Browse the corpus

1862 SECTION 22: Orthopedics is squeezed. The diagnosis of Achilles tendon rupture can be made without radiographs. When the diagnosis is not clear, perform a bedside US or obtain an MRI of the Achilles tendon. The reliability of US is largely dependent on the operator’s skill. Initial care for Achilles tendon rupture involves immobilization from just below the knee to the metatarsals with the ankle in some plantarflexion. Crutches are necessary for non–weightbearing status. Ice and analgesics are also used. Refer patients with Achilles tendon rupture to an orthopedist or sports medicine specialist. Subsequent therapy involves either surgical repair of the ruptured tendon or immobilization and gradual physical therapy to regain range of motion. Immobilization is typically needed for 2 to 3 months. MEDIAL GASTROCNEMIUS MUSCLE STRAIN The medial gastrocnemius originates from the medial femoral condyle, crosses the knee, and joins the lateral gastrocnemius. The tendon complex of this muscle merges with that of the soleus muscle to form the Achilles tendon, which inserts on the calcaneus to act in plantarflexion of the foot. Injury to the medial gastrocnemius muscle usually occurs when a person forcefully plantarflexes the foot while the knee is extended, occurring when the gastrocnemius is at its maximal length. The typical patient is 40 to 60 years old and an intermittently active athlete. A sharp pain is sud denly felt in the calf as if a stick had struck the person. An audible “pop” may be heard. The pain is severe enough to cause an immediate cessation of the activity, as plantarflexion of the ankle is too painful. On examination, there may be asymmetric calf swelling and tender ness of the calf. The Achilles tendon is intact. The patient’s pain can be elicited by passive dorsiflexion of the ankle. Differential diagnosis can include deep vein thrombosis, ruptured Baker’s cyst, and compartment syndrome. Radiographs are not necessary for making the diagnosis. Nonurgent MRI can be obtained to confirm the diagnosis. Treatment includes immobilization with the foot maximally plantarflexed. Rest, ice, and elevation may decrease swelling. SHIN SPLINTS (EXERTIONAL COMPARTMENT SYNDROME) Shin splints is a complex syndrome characterized by aching, squeezing, or cramping in the anterior compartment of the leg. If pain does not resolve with rest or is out of proportion to examination, consider acute compartment syndrome. See Chapter 278 for further discussion. REFERENCES The complete reference list is available online at www.TintinalliEM.com. Ankle Injuries Talib Omer Margarita Santiago-Martinez INTRODUCTION AND EPIDEMIOLOGY Given the mobility of the ankle joint and our bipedal existence, ankle injuries are a common complaint. They represent about 4% of all visits to the ED. 1 Previous ankle sprain and participation in contact sports are risk factors for ankle injuries.2,3 ANATOMY The proximal part of the ankle mortise is composed of the distal fibula and tibia that fits on top of the talus. These bones are wider anteriorly than posteriorly. Joint stability is provided by medial and lateral malleoli extending on either side of the talus. The medial deltoid ligament, lateral ligament complex, and syndesmosis are the three distinct groups of ligaments that stabilize the ankle 4 (Figure 276-1). The deltoid liga ment is the strongest of these ligaments and is a thick, triangular band of tissue originating from the medial malleolus.

