12 and Box 58-2): a combination of plantar flexion or dorsiflexion and an inversion force. Lateral process fractures, previously uncommon, have been described with snowboarding and can be occult on plain radiographs.¹²³ Osteochondral lesions of the talar dome also fall into the minor fracture category.

Major talar fractures usually are produced by significant forces and occur in the head, neck, or body. Talar head fractures are uncommon, making up 5 to 10% of all talar fractures. Their mechanism is a compressive force applied on a plantar-flexed foot and transmitted up through the talonavicular joint. Comminution is common, and associated navicular fractures can occur, further disrupting the talonavicular articulation.

Talar neck fractures account for 50% of major talar injuries. Their mechanism usually is an extreme dorsiflexion force, as generated in falls or MVCs. Associated fractures are common; the most common is an oblique or vertical fracture of the medial malleolus, which is seen in up to one fourth of cases. Other associated injuries include calcaneal fractures and vertebral compression fractures.

Hawkins classified talar neck fractures into three categories (Fig. 58-16): Type 1 fractures are nondisplaced; type 2 fractures show subtalar subluxation; and type 3 fractures, 50% of which are open, involve a dislocation of the talar body from the ankle and subtalar joint. A fourth type that has been added to this classification involves the additional distraction of the talonavicular joint. This classification is important descriptively and because the type of fracture influences both treatment and outcome. Long-term complications, including avascular necrosis and arthritis, are common with talar neck fractures and more likely with increasing displacement.¹²⁴

Talar body fractures include many of the minor talar fractures previously listed.¹²⁵ Major talar body fractures are uncommon and usually result from falls with axial compression of the talus between the tibial plafond and the calcaneus.

Clinical Features.: Talar fractures range from obvious open fractures to subtle fractures requiring special imaging techniques to diagnose. Typically, a history of a twisting injury, fall, or high-energy impact can be elicited. Dorsal swelling and tenderness over the talus are characteristic findings. Although ankle motion may be preserved, inversion and eversion of the hindfoot often are painful.

Diagnostic Strategies: Radiology.: With minor talar fractures, radiographs can be misinterpreted as normal in appearance. Even when supplemental views are obtained, CT or MRI may be required for visualization. Standard foot and ankle radiographic views usually demonstrate major talar fractures (Figs. 58-17 and 58-18), with the anterior and oblique projections showing talar alignment within the mortise and the lateral projection showing the talar neck and alignment of the posterior aspect of the subtalar joint. Normal variants, such as an os trigonum or os supratalare (see Fig. 58-15), are occasionally encountered and should be differentiated from fractures. Specialized imaging by CT or MRI is often required for complete assessment of talar fractures.

Management.: Major talar fractures require precise reduction because more weight per unit area is borne by the superior surface of the talus than by any other bone. Most talar fractures involve multiple articular surfaces, and adequate repair often necessitates open reduction and internal fixation. Many minor talar fractures heal with casting, and the initial treatment should be with a non–weight-bearing below-knee cast or posterior plaster slab. Fragments larger than 5 mm in diameter may require excision. Other minor fractures, such as displaced lateral process fractures, require operative fixation because of their articular involvement.

The treatment of major talar fractures is controversial. Any significantly displaced fracture, particularly if associated with neurovascular or cutaneous compromise, requires an early attempt at closed reduction in the ED. Even if nonoperative reduction is impossible, as is common in type 3 and type 4 neck fractures with an intact medial malleolus, alignment often can be improved. With neurovascular or cutaneous compromise, reduction should not be delayed by waiting for radiography or consultation. After appropriate procedural sedation and analgesia, reduction is performed by grasping the hindfoot and midfoot and applying longitudinal traction with plantar flexion. This is followed by realignment of the foot as reduction is achieved. Reevaluation of the neurovascular status, posterior slab immobilization, and postreduction radiographs should then follow.

Displaced talar head fractures or those involving more than 50% of the articular surface usually require open reduction and internal fixation, followed by non–weight-bearing casting. Smaller fragments may require excision. Type 1 fractures of the talar neck usually are treated with non–weight-bearing casting for 8 to 12 weeks. Most type 2 and all type 3 and type 4 fractures require open reduction and internal fixation. The management of talar body fractures varies with anatomic location.

Disposition.: All patients with talar fractures require orthopedic consultation in the ED or referral for early orthopedic follow-up on an outpatient basis. Most minor talar fractures are suitable for outpatient follow-up and heal well, although some result in post-traumatic arthritis. Major talar fractures have a high incidence of complications, the most significant of which is avascular necrosis.¹²⁶ Outcome depends on the degree of anatomic reduction attained and preservation of the vascular supply. The risk of avascular necrosis increases with delay to reduction and with increasing talar displacement, ranging from 10% for type 1 neck fractures to 70% or more for type 3 neck fractures. Major fractures of the talar body are also prone to avascular necrosis, the risk of which doubles if an associated dislocation is present. Other potential complications include skin infection, skin necrosis, post-traumatic arthritis, malunion, delayed union, nonunion, and predisposition to peroneal tendon dislocation. The incidence of each complication varies with the type of fracture and the aggressiveness of ED and operative management.

Principles of Disease: Pathophysiology.: Subtalar dislocation, also called peritalar dislocation, is the simultaneous disruption of both the talocalcaneal and talonavicular joints without disruption of the tibiotalar joint (Fig. 58-20). This occurs when the talonavicular and talocalcaneal ligaments rupture while the stronger calcaneonavicular ligament remains intact. Subtalar dislocations are rare and are classified by the direction the foot takes in relation to the talus.¹³⁴ Anterior and posterior dislocations occasionally occur; however, most subtalar dislocations are either medial or lateral, with medial dislocations accounting for a majority of cases. Dislocation of the calcaneus is an exceptionally rare event that is distinct from subtalar dislocation and involves disruption of the talocalcaneal and calcaneocuboid articulations.

Subtalar dislocations are caused by severe torsional forces such as those generated in MVCs or falls. Medial dislocations result from inversion and plantar flexion, whereas lateral dislocations arise from the combination of eversion and plantar flexion. Ten percent of subtalar dislocations are open, and associated fractures are present in one half of the cases, particularly those with lateral dislocations.

Clinical Features.: Obvious deformity typically is present, often with tension of the skin on the side opposite the direction of dislocation. Neurovascular status should be carefully assessed, although it is rarely compromised. Swelling can mask the extent of the injury, thus diagnosis can be delayed or missed if only ankle radiographs are obtained.

Diagnostic Strategies: Radiology.: Although standard foot radiographic views are diagnostic, properly positioning the patient for these may be difficult. Inadequate films can delay diagnosis and treatment. The single most helpful radiograph is an anteroposterior view of the foot, which will demonstrate the talonavicular dislocation.

Management.: Subtalar dislocations require expeditious reduction.¹³⁵ More than 80% of closed subtalar dislocations can be treated with closed reduction, either with procedural sedation and analgesia in the ED or with general anesthesia. Closed reduction is performed by flexing the knee and applying longitudinal traction to the foot with initial accentuation, followed by reversal of the deformity (with use of eversion for medial dislocations and inversion for lateral dislocations). Sometimes direct pressure over the head of the talus aids in reduction. Closed reduction may be impossible because of buttonholing of the talus through the extensor retinaculum, entrapment in the peroneal tendons, or associated fractures. After reduction, immobilization in a below-knee cast for 4 to 6 weeks is indicated.

Disposition.: Urgent ED orthopedic consultation is indicated for subtalar dislocations. Although serious complications are uncommon in cases of closed subtalar dislocation, most patients have long-term limitation of subtalar motion, a sequela that can affect gait. Avascular necrosis is uncommon.

Principles of Disease: Anatomy.: The calcaneus is the largest bone in the foot and the most commonly fractured tarsal bone.¹³⁷ It articulates with the talus superiorly (forming the subtalar joint) and with the cuboid anterolaterally.

Pathophysiology.: Falls with direct axial compression cause most calcaneal fractures. Because of this high-energy mechanism, associated injuries are common: 7% of calcaneal fractures are bilateral, 25% are associated with other lower extremity injuries, and 10% are associated with spinal injuries, typically vertebral compression fractures.

Numerous classification schemes have been developed for calcaneal fractures. Perhaps the most intuitive is simple categorization of the fracture as either extra-articular or intra-articular. Extra-articular fractures usually involve the addition of a rotatory mechanism and include fractures of the sustentaculum tali and the calcaneal tuberosity and oblique fractures of the calcaneal body. Avulsion fractures of the anterior process by the bifurcate ligament (which joins the calcaneus, navicular, and cuboid) also are included in this category. Isolated calcaneal tuberosity fractures are rare but may require more expeditious treatment when displaced owing to compromise of the skin overlying the Achilles tendon.¹³⁸ Up to 75% of calcaneal fractures are intra-articular, ranging in severity from nondisplaced single fractures to severely crushed, comminuted fractures. Because of the cancellous nature of the calcaneus, fractures are frequently comminuted. Calcaneal stress fractures may also occur.

Clinical Features.: The typical history is one of a fall resulting in a direct impact on the heel or heels. Physical examination reveals pain, swelling, and tenderness over the affected heel, and weightbearing on the hindfoot is usually impossible. In cases of significant fracture, the heel may be deformed when viewed from behind, appearing short, wide, and tilted. Ecchymoses may extend over the entire sole, a finding not seen in isolated malleolar fractures. The presence of compartment syndrome or associated injuries such as vertebral compression fractures should be considered.

Diagnostic Strategies: Radiology.: Standard radiographic views of the foot and ankle should be obtained. The anteroposterior view of the foot shows the calcaneocuboid joint and the anterosuperior calcaneus, whereas the lateral view shows the posterior facet and can demonstrate compression of the calcaneal body (Fig. 58-21). In addition, a Harris (axial) view, when not precluded by pain, should be obtained to image the calcaneal tuberosity, subtalar joint, and sustentaculum tali. Anterior process fractures require differentiation from a calcaneus secundarius accessory ossification center (see Fig. 58-15).¹³⁹

Two assessments are critical to the management of calcaneal fractures: whether the fracture involves the subtalar joint, and the degree of depression of the posterior facet.¹⁴⁰ Compression fractures are not always obvious, and measurement of Boehler’s angle (Fig. 58-22) can be helpful. Because Boehler’s angle may be normal even in the presence of severely comminuted calcaneal fractures, it has been considered more useful prognostically than diagnostically, although recent findings raise questions regarding the prognostic utility of this measurement as well.¹⁴¹ Boehler’s angle is measured on the lateral view as the angle between two lines, one between the posterior tuberosity and the apex of the posterior facet and the other between the apex of the posterior facet and the apex of the anterior process. Although several values for this measurement have been cited, an angle of 20 to 40 degrees defines a normal range with the best diagnostic performance.¹⁴² An angle of less than 20 degrees suggests a compression fracture. Comparison measurement of the uninjured side may be helpful in questionable cases; however, the degree of variability between feet in the same individual is poorly defined, and advanced imaging is preferable in such situations.

Imaging of the calcaneus can be difficult because of the complex three-dimensional nature of its articulations. Plain radiography can underestimate injury severity, and the CT scan has revolutionized the assessment of calcaneal fractures, with good correlation of findings with outcome.140,143 MRI is also an excellent modality for imaging the hindfoot and has a role in assessment of selected calcaneal fractures.