ither side of the talus. The medial deltoid ligament, lateral ligament complex, and syndesmosis are the three distinct groups of ligaments that stabilize the ankle 4 (Figure 276-1). The deltoid liga ment is the strongest of these ligaments and is a thick, triangular band of tissue originating from the medial malleolus. The lateral ligament complex consists of the lateral malleolus that attaches to the anterior and posterior aspects of the talus and calcaneus by the anterior talofibular, posterior talofibular, and calcaneofibular ligaments, respectively. This ligament complex, weaker than the deltoid and prone to inversion injuries, is commonly injured and represents 85% of all ankle sprains. 5 The Fibula Tibia Talus Anterior talofibular ligament Posterior talofibular ligament Calcaneofibular ligament Fibula Tibia Anterior inferior tibiofibular ligament Posterior inferior tibiofibular ligament Interosseous ligament Transverse ligament Tibia Tibiocalcaneal ligament Tibionavicular ligament Posterior tibiotalar ligament Anterior tibiotalar ligament Lateral view Medial view C Anterior and posterior view FIGURE 276-1. Ligaments of the ankle joint. A. The three lateral ligaments: the anterior and posterior talofibular ligaments and the calcaneofibular ligament. B. The four bands of the deltoid ligament: the anterior and posterior tibiotalar, the tibiocalcaneal, and the tibionavicular. C. Anterior and posterior view of the ankle syndesmosis. The ligaments of the syndesmosis are the anterior inferior tibiofibular ligament, the posterior inferior tibiofibular ligament, the transverse ligament, and the interosseous ligament, which connects the entire length of the tibia and fibula. CHAPTER Tintinalli_Sec22_p1767-1880.indd 1862 8/2/19 6:21 PM

nkle syndesmosis. The ligaments of the syndesmosis are the anterior inferior tibiofibular ligament, the posterior inferior tibiofibular ligament, the transverse ligament, and the interosseous ligament, which connects the entire length of the tibia and fibula. CHAPTER Tintinalli_Sec22_p1767-1880.indd 1862 8/2/19 6:21 PM CHAPTER 276: Ankle Injuries 1863 syndesmosis, which holds the tibia and fibula together, yet allows the fibula to rotate, is a group of four distinct ligaments attaching the distal tibia to the fibula just above the talus (Figure 276-1). While the fibula has no direct contact to the weight-bearing portion of the talus, the syndesmosis transmits about 16% of the axial load to the fibula. The ankle is considered a hinged joint, but ligamentous attachments allow for some rotation and translation within the mortise of the talar dome. 6 Branches of the sciatic nerve, the superficial peroneal, deep peroneal, peroneal, and tibial, innervate the four muscle groups of the ankle joint with branches of the popliteal artery serving as the blood supply (Figure 276-2). The tibialis anterior, extensor digitorum longus, and extensor hallucis longus muscles run over the anterior aspect of the joint and are responsible for dorsiflexion. Inversion is accomplished by the tibialis posterior, flexor digitorum longus, and flexor hallucis longus. The peroneus longus and brevis muscles, sharing a common synovial sheath held in place by a groove on the posterior aspect of the lateral malleolus and superior retinaculum, run laterally to evert and plantarflex the joint. Plantarflexion is primarily accomplished by the gastrocnemius and soleus muscles. CLINICAL FEATURES  HISTORY Understanding the mechanism and timing of the injury is important. Document these details along with any previous bony or soft tissue injuries. Patients with signs of neurovascular compromise, including coldness and numbness of the foot, a rapid onset of swelling, extreme pain, and complicating conditions such as diabetes, require urgent evaluation. 2 A normal-appearing ankle does not preclude the need for further inquiry. Due to the significant swelling that typically presents after acute injuries, examining the ankle is challenging but can be helped by elevation of the injured extremity and ice applied at triage. Peroneal spasms may mask any instability in the joint.  PHYSICAL EXAMINATION Place the patient on a stretcher to perform a thorough evaluation. A systematic approach to the examination decreases the chance of missed injuries. Starting with the skin and soft tissues, note any ecchymosis, abrasions, or swelling. Note the position, swelling, and skin integrity of the joint as well as any areas of tenderness or crepitus. Joints above and below the ankle need to be examined for any concomitant injuries. Suspect a Maisonneuve fracture (or fibulotibialis ligament tear) if there is tenderness of the fibular head or proximal fibular shaft. Palpate the area of obvious injury last. Test the functionality of the joint with both active and passive plantarflexion, dorsiflexion, and full range-of-motion exercises. Peroneal tendon injuries can occur from forced dorsiflexion, which presents as weakness on eversion ( Figure 276-3). 4 Check stabil ity in external rotation, varus, and valgus. Palpate the posterior aspects of the lateral and medial malleoli, starting proximally to the joint and working distally. If there is a concern for isolated fibular fractures, check for evidence of injury to the syndesmosis or deltoid ligament. Functional testing of the joint can reveal significant injuries. A positive anterior drawer test ( Figure 276-4) is indicative of a torn anterior talofibular ligament.

e joint and working distally. If there is a concern for isolated fibular fractures, check for evidence of injury to the syndesmosis or deltoid ligament. Functional testing of the joint can reveal significant injuries. A positive anterior drawer test ( Figure 276-4) is indicative of a torn anterior talofibular ligament. To perform the test, have the patient sit with the ankle in 10 to 15 degrees of plantar flexion, cup the heel in one hand, and provide countertraction to the tibia with the other hand while attempting to draw the heel forward. Increased subluxation of 2 mm or more compared to the uninjured side or visible dimpling of the anterior skin of the affected ankle indicates a significant anterior talofibular ligament injury. 4 A positive anterior drawer test, swelling, and a hematoma are signs of a grade III sprain. Syndesmosis injuries can be deceiving because the patient describes ankle pain, but there is typically little ankle edema or ecchymosis. The crossed-leg test (compressing the fibula toward the tibia just above the midpoint of the calf 7 ) can detect a syndesmosis injury and is indicated if pressure to the medial aspect of the knee elicits pain in the syndesmosis ( Figure 276-5). The squeeze test is performed by squeezing the calf just above the ankle joint. Pain indicates syndesmosis injury. Calcaneofibular ligament instability can be detected with the inversion stress test or talar tilt . 4 If the examination is uncomfortable for the patient, consider a hematoma block, sedation, or both to perform a more thorough examination. Examine areas in close proximity to the ankle as well. What may be described as an ankle injury may end up being an injury to the Achilles tendon or foot and cannot be excluded by ankle radiographic imaging. Tibialis posterior tendon Flexor digitorum longus tendon Tibial nerve Saphenous nerve Deep peroneal nerve Superficial peroneal nerve Posterior tibial artery Abductor hallucis muscle FIGURE 276-2. Neurovascular anatomy of ankle. Fibula Peroneal tendonsFIGURE 276-3. Peroneal tendon of the foot, lateral view. FIGURE 276-4. Technique for performing the anterior drawer stress test of the ankle. [Reproduced with permission from Simon RR, Sherman SC, Koenigsknecht SJ: Emergency Orthopedics, The Extremities, 5th ed. © 2007, McGraw-Hill Inc., New York.] Tintinalli_Sec22_p1767-1880.indd 1863 8/2/19 6:21 PM

the foot, lateral view. FIGURE 276-4. Technique for performing the anterior drawer stress test of the ankle. [Reproduced with permission from Simon RR, Sherman SC, Koenigsknecht SJ: Emergency Orthopedics, The Extremities, 5th ed. © 2007, McGraw-Hill Inc., New York.] Tintinalli_Sec22_p1767-1880.indd 1863 8/2/19 6:21 PM 1864 SECTION 22: Orthopedics Assess the integrity of the Achilles tendon. Fluoroquinolones and cor ticosteroids increase the risk of such an Achilles tendon injury. 8 Palpate the hindfoot and midfoot over the calcaneus, tarsals, and base of the fifth metatarsal to check for areas of tenderness that may require further investigation. Perform a neurovascular examination. Check dorsalis pedis and posterior tibial pulses and document digital capillary refill. Inability to dorsiflex the toes suggests a tibial nerve injury. Inability to plantarflex the great toe is suspicious for peroneal nerve injury. If there are any significantly displaced fractures or dislocations, immobilize the joint in a neutral position with a well-padded splint to reduce further soft tissue injury. Follow this with elevation and application of ice to reduce edema. Emergently reduce any displaced fractures or dislocations with neurovascular compromise (see later treatment section under “Dislocations”). DIAGNOSIS  IMAGING The Ottawa Ankle Rules for Ankle and Midfoot Injuries 9–13 are easily applied by physicians and other healthcare providers14 and can rule out ankle fractures without the need for radiography with high accuracy.15 The rules are summarized in Figure 276-6. (See Video: Ottawa Ankle Rules). They were originally developed for patients older than age 18 years who were able to cooperate, were not intoxicated, and had no distracting injuries or decreased sensation. See Chapter 141, “Pediatric Orthopedic Emergencies” for detailed discussion of the rules in children. 16,17 Assuming the patient does not have any bony tenderness, assess the ability to bear weight by having the patient take four steps, resulting in two transfers to and from the injured ankle. The initial studies demonstrated an approximately 30% reduction for the need of ankle radiographs. The standard ankle trauma series consists of three views: anteroposterior, 15-degree internal oblique, and lateral views. See Figure 276-7 for normal anatomy. About 95% of all ankle fractures can be detected with any two of these views. When there is an abnormal motion of the talus within the mortis, there is stress on the malleoli and ligaments, which causes the injury. Fractures above the talus and those that cause disruption of both sides of the joint have the potential to create an unstable injury. Instability of the joint is usually diagnosed based on plain radiographs because pain and swelling make it difficult to determine true stability of an acutely injured ankle. If radiographs are normal but there is concern about stability, weight-bearing ankle films can be helpful. Point-of-care ultrasound can detect Achilles tendon injuries 18 and ankle fractures.19 CT and MRI may play a role in better delineating pathology. Ideal imaging for a CT includes both axial and direct coronal images with sagittal reformations. To obtain these images, keep the ankle between neutral and 20 degrees of plantarflexion when possible, similar to that for plain radiographs. CT can be used for operative planning by ortho pedic surgeons and to evaluate comminuted fractures and complex bony injuries like pilon fractures and malunions. MRI can help define soft tissue, muscle, ligamentous, and tendon injuries and is used more in the outpatient setting for subacute and chronic pain presentations.