Management.: The management of intra-articular or displaced calcaneal fractures is controversial, with many operative and nonoperative approaches described.¹⁴⁰ Minimally invasive surgical approaches and new technologies are changing the surgical approach to these injuries.¹⁴⁴ A recently published 15-year follow-up of a randomized trial comparing operative and nonoperative management of displaced intra-articular calcaneal fractures found no differences in clinical outcomes between the treatment groups.¹⁴¹ The treatment of nondisplaced extra-articular fractures usually involves casting for 6 to 8 weeks.

Disposition.: Intra-articular or displaced calcaneal fractures require orthopedic consultation in the ED. Outpatient orthopedic follow-up care can be arranged for more innocuous injuries, provided that this approach is consistent with local practice and no associated injuries that warrant hospitalization are present. In considering outpatient follow-up, it is important to bear in mind that plain radiographs often significantly underestimate the extent and severity of calcaneal fractures. Minor extra-articular fractures usually heal uneventfully; however, with significant calcaneal fractures, complications, including compartment syndrome, are frequent. In both conservatively and surgically treated patients, the incidence of long-term pain, loss of joint mobility, and functional disability approaches 50%.¹⁴⁵

Principles of Disease: Anatomy.: The navicular has a curved shape—hence the derivation of its name from the Latin word navis, meaning “ship.” Because of the navicular’s extensive articular surface, its blood supply can enter only through a small waist of cortex, and the middle third is relatively avascular. As a result, the navicular is at particular risk for avascular necrosis after fractures, analogous to its counterpart in the wrist, the scaphoid bone.¹⁴⁹

Pathophysiology.: Navicular fractures, although relatively rare, are the most common midfoot fracture and are classified into dorsal avulsion fractures, tuberosity fractures, and body fractures. Dorsal avulsion fractures account for one half of navicular fractures and usually occur when an eversion stress causes bony avulsion from either the talonavicular capsule or the deltoid ligament. These fractures usually do not involve a significant amount of articular surface. Tuberosity fractures also occur from eversion forces, leading to an avulsion at the insertion of the posterior tibial tendon. A tuberosity fracture may be the only clue to the presence of a midtarsal joint injury. Body fractures are uncommon and result from an axial loading mechanism. They often are comminuted, intra-articular, and associated with other midtarsal pathologic conditions. Stress fractures of the navicular can also occur.

Clinical Features.: Navicular fractures cause localized tenderness over the dorsal and medial aspects of the midfoot. The navicular tuberosity may be tender and is located by first identifying the sustentaculum tali, a shelf of bone on the medial aspect of the ankle approximately 2.5 cm below the tip of the medial malleolus. The tuberosity is then easily palpable just anterior to this landmark. In the case of tuberosity fractures, pain may be exacerbated by passive eversion or active inversion of the foot.

Diagnostic Strategies: Radiology.: Standard foot radiographs usually demonstrate navicular fractures; however, CT or MRI may be required. Care is taken not to confuse the commonly occurring os tibiale externum, also called an accessory navicular bone, with an acute fracture (see Fig. 58-15).

Management.: Dorsal avulsion and tuberosity fractures not involving a significant amount of articular surface are usually treated with a walking cast for 4 to 6 weeks. Body fractures and displaced fractures involving more than 20% of the articular surface often require operative fixation.

Disposition.: Most navicular fractures are suitable for outpatient orthopedic follow-up; however, significant fractures, particularly if intra-articular, warrant orthopedic consultation in the ED. Navicular tuberosity fractures can be complicated by nonunion. Avascular necrosis and arthritis, particularly in body or other intra-articular fractures, are potential late sequelae.

Principles of Disease: Anatomy.: Collectively, the tarsometatarsal joints (see Fig. 58-14) are commonly called Lisfranc‘s joint. Any injury to this area, whether sprain, dislocation, or fracture-dislocation, is termed a Lisfranc injury. Knowledge of the anatomy of the Lisfranc joint complex is central to an understanding of these injuries.

Lisfranc’s joint is composed of the articulations of the bases of the first three metatarsals with their respective cuneiforms and the fourth and fifth metatarsals with the cuboid. In concert, the tarsometatarsal joints act to allow supination and pronation of the forefoot. The intrinsic stability of Lisfranc’s joint is provided by the bone architecture and associated ligaments. When viewed end on, the metatarsals have a trapezoidal shape and combine to form a transverse arch with the second metatarsal acting as the “keystone.” The second metatarsal is essential for the stability of the entire complex and is further buttressed by its snug articulation in a recess created by the three cuneiforms. Strong transverse intermetatarsal ligaments join the bases of the second through fifth metatarsals, and Lisfranc’s ligament joins the medial cuneiform with the second metatarsal base. Lisfranc’s joint is further supported by dorsal and plantar ligaments, the plantar fascia, and the insertions of the tibialis anterior and peroneus longus tendons at the first metatarsal base.

Pathophysiology.: Lisfranc injuries are uncommon, in part because tremendous energy is often required to disrupt this complex. Such injuries arise from three mechanisms: rotational forces, whereby the body twists around a fixed forefoot; axial loads, whereby the weight of the body drives the hindfoot into the bases of the metatarsals; and crush injuries. Because of the mechanisms involved, associated injuries, such as MTP joint dislocations, can occur. Most Lisfranc injuries are incurred in MVCs. Sports involving fixation of the forefoot (e.g., equestrian activities and windsurfing) also are associated with these injuries. Of note, one third of Lisfranc ligamentous injuries arise from seemingly trivial mechanisms such as stumbles or falls. Most Lisfranc injuries are closed.