can be used for operative planning by ortho pedic surgeons and to evaluate comminuted fractures and complex bony injuries like pilon fractures and malunions. MRI can help define soft tissue, muscle, ligamentous, and tendon injuries and is used more in the outpatient setting for subacute and chronic pain presentations. TENDON INJURIES  CLINICAL FEATURES A peroneal tendon subluxation and dislocation occurs when there is a sudden hyperdorsiflexion of the foot in a position of eversion, as in skiing. The superior retinaculum, which holds the peroneal tendons in place, is torn from the posterolateral malleolus. This leads to a small avulsion fracture in more severe injuries with a dislocation or anterior subluxation of the peroneal tendon over the tip of the fibula. Consider this injury when there is ecchymosis or tenderness over the posterior FIGURE 276-5. The crossed-leg test. The affected leg is crossed over the opposite leg as demonstrated. If pain results at the arrow sites when pressure is applied to the medial side of the affected knee, the test is positive and indicates syndesmosis injury. [Copyright © 2010 by the American Orthopaedic Foot and Ankle Society, Inc., originally published in Foot & Ankle International in Kiter E, Bozkurt M: The crossed-leg test for examination of ankle syndemosis injuries. Foot Ankle Int 2: 187, 2005, and reproduced here with permission.] FIGURE 276-6. Ottawa Ankle Rules for Ankle and Midfoot Injuries. Ankle radiographs are required only if there is any pain in the malleolar zone or midfoot zone along with bony tenderness in any of these four locations or the inability to bear weight both immediately and in the ED. Tintinalli_Sec22_p1767-1880.indd 1864 8/2/19 6:21 PM CHAPTER 276: Ankle Injuries 1865 FIGURE 276-7. Normal ankle radiograph. A. Anteroposterior view. B. Lateral view. C. Oblique view. [Image used with permission of Robert DeMayo, MD.] Tintinalli_Sec22_p1767-1880.indd 1865 8/2/19 6:21 PM

TENDON INJURIES  CLINICAL FEATURES A peroneal tendon subluxation and dislocation occurs when there is a sudden hyperdorsiflexion of the foot in a position of eversion, as in skiing. The superior retinaculum, which holds the peroneal tendons in place, is torn from the posterolateral malleolus. This leads to a small avulsion fracture in more severe injuries with a dislocation or anterior subluxation of the peroneal tendon over the tip of the fibula. Consider this injury when there is ecchymosis or tenderness over the posterior FIGURE 276-5. The crossed-leg test. The affected leg is crossed over the opposite leg as demonstrated. If pain results at the arrow sites when pressure is applied to the medial side of the affected knee, the test is positive and indicates syndesmosis injury. [Copyright © 2010 by the American Orthopaedic Foot and Ankle Society, Inc., originally published in Foot & Ankle International in Kiter E, Bozkurt M: The crossed-leg test for examination of ankle syndemosis injuries. Foot Ankle Int 2: 187, 2005, and reproduced here with permission.] FIGURE 276-6. Ottawa Ankle Rules for Ankle and Midfoot Injuries. Ankle radiographs are required only if there is any pain in the malleolar zone or midfoot zone along with bony tenderness in any of these four locations or the inability to bear weight both immediately and in the ED. Tintinalli_Sec22_p1767-1880.indd 1864 8/2/19 6:21 PM CHAPTER 276: Ankle Injuries 1865 FIGURE 276-7. Normal ankle radiograph. A. Anteroposterior view. B. Lateral view. C. Oblique view. [Image used with permission of Robert DeMayo, MD.] Tintinalli_Sec22_p1767-1880.indd 1865 8/2/19 6:21 PM 1866 SECTION 22: Orthopedics edge of the lateral malleolus and no tenderness over the talofibular ligament. Achilles tendon ruptures occur with sudden plantarflexion of the foot. A complete tendon rupture will become apparent with palpation of a defect over the Achilles tendon and is identified by the Thompson test (Figure 276-8). Perform the Thompson test if there is tenderness or a defect. Place the patient prone on the stretcher and squeeze the calf on the affected side. Loss of plantarflexion indicates a complete Achilles tendon rupture. Ultrasound can also identify Achilles tendon ruptures (Figure 276-9).  TREATMENT The treatment for both types of tendon rupture is often operative repair, especially for those who wish to return to full activity. LIGAMENT INJURIES  CLINICAL FEATURES The most common type of ankle sprain is one to the lateral ankle . Typically, these are minor and are due to an inversion injury when the ankle is plantarflexed. Sprains are categorized into three grades. Grade I involves no tearing of the ligaments with minimal functional loss, pain, swelling, and ecchymosis. Weight bearing is tolerable. Grade II sprains occur with a partial tear and result in some loss of functional ability. These tend to be more painful, with swelling, ecchymosis, and difficulty bearing weight. Grade III sprains result from a complete tear, with sig nificant functional loss, pain, swelling, bruising, and almost a universal inability to bear weight. 21 However, joint stability is the primary deter minant of a treatment plan for a sprain. An isolated sprain of the medial deltoid ligament is rare. Medial deltoid ligament tears are usually associated with a fibular fracture or tear of the tibial-fibular syndesmosis from an eversion injury. If there is significant medial malleolus tenderness and swelling, suspect a Maisonneuve fracture of the proximal fibula and fibular shaft. Negative radiographs should suggest syndesmosis tears. Injuries to the tibiofibular syndesmotic complex are associated with hyperdorsiflexion injuries when the talus moves superiorly and separates the tibia and fibula. This leads to a partial or complete tear of the syndesmosis with complaints of pain just above the talus. If there is concern for an unstable ligamentous injury, weight-bearing views of the ankle can help diagnosis—an unstable ligamentous injury may demonstrate talar shift.  TREATMENT The immediate goals are to decrease pain and swelling and protect ligaments from further injury. The PRICE protocol (protection, rest, ice, compression, elevation) involves elevating the ankle and protecting it with a compressive device along with applying ice and resting up to 72 hours to allow the ligaments to heal. 3 There is controversy as to whether or not early immobilization versus functional treatment results in the best outcomes. There is a trend toward favoring early functional treatment over immobilization. 22 Patients returned to mobility anywhere between 4.6 and 7.1 days sooner with functional treatment when com pared with immobilization. 23 Functional treatment usually consists of three phases: (1) PRICE protocol within the first 24 hours of injury; (2) motion and strength exercises to begin within 48 to 72 hours; and (3) endurance training, focused toward specific sports when applicable, and training to improve balance after the second phase begins. FIGURE 276-8. Thompson test.