Numerous classifications for displaced Lisfranc injuries exist, none of which aids in determining appropriate treatment or outcome.¹⁵² The most intuitive classification categorizes the direction of the dislocation in the horizontal plane (Fig. 58-23).^153–155 In homolateral injuries, all five metatarsals are displaced in the same direction. In isolated injuries, one or more metatarsals are displaced away from the others. In divergent injuries, the metatarsals are splayed outward in both the medial and the lateral directions. These injuries usually occur between the first and second metatarsals because of their lack of an intermetatarsal connection. A component of dorsal displacement also is commonly present in displaced Lisfranc injuries, whereas plantar displacement is uncommon because of the joint’s bone architecture and the strength of the plantar ligaments and fascia.

Because of ligamentous attachments, Lisfranc injuries almost invariably involve associated metatarsal fractures, usually of the second metatarsal base. Fractures of the cuboid, cuneiforms, and navicular also are common, occurring in more than one third of cases. Lisfranc injuries may be complicated by vascular injury because a critical branch of the dorsalis pedis artery dives between the first and second metatarsals to form the plantar arch. Trauma to this vessel can cause significant hemorrhage and, uncommonly, vascular compromise.

Clinical Features.: Most Lisfranc injuries are clinically obvious; however, findings may be subtle, and the true extent of the pathologic condition can easily be missed or misdiagnosed.¹⁵⁶ Apparently trivial fractures, if viewed in isolation, fail to reflect the serious soft tissue disruption that can be present. Some estimate that the diagnosis is missed on initial ED presentation in up to 20% of cases.^157–159

The clinical presentation varies with the extent of injury and displacement. Severe pain in the midfoot and inability to bear weight, particularly on the toes, are usual features. Paresthesias are occasionally present, and examination usually reveals edema and ecchymosis. In severe injuries, obvious deformity with forefoot abduction, equinus (a plantar-flexed position of the forefoot), and prominence of the medial tarsal area can be present. In addition, anteroposterior shortening and transverse broadening may be found. The dorsalis pedis pulse can be absent, or evidence of vascular compromise of the forefoot may be present. Typically, tenderness along the affected tarsometatarsal joints and pain with passive abduction and pronation of the forefoot are present, sometimes with pathologic mobility.

Diagnostic Strategies: Radiology.: Standard radiographic views of the foot usually are sufficient to diagnose injuries to the Lisfranc complex, although findings may be subtle (Fig. 58-24). The anteroposterior view identifies fractures and alignment, with the oblique view greatly aiding this assessment by eliminating overlap at the metatarsal bases. The lateral view shows the soft tissues and identifies any dorsal or plantar displacement. Weight-bearing (stress) radiographs may be helpful in uncertain cases,¹⁵⁷ and, although poorly studied, it has been suggested that up to 10% of Lisfranc injuries are undetectable without stress views.¹⁶⁰ In situations in which pain precludes weightbearing, regional anesthesia may facilitate obtaining weight-bearing radiographs. Comparison views are extremely helpful, and a 30-degree oblique view, in addition to the standard 45-degree oblique view, also may be of value. As is the case elsewhere in the hindfoot and midfoot, CT scanning has revolutionized the diagnosis and evaluation of Lisfranc injuries.¹⁶¹ Because of its ability to image ligamentous structures, MRI may be useful to predict Lisfranc joint complex instability.¹⁶²

An appreciation of normal radiographic anatomy is essential to assess Lisfranc injuries. Radiographs should be methodically examined, with assessment of alignment, bones, and soft tissues. The first four metatarsals should each line up with the respective tarsal articulation along the medial edge on anteroposterior and oblique radiographic views. The most consistent relationship is the alignment of the medial edge of the base of the second metatarsal with the medial edge of the middle cuneiform. Dorsal alignment of the tarsals with their respective metatarsals should be assessed on the lateral view.

Findings suggestive of a Lisfranc injury include widening between the first and second or second and third metatarsal bases and any fracture around Lisfranc’s joint. Fracture of the second metatarsal base (called a fleck sign), cuboid fractures, and cuneiform fractures are particularly common. A fracture of the second metatarsal base is virtually pathognomonic for occult tarsometatarsal joint disruption.

If a suspicious fracture is present and alignment appears normal, a spontaneously reduced dislocation may be present. In addition, plain radiographs may be normal in appearance in the setting of a typical history and tenderness over the tarsometatarsal joints, suggesting a sprain of the Lisfranc complex that may or may not be unstable. In either case, stress radiographs may be diagnostic.

Management.: Lisfranc injuries usually are treated with closed reduction and internal fixation with percutaneous Kirschner wires. This is followed by non–weight-bearing casting for 12 weeks and wearing of an orthotic for 1 year. Treatment of a sprain of the Lisfranc complex usually involves immobilization for 6 weeks in a below-knee walking cast.

Disposition.: Any obvious or suspected Lisfranc injury requires orthopedic consultation in the ED. Patients suspected of having a sprain of the Lisfranc complex require casting and orthopedic assessment on an outpatient basis, because operative fixation can be required. The incidence of complications with a Lisfranc injury depends on the timing of diagnosis and the degree of anatomic reduction achieved. Aggressive surgical management clearly improves outcome.

Delayed treatment or missed diagnosis of Lisfranc injuries can result in significant complications.¹⁶³ Degenerative arthritis is a common complication. Other potential complications include compartment syndrome, residual pain, unequal metatarsal pressure, loss of the metatarsal arch, and complex regional pain syndrome. Unstable sprains of the Lisfranc complex can result in biomechanical problems if untreated, and delayed presentations pose management challenges and often result in complications.¹⁶⁴

Metatarsal Shaft Fractures:

Clinical Features.: Metatarsal shaft fractures cause weight-bearing difficulty and tenderness, which usually is maximal on the plantar surface and can be difficult to localize if swelling is significant. Axial compression of the involved toe often is painful, and ecchymosis usually appears within 12 hours of injury. Rotational alignment should be assessed by evaluating the position and plane of the involved digit.

Diagnostic Strategies: Radiology.: Standard radiographs are sufficient to diagnose most metatarsal shaft fractures; however, radiographs usually are exposed for visualization of the talar bones, and the forefoot may be overpenetrated. Adjustment of penetration or coned views may be required for visualization of subtle fractures. Displacement and angulation, in both the sagittal and mediolateral planes, should be assessed.

Management.: Most undisplaced metatarsal shaft fractures of the second through fifth metatarsals are treated with a below-knee walking cast for 2 to 4 weeks. Early casted ambulation may be beneficial to healing and may reduce the incidence of complex regional pain syndrome. Although some practitioners recommend a non–weight-bearing cast for 4 to 6 weeks for these fractures, others suggest that a metatarsal pad, stiff shoes, and crutches, if needed, are sufficient. These various approaches attest to the fact that most nondisplaced metatarsal shaft fractures heal well regardless of the treatment.

The great toe metatarsal requires more aggressive management because of its biomechanical role and the stresses imposed on it during gait. Nondisplaced first metatarsal fractures should be treated with casting for 4 to 6 weeks.¹⁶⁷ For at least the first 3 weeks of this immobilization, if not the entire period, the patient should not bear weight.

Reduction should be considered in any metatarsal shaft fracture with more than 3 mm of displacement or 10 degrees of angulation. Closed reduction, with toe traps and countertraction at the ankle, is often successful. Non–weight-bearing casting for 4 to 6 weeks should follow. The indications for open reduction are controversial but generally include the presence of compartment syndrome, unstable fractures, open fractures, fractures that have failed closed reduction, and multiple fractures. These are treated with fixation with either Kirschner wires or plates.¹⁶⁷ In particular, displaced first and fifth metatarsal shaft fractures are commonly treated operatively. Major forefoot trauma, with crushing and multiple open metatarsal fractures, requires an aggressive approach with staged operative management.

Disposition.: Most undisplaced metatarsal shaft fractures are suitable for management without orthopedic referral. Orthopedic consultation in the ED should be obtained for patients with multiple or displaced fractures. Complications are rare in nondisplaced or minimally displaced metatarsal shaft fractures. Complex regional pain syndrome can occur and may be related to the unnecessary use of non–weight-bearing casting. Inadequate reduction, particularly in the sagittal plane, can lead to biomechanical problems and formation of painful callosities or metatarsalgia. Malunion in the mediolateral plane, particularly if involving the first or fifth metatarsal, can lead to development of pressure points, neuromas, or biomechanical problems. Delayed union, nonunion, compartment syndrome, and soft tissue complications occur uncommonly.

Metatarsal Head and Neck Fractures: Metatarsal head and neck fractures, although similar in their pathophysiology and assessment to shaft fractures, commonly are multiple and often result from direct trauma. Nondisplaced fractures may be treated with a walking cast for 4 to 6 weeks. Often these fractures are displaced, with the distal fragment pulled in a plantar and lateral direction by the flexor tendons, a finding best appreciated on oblique and lateral radiographic views. Precise realignment of neck and head fractures is important to maintain the transverse arch. Although reduction may be successful with toe traps, instability is common, and operative fixation is required more commonly than with shaft fractures. Most of these fractures warrant orthopedic consultation in the ED, particularly if they are displaced or intra-articular. Complications are similar to those seen with shaft fractures.

Metatarsal Base Fractures:

Fifth Metatarsal.: Jones fracture is a term often erroneously applied to any fracture of the fifth metatarsal base. The eponym is in reference to Sir Robert Jones, a physician who in 1902 described a fracture he sustained while dancing and a series of similar injuries. In reality, two distinct acute fractures can occur in the region of the fifth metatarsal base, and debate continues regarding which one Jones actually described.¹⁶⁸ More important than the terminology, these two fractures differ dramatically in their mechanism, treatment, and prognosis.¹⁶⁹

The more common, and benign, fracture at the fifth metatarsal base is of the tuberosity. Also called the styloid, the tuberosity is the bulge of the fifth metatarsal that is easily palpated over the lateral edge of the foot. It is fractured by a sudden inversion of a plantar-flexed foot. For decades, this fracture was thought to be caused by an avulsion at the insertion of the peroneus brevis tendon; however, it is now known that the plantar aponeurosis is responsible for the location and nature of this fracture.¹⁷⁰

Tuberosity fractures range from tiny flecks to lesions involving the entire tuberosity and usually are extra-articular, although they may extend into the cubometatarsal joint. Often these injuries masquerade as ankle sprains (see Fig. 58-12 and Box 58-2), making the fifth metatarsal base an important area to palpate in any twisting injury.

The more serious acute fracture at the base of the fifth metatarsal is a transverse fracture occurring at least 15 mm distal to the proximal end of the bone.¹⁶⁹ This diaphyseal fracture probably is a true Jones fracture and involves the fourth and fifth intermetatarsal articulations but not the cubometatarsal articulation. Diaphyseal fractures result from a complex combination of forces generated when a load is applied to the lateral forefoot in the absence of inversion.¹⁶⁹ Typically these occur in running and jumping sports. Further subclassification schemes of proximal diaphyseal fractures exist and can be helpful in determining management.¹⁵² Fifth metatarsal diaphyseal stress fractures can also occur and should be considered when a seemingly acute injury is preceded by a prodrome of pain in the region over weeks to months.^152,166

Clinical Features.: The assessment of metatarsal base fractures is similar to that described for fractures of the metatarsal shaft. Pain often is diffuse and difficult to localize in these injuries, with the exception of the easily palpable fifth metatarsal tuberosity. Passive inversion also may be painful with a fifth metatarsal base fracture.