ally consists of three phases: (1) PRICE protocol within the first 24 hours of injury; (2) motion and strength exercises to begin within 48 to 72 hours; and (3) endurance training, focused toward specific sports when applicable, and training to improve balance after the second phase begins. FIGURE 276-8. Thompson test. There is no plantarflexion with squeezing the calf of the affected leg, or less plantarflexion compared with the normal leg. [Adapted with permission from Stone CK, Humphries RL. Current Diagnosis and Treatment Emergency Medicine, 7th ed. Copyright @ The McGraw Hill Companies, 2011. Figure 28-20.] FIGURE 276-9. Point-of-care ultrasound of Achilles tendon. A. Unaffected side. B. Ruptured Achilles tendon. [Used with permission of Talib Omer, MD, and Division of Emergency Ultrasound at LAC+USC Medical Center.] Tintinalli_Sec22_p1767-1880.indd 1866 8/2/19 6:21 PM

ght @ The McGraw Hill Companies, 2011. Figure 28-20.] FIGURE 276-9. Point-of-care ultrasound of Achilles tendon. A. Unaffected side. B. Ruptured Achilles tendon. [Used with permission of Talib Omer, MD, and Division of Emergency Ultrasound at LAC+USC Medical Center.] Tintinalli_Sec22_p1767-1880.indd 1866 8/2/19 6:21 PM CHAPTER 276: Ankle Injuries 1867 In patients with a lateral ligament sprain, a stable joint, and the ability to bear weight, treatment consists of analgesics, an elastic bandage or ankle brace, and no sports engagement, with follow-up in a week if no improvement. There is consensus among reviews that bracing is effective at preventing a recurrence of an ankle sprain. 24 For patients who are unable to bear weight but have a stable joint, provide an ankle brace and crutches and have them follow up with either their primary care provider or orthopedic surgeon within 1 week for repeat evaluation. Given the trend for early immobilization, functional braces, such as semirigid (e.g., Aircast ) and soft, lace-up braces, are commonly used. There is no consensus as to which leads to a more favorable outcome,25 although early rehabilitation of low-grade ankle sprains results in a good outcome. 26 Another option is an inflatable cast boot (also called a walking fracture boot or Aircast boot) that molds to the foot with inflatable air bladders. This device can also be used for stable ankle fractures. Treat medial ligament sprains with PRICE and early referral to an orthopedic surgeon given the risk for undetected underlying fractures. Consider early orthopedic referral for syndesmotic complex sprains given the expected prolonged recovery time. Refer patients with an unstable joint to an orthopedic surgeon after placement of a posterior splint for stabilization . Establish con tact with the orthopedic surgeon early because the timing of treatment and follow-up is ultimately at his or her discretion. There is no consensus as to whether surgery versus conservative treatment results in more favorable outcomes. Cryotherapy with ice will help decrease pain and limit swelling and should be applied directly to the ankle or splint but not left on for >20 minutes at a time. Therapeutic ultrasonography is not helpful. DISLOCATIONS  CLINICAL FEATURES Most ankle dislocations are associated with a fracture and can occur in one of four planes. Posterior dislocations are the most common and occur with a backward force on the plantarflexed foot, usually resulting in rupture of the tibiofibular ligaments or a lateral malleolus fracture. The less common anterior dislocation results from a force on the dorsiflexed foot with an associated anterior tibial fracture. A lateral dislocation results in ligamentous disruption and fracture of one or both malleoli (Figure 276-10). An axial compression force can drive the talus upward with an associated fracture of the talar dome and disruption of the syndesmosis.  TREATMENT There is a significant concern for neurovascular compromise. Check carefully for an open fracture in these instances. If the patient has intact pulses, dislocations associated with fractures should be reduced by an orthopedic surgeon. If vascular compromise is present, as evidenced by a dusky foot or absent pulses, or there is tenting of the skin, an imme diate reduction by the emergency physician is warranted without any prereduction radiographs. First provide appropriate sedation and analgesia before attempts at reduction. Grasp the heel and foot with both hands, and gently apply traction and rotation opposite to the direction of the mechanism of injury. Confirm pulses and distal perfusion, and then apply a splint and elevate the foot while waiting for orthopedic evaluation. Confirm and document distal perfusion again after splint application.