Diagnostic Strategies: Radiology.: Standard radiographic views easily demonstrate most metatarsal base fractures. Radiographs should be carefully assessed for fracture angulation, displacement, and articular extension. If the fracture is intra-articular, an estimation of the percentage of articular surface involved is essential in determining management. In difficult cases, CT studies may be helpful.

With fractures of the first through fourth metatarsal bases, it is important to search for other radiologic clues to a Lisfranc injury. A fracture of the second metatarsal base is virtually pathognomonic for occult tarsometatarsal joint disruption. In assessment for a fifth metatarsal base fracture, differentiation between the tuberosity and diaphysis is essential (Fig. 58-25). Care should be taken not to misinterpret an os vesalianum or os peroneum for a fifth metatarsal base fracture (see Fig. 58-15). Standard ankle radiographs also demonstrate the fifth metatarsal base, and this area should be routinely scrutinized.

Management.: Nondisplaced extra-articular fractures of the first through fourth metatarsal bases usually are managed with a below-knee cast. Displaced fractures should be reduced and often require fixation. Intra-articular fractures, especially those of the first metatarsal, often lead to complications. Operative fixation may be required, even in nondisplaced intra-articular first metatarsal base fractures, if more than 25% of the articular surface is involved.

The management of fifth metatarsal base fractures depends on the type of fracture. Extra-articular tuberosity fractures, regardless of their size or degree of displacement, heal well and are managed symptomatically with a walking cast for 2 to 3 weeks, compression wrap, or stiff shoes.¹⁶⁸ Intra-articular tuberosity fractures involving more than 30% of the articular surface, or with more than 2 mm of displacement, may require fixation.¹⁶⁸ Nondisplaced intra-articular fractures usually are treated initially with non–weight-bearing casting for 6 to 8 weeks, followed by radiographic reassessment.¹⁶⁸ Immobilization for up to 6 months may be required for complete healing, and immediate fixation may be advisable in athletes.¹⁶⁹ Displaced fifth metatarsal diaphyseal fractures usually are managed operatively,¹⁷¹ and prolonged treatment may be necessary particularly for diaphyseal stress fractures.

Disposition.: Because they are rare and treatment varies, most first through fourth metatarsal base fractures require orthopedic assessment. Nondisplaced extra-articular fractures of the first through fourth metatarsal bases are suitable for orthopedic follow-up on an outpatient basis. Orthopedic consultation in the ED should be obtained in any other first through fourth metatarsal base fracture or if Lisfranc’s injury is suspected. Significant or displaced intra-articular fifth metatarsal tuberosity fractures or diaphyseal fractures warrant orthopedic evaluation in the ED.

Intra-articular metatarsal base fractures involving the first through fourth metatarsals can lead to post-traumatic arthritis requiring arthrodesis. Complications are rare in cases of fifth metatarsal tuberosity fractures, although fibrous nonunion of the fracture fragment can occur. Fifth metatarsal diaphyseal fractures are often complicated by delayed union, nonunion, or fracture recurrence, owing to poor healing subsequent to disruption of the metatarsal vascular supply. These complications occur in more than 50% of patients treated conservatively and often require aggressive surgical therapy and have prolonged healing times.

Principles of Disease: Pathophysiology.: Phalangeal fractures are the most common forefoot fracture. They usually arise from direct trauma, often the result of dropped heavy objects or stubbing the toe. Less commonly, indirect mechanisms involving twisting of the forefoot can lead to phalangeal fractures. Proximal phalanges are more commonly fractured than middle or distal phalanges, and the proximal phalanx of the fifth toe is most commonly injured. Fractures of the hallux often are displaced, whereas fractures of the lesser phalanges are often comminuted but less commonly displaced.

Clinical Features.: Although phalangeal fractures generally are considered minor injuries, they can lead to disabling sequelae and merit careful assessment.¹⁷² The patient with a phalangeal fracture has acute pain and swelling of the affected toe, often with difficulty ambulating or wearing shoes. Examination may reveal tenderness, crepitus, and reduced range of motion. A subungual hematoma often is present if the distal phalanx is involved, and open fractures are common.

Diagnostic Strategies: Radiology.: Standard radiographic views usually are sufficient to demonstrate phalangeal fractures, with the lateral view being most sensitive. Often the uninjured toes must be positioned out of the way for adequate radiographs to be obtained, and magnification radiographs occasionally are required. Angulation and joint involvement should be assessed.

Management.: Most phalangeal fractures are easily managed and heal well. Large and symptomatic subungual hematomas should be evacuated, and, on rare occasions, nail bed repair may be required. Nondisplaced lesser phalangeal fractures should be stabilized by “buddy-taping”—splinting the injured toe to an adjacent, ideally longer, toe with adhesive tape. Placement of gauze between the splinted toes is advisable to prevent skin maceration. Phalangeal fractures often remain painful for 2 to 3 weeks until stabilized by callus.

If significant displacement or angulation is present, reduction should be performed with manual traction or toe traps after digital block anesthesia. Moderate persistent angulation or displacement is acceptable if the clinical appearance of the toe remains satisfactory. Rarely, operative fixation of lesser phalangeal fractures is indicated, particularly in cases with severe rotatory deformity or in open fractures requiring débridement.

Nondisplaced phalangeal fractures involving the hallux are treated by buddy-taping, with a walking cast worn for 2 to 3 weeks if the toe is painful. Alternatives to standard casting techniques, such as the slipper cast, have also been described for phalangeal fractures.¹⁷³ Displaced phalangeal fractures of the hallux require reduction. If the reduction is inadequate or unstable, operative fixation may be indicated. Unless completely nondisplaced, most intra-articular fractures involving the hallux are treated with operative fixation, although this is an area of controversy.