the heel and foot with both hands, and gently apply traction and rotation opposite to the direction of the mechanism of injury. Confirm pulses and distal perfusion, and then apply a splint and elevate the foot while waiting for orthopedic evaluation. Confirm and document distal perfusion again after splint application. Any dislocations that cannot be reduced using closed techniques will require open reduction. FIGURE 276-10. Open fracture with dislocation. A. Anteroposterior view. B. Lateral view. [Image used with permission of Robert DeMayo, MD.] Tintinalli_Sec22_p1767-1880.indd 1867 8/2/19 6:21 PM 1868 SECTION 22: Orthopedics Peroneus brevis muscle and tendon Peroneus longus tendon Tibialis anterior muscle and tendon Extensor hallucis muscle and tendon Extensor digitorum muscle and tendon FIGURE 276-11. Muscles of the ankle. FIGURE 276-12. Bimalleolar fracture. A. Anteroposterior view. B. Lateral view. [Image used with permission of Robert DeMayo, MD.] MUSCULAR INJURIES  CLINICAL FEATURES Strains are injuries to muscle or tendons not usually associated with a specific injury but due to repetitive stress and overuse. Common muscles and tendons involved include the extensor digitorum longus, extensor hallucis longus, peroneus brevis and longus, and anterior tibial tendon (Figure 276-11). Strains can be due to athletics or poorly fitting footwear. Contusions are usually caused by direct trauma from a projectile like a baseball or hockey puck. Fractures associated with contusions are rare and usually involve only the bony cortex.  TREATMENT For overuse injuries, analgesics, especially NSAIDs, will help, along with rest and cessation of the activities that are causing the strain. Targeted exercises may help in the recovery as well. Contusions are treated symptomatically with analgesia and ice. FRACTURES  CLINICAL FEATURES Radiographically, ankle fractures are described as unimalleolar, bimal leolar (Figure 276-12), and trimalleolar (Figure 276-13). A bimalleolar fracture is fracture of the lateral and medial malleoli; trimalleolar frac ture additionally involves the posterior malleolus. Tintinalli_Sec22_p1767-1880.indd 1868 8/2/19 6:22 PM

diographically, ankle fractures are described as unimalleolar, bimal leolar (Figure 276-12), and trimalleolar (Figure 276-13). A bimalleolar fracture is fracture of the lateral and medial malleoli; trimalleolar frac ture additionally involves the posterior malleolus. Tintinalli_Sec22_p1767-1880.indd 1868 8/2/19 6:22 PM CHAPTER 276: Ankle Injuries 1869 The ankle consists of a ring of bone and ligaments around the talus. The ring is composed of the tibia, tibiofibular ligament, fibula, lateral and medial ankle ligaments, and calcaneus.27 A single ring disruption is typically a stable injury. Injuries involving two or more components of the ring are unstable injuries and usually need surgical fixation. The Danis-Weber and Lauge-Hansen schemes are used by orthopedic surgeons to classify ankle fractures and help determine surgical repair. The Danis-Weber system classifies fracture patterns based on the level of the fracture of the fibula. 4 The Lauge-Hansen system classifies fractures based on the position of the foot at the time of injury. 28 Critical aspects of the examination for ankle fractures are summa rized in Table 276-1.  TREATMENT The goal is to restore the anatomic relationship of the ankle, maintain reduction during the healing, and mobilize the ankle early. Treat small fibular avulsion fractures as stable ankle sprains (see earlier section, “Ligament Injuries”) if they are minimally displaced (<3 mm in diameter) and there is no sign of medial ligament injury. Most other ankle fractures require immobilization by either cast alone or surgical repair and casting. 29,30 Severe comminuted fractures are at risk for compartment syndrome, fat emboli, and poor healing. Urgent orthopedic consultation in the ED is necessary. Until definitive fracture treatment can be provided, apply a posterior splint and stirrup and keep the patient non–weight bearing (see Chapter 267, “Initial Evaluation and Management of Orthopedic Injuries”). Provide analgesics, and remind the patient to elevate the leg and apply ice. Table 276-2 provides guidelines for orthopedic consultation and follow-up. TABLE 276-1 Associated and Occult Injuries of the Ankle Injury Clinical Suspicion Confirmatory Test Maisonneuve fracture Examine proximal fibula and shaft, tenderness to palpation; proximal fracture and syndesmosis tear indicate unstable fracture Fibula radiograph Peroneal tendon dislocation Palpable anterior tendon dislocation or subluxation Clinical examination Usually identified in followup of ankle sprains

y Test Maisonneuve fracture Examine proximal fibula and shaft, tenderness to palpation; proximal fracture and syndesmosis tear indicate unstable fracture Fibula radiograph Peroneal tendon dislocation Palpable anterior tendon dislocation or subluxation Clinical examination Usually identified in followup of ankle sprains Osteochondral injuries Diffuse ankle swelling, passive plantarflexion Ankle mortise view/CT Syndesmosis tear Significant ankle pain, positive squeeze test Widened mortise with weight bearing Anterior calcaneal process fracture Tenderness more inferoanterior than a typical ankle sprain Lateral ankle radiograph/CT Lateral talar process fracture Tenderness just distal to the tip of fibula Ankle mortise view/CT Os trigonum Tenderness anterior to Achilles tendon Lateral ankle radiograph FIGURE 276-13. Trimalleolar fracture. A. Anteroposterior view. B. Lateral view. [Image used with permission of Robert DeMayo, MD.] Tintinalli_Sec22_p1767-1880.indd 1869 8/2/19 6:22 PM