Disposition.: Most phalangeal fractures do not require orthopedic evaluation; however, if displacement persists or causes cosmetic or functional concern, consultation is advised. Orthopedic consultation in the ED is advised for poorly reduced or intra-articular hallux fractures.

Complications of phalangeal fractures are uncommon. With intra-articular phalangeal fractures, particularly those involving the hallux, arthritis may be a late sequela, or fragments may require operative removal. Symptomatic angular malunion and osseous deformity can occur with phalangeal fractures, and exostectomy is sometimes required.

Principles of Disease: Pathophysiology.: Dislocations of the MTP joint are uncommon injuries because of the protection footwear provides and the inherent stability of MTP and IP joints. MTP joint dislocations can occur in any joint and in any direction. First MTP joint dislocations require large forces and usually result from MVCs. These injuries often are open and typically involve dorsal dislocations of the distal component caused by hyperextension of the MTP joint. Associated sesamoid fractures may be present. Complex dislocations, in which the sesamoids or local tendons prevent closed reduction, can occur. Second through fifth MTP dislocations usually are medial or lateral displacements that occur when the toe strikes or hooks an object. The most common is a lateral dislocation of the fifth MTP joint.

Clinical Features.: Dislocations of the MTP joint cause pain, swelling, and difficulty bearing weight on the ball of the foot. First MTP joint dislocations usually are obvious on clinical examination because the toe is angled upward with dorsal and proximal displacement of the proximal phalanx. This deformity leads to a striking prominence of the metatarsal head over the plantar surface. Skin tenting or a dimple may be present. Rarely the sesamoids are palpable dorsal to the metatarsal, indicating a complex dislocation. Dislocations of the lesser toes often are more subtle in presentation, and comparison with the uninjured foot may be helpful. Neurovascular compromise is rare.

Diagnostic Strategies: Radiology.: Dislocations of the MTP joint are well visualized on standard radiographic views of the foot. In first MTP joint dislocations, a double density often is present, caused by superimposition of the base of the proximal phalanx over the metatarsal head. Radiographs should be scrutinized for signs suggesting complex dislocation, such as the sesamoids lying between the two articular surfaces or dorsal to the metatarsal head.

Management.: Most MTP joint dislocations, particularly of the lesser toes, are easily reduced with longitudinal traction. Appropriate analgesia or local anesthesia should be administered before reduction is attempted. Dorsal dislocations of the first MTP joint can be more challenging and may require initial accentuation of the deformity in addition to longitudinal traction for reduction. Joint stability should be assessed and repeat radiographs obtained after reduction of an MTP joint dislocation. After reduction, a walking cast with a toe plate is worn for 3 weeks, followed by physiotherapy to ensure adequate range of motion. Alternatively, buddy-taping and an aluminum splint can be used for immobilization.

Disposition.: Most MTP joint dislocations can be managed without orthopedic consultation. If crepitus or obvious instability is present or postreduction radiographs show joint incongruity or an intra-articular fracture, orthopedic consultation should be obtained for possible fixation. First MTP joint dislocations that are open, show radiographic evidence of complexity, or do not easily reduce require orthopedic consultation in the ED, because open reduction may be required. Very rarely, MTP joint dislocations of the lesser toes require open reduction.

Complications are uncommon after MTP dislocations. Arthritis and reduced range of motion, particularly of the hallux, may occur. Dislocations for which the diagnosis is delayed for more than 3 weeks often are not amenable to closed reduction and may require metatarsal head excision.

Perspective.: Foot pain, particularly in the absence of obvious trauma, poses a diagnostic and therapeutic challenge. Plain radiographs commonly are normal in appearance, so the history and physical examination assume increased importance. Although a definitive diagnosis often is difficult to obtain in the ED, a structured approach aids in appropriate patient management and disposition. Most causes of foot pain are minor and self-limited, but the possibility of serious pathologic conditions (e.g., infection, arthritis, tumor) should be considered. Although orthopedic consultation in the ED is rarely required, orthopedic or sports medicine follow-up on an outpatient basis is indicated for selected cases.

Foot pain can be classified as acute, acute on chronic, or chronic and is best approached anatomically by localizing symptoms to the hindfoot, midfoot, or forefoot. Three conditions warrant specific mention.

Complex regional pain syndrome is a condition involving pain in the presence of trophic changes and vasomotor instability from inappropriate sympathetic nervous system activity and was previously termed “reflex sympathetic dystrophy.” Complex regional pain syndrome occurs months after trauma, which may be major, as in a Lisfranc injury, or relatively innocuous. It has many synonyms, including causalgia and Sudeck‘s atrophy, and produces pain of a diffuse burning, aching, or searing nature, together with evidence of vasomotor instability. Complex regional pain syndrome should be considered in the differential diagnosis for foot pain after trauma.

Another important consideration in patients with previous penetrating trauma is a retained foreign body. Foreign bodies can be a source of chronic drainage or chronic pain. The inciting trauma may have occurred years previously, and a history of the event may be difficult to extract, or such an event may be unknown to the patient.

Finally, stress fractures are an important consideration in the differential diagnosis for foot pain, particularly in athletes.

Hindfoot Pain.: Hindfoot pain is a common complaint that usually is the result of overuse rather than acute trauma.¹⁷⁵ Bone pain in the hindfoot necessitates consideration of talar or calcaneal stress fractures. A calcaneal stress fracture may be suspected when pain is elicited on squeezing the calcaneus mediolaterally. Another cause of bone pain is impingement by an os trigonum (see Fig. 58-15) or prominent lateral posterior talar process. The os trigonum syndrome involves pain during plantar flexion of the foot and is particularly common in ballet dancers. A bone scan may be required for diagnosis, and treatment is surgical.

Most patients with hindfoot pain describe subcalcaneal heel pain, a complaint with an extensive differential diagnosis.¹⁷⁶ The literature on this topic is conflicting and fraught with inconsistent terminology. The most common causes of subcalcaneal pain are plantar fasciitis, subcalcaneal bursitis, acute rupture of the plantar fascia, and nerve compression.

The plantar fascia is a tough layer of the sole that is functionally significant during foot strike and the early stance phase of walking. Plantar fasciitis, an overuse injury of insidious onset, usually begins with pain on first weightbearing in the morning or after prolonged sitting.¹⁷⁷ This progresses to persistent pain during gait. Pain and tenderness are localized to the medial aspect of the heel. Plantar fasciitis is particularly common in cavus feet, although the nature of this association is unclear.¹⁷⁸ Plain radiography is not diagnostic but shows a calcaneal spur in 50% of patients with plantar fasciitis. This is a stress-related ossification with a 16% incidence in asymptomatic persons and is not considered the primary cause of pain in plantar fasciitis. Rarely, fascial ossification (an os subcalcis) may be seen.

Plantar fasciitis is distinct from subcalcaneal bursitis, a condition with an identical presentation in which the pain is localized to the bursa directly below the calcaneus. Differentiating these two conditions can be difficult and usually is academic, because initial treatment is identical: a combination of avoiding precipitating conditions, rest, padding, orthotics, nonsteroidal anti-inflammatory drugs, and occasionally steroid injections. Extracorporeal shock wave therapy can be beneficial in refractory cases.¹⁷⁹ Very rarely, surgical release of the plantar fascia is required, a therapy that can be beneficial in either condition.

Plantar fascial rupture is a tear of the origin of the plantar fascia at the calcaneus. This injury usually occurs during the push-off phase of gait. Swelling may be noted, and typically pain is elicited by passive dorsiflexion of the hallux. Treatment is nonsurgical, often with a period of cast immobilization for symptomatic relief.

Compression of either the abductor digiti quinti nerve or the posterior tibial nerve (the so-called “tarsal tunnel syndrome”) can cause subcalcaneal heel pain.¹⁸⁰ Diagnosis of these conditions is difficult and is sometimes facilitated by assessing the impact of selective nerve block with local anesthesia. Initial treatment of these conditions is similar to that for plantar fasciitis, although local steroid injections or surgical release may be required. Other nerve entrapments also can occur in the hindfoot area.

Many tendons course through the hindfoot, particularly the anteromedial aspect, and tendinitis can occur. Other tendon pathologic conditions (e.g., ruptures, dislocations, retinacular injuries) should be considered because they can result in significant functional disability.

Midfoot Pain.: Isolated midfoot pain is less common than forefoot or hindfoot pain. Stress fractures are uncommon in the midfoot and most commonly involve the navicular. Other causes of midfoot pain include symptomatic accessory bones, particularly the accessory navicular, os tibiale externum, and os peroneum (see Fig. 58-15). An os tibiale externum is present in up to 14% of the normal population and is asymptomatic in most cases. This accessory bone can produce debilitating pain on the medial aspect of the midfoot. A bone scan facilitates diagnosis, and surgical excision may be necessary. An os peroneum is one of several conditions that can cause lateral plantar pain in the midfoot region. Localization of tenderness is aided by resisted plantar flexion, and treatment ranges from immobilization to surgical excision.

Forefoot Pain.: The forefoot is the site for a myriad of painful problems. Bunions, painful bursae, blisters, corns, calluses, hammertoes, and ingrown toenails all are diagnostically obvious but can pose therapeutic challenges. Many are the result of poor footwear or a biomechanical problem with the foot and respond to appropriate padding, avoidance of precipitants, and occasionally surgical intervention.

Metatarsalgia is an often used, although loosely defined, term referring to pain in the region of the metatarsal heads.¹⁸¹ This is a common presenting complaint with many potential causes. Metatarsal stress fractures are extremely common and should be considered in the differential diagnosis for any unexplained forefoot pain. Flexor or extensor tendinitis also can produce metatarsal area pain and is suggested when plain radiographs show areas of tendinous calcification. Arthritis, sesamoiditis, or a sesamoid stress fracture should be considered when pain occurs in the area of the hallux. “Turf toe” is MTP joint inflammation of the hallux resulting from repeated hyperextension stress.¹¹⁷ It usually responds to symptomatic measures but can be a significant and debilitating injury in some athletes, such as football players.

An important cause of unilateral metatarsalgia is a perineural fibrosis of the intermetatarsal plantar digital nerve, more commonly known as Morton‘s neuroma.¹⁸¹ This neuropathy of unknown cause was first described in 1876 and usually involves the second-third or third-fourth intermetatarsal space, causing lancinating pain with weightbearing. The pain may be associated with paresthesias and can radiate into the toes. In addition, “afterburn” pain can persist during rest. The pain of Morton’s neuroma is reproduced when structures of the affected interspace are pinched or when the metatarsal heads are compressed together. Hence, pain may occur intermittently with tight-fitting footwear (e.g., rock-climbing shoes, ski boots). Crepitus or a nodule may be palpable. Initial treatment usually involves a metatarsal pad and the use of shoes with a widened toe box. Surgical excision or neurolysis may be required if conservative management is unsuccessful.¹⁸²

Freiberg‘s disease is an osteochondrosis of the metatarsal head, usually involving the second metatarsal, and is another cause of pain in this area. Ingrown toenails are a common affliction that can occur in any toe, most commonly the hallux. Often the abnormality is perpetuated by short nail trimming, which affords the opportunity for a spicule of nail to grow under the nail fold.¹⁸³ Allowing the nail to grow out and providing local care usually will lead to resolution of the condition. Antibiotics are indicated if infection is present. Chronic or recurring ingrowth necessitates partial or complete excision of the nail and germinal ablation.¹⁸³