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904 SECTION 12: Pediatrics TABLE 140-3 AEIOU TIPS: A Mnemonic for Pediatric Altered Mental Status A Alcohol. Ethanol. Isopropyl alcohol. Methanol. Concurrent hypoglycemia is common. Acid-base and metabolic. Hypotonic and hypertonic dehydration. Hepatic dysfunction, inborn errors of metabolism. Arrhythmia/cardiogenic. Stokes-Adams, supraventricular tachycardia, aortic stenosis, heart block, pericardial tamponade. E Encephalopathy. Reye’s syndrome. Parainfectious encephalomyelitis. Autoimmune encephalitis, such as Anti-N-methyl-d-aspartate (Anti-NMDA) receptor encephalitis.12 Posterior reversible encephalopathy syndrome (PRES) may be associated with hypertension, autoimmune disease, and Henoch-Schönlein purpura (HSP). 13 Endocrinopathy. Addison’s disease can present with AMS or psychosis. Thyrotoxicosis can present with ventricular dysrhythmias. Pheochromocytoma can present with hypertensive encephalopathy. Electrolytes. Hypo-/hypernatremia and disorders of calcium, magnesium, and phosphorus can produce AMS. I Insulin. AMS from hyperglycemia is seen in severe diabetic ketoacidosis, as well as hyperglycemic hyperosmolar syndrome. Hypoglycemia can be the result of many disorders. Irritability, confusion, seizures, and coma can occur with blood glucose levels <40 milligrams/dL (2.22 mmol/L). Intussusception. AMS may be the initial presenting symptom. O Opiates. Common household exposures are to Lomotil® (diphenoxylate hydrochloride and atropine sulfate), Imodium® (loperamide), diphenoxylate, and dextromethorphan. Clonidine, an α-agonist, can also produce similar symptoms. Oxygen. Disorders of airway, breathing, or circulation may adversely affect oxygen delivery to the brain; hypercapnia from primary lung disease or neurologic dysfunction also may result in AMS. U Uremia. Hemolytic-uremic syndrome can produce AMS in addition to abdominal pain. Thrombocytopenic purpura and hemolytic anemia also can cause AMS. In children with chronic renal failure, neurologic dysfunction may develop secondary to stroke, hypertension, or metabolic derangements. T Trauma. Hypovolemia or hemorrhage from multisystem trauma may lead to insufficient cerebral perfusion and result in AMS. Consider concussion, hemorrhage, contusion, epidural or subdural hematoma. Consider nonaccidental trauma. Tumor. Primary, metastatic, or meningeal leukemic infiltration. Intracerebral tumors commonly produce focal neurologic signs, and posterior fossa tumors typically block the ventricular system and create signs and symptoms of hydrocephalus. Shunt malfunction should be considered among patients with a ventriculoperitoneal shunt for hydrocephalus. Thermal. Hypo- or hyperthermia. Progressive hypothermia leads to insidious AMS. I Infection. Bacterial meningitis, encephalitis, and brain abscess usually present with fevers. Brain abscess is characterized by fever and headache before AMS changes. Presenting symptoms also include generalized or focal seizures. Any systemic infection associated with vasculitis or shock may lead to AMS secondary to cerebral hypoperfusion. Intracerebral vascular disorders. Subarachnoid, intracerebral, or intraventricular hemorrhages can be seen with trauma, ruptured aneurysm, or arteriovenous malformations. Venous thrombosis can follow severe dehydration or pyogenic infection of the mastoid, orbit, middle ear, or sinuses. Arterial thrombosis is uncommon in children, except in those with homocystinuria.

ntracerebral, or intraventricular hemorrhages can be seen with trauma, ruptured aneurysm, or arteriovenous malformations. Venous thrombosis can follow severe dehydration or pyogenic infection of the mastoid, orbit, middle ear, or sinuses. Arterial thrombosis is uncommon in children, except in those with homocystinuria. Intracerebral and intraventricular hemorrhages may follow birth asphyxia or trauma in neonates, but in older children, they may signify a congenital or acquired coagulopathy. Cerebral emboli from bacterial endocarditis may cause AMS. Acute confusional migraine may be associated with profound alterations in consciousness. Children with sickle cell anemia can develop cerebral thrombosis, status epilepticus, and coma. P Psychogenic. Characterized by decreased responsiveness with normal neurologic examination including oculovestibular reflexes. Psychogenic unresponsiveness may be a conversion reaction, an adjustment reaction, a panic state, or malingering. Poisoning/ingestion. Drugs, toxins, or illicit substances can be ingested by accident, through neglect or abuse, or in a suicidal gesture. Intentional ingestion of recreational drugs, including synthetic cannabinoids, may be considered. S Seizure. Generalized motor seizures and absence status epilepticus are often associated with prolonged unresponsiveness in children. 15 In a child with a history of seizures who presents with AMS, consider nonconvulsive status epilepticus. Febrile seizures are seen in children aged 6 months to 6 years. Abbreviation: AMS = altered mental status. TABLE 140-4 General Treatment of Altered Mental Status •  Assess  airway, breathing, and circulation. •  Immobilize  cervical spine for suspected trauma. •  Initiate  continuous pulse oximetry; consider capnometry; administer oxygen. •   Give dextrose for hypoglycemia; for children, give 25% dextrose in water 2 mL/kg IV; for newborns, give 5 mL/kg of 10% dextrose in water. •   Provide fluid resuscitation, 20 mL/kg of isotonic crystalloid, and repeat to total of 60 mL/kg as needed. •   Administer broad-spectrum antibiotics for suspected sepsis or meningitis. •   Give naloxone for suspected opiate or clonidine overdose, 0.01 to 0.1 milligram/kg IV every 2 min. •   Administer flumazenil for suspected pure benzodiazepine overdose, 0.01 milligram/kg IV. •   Control seizures with benzodiazepines (lorazepam, 0.1 milligram/kg IV; diazepam, 0.1 milligram/kg IV; or midazolam, 0.1 milligram/kg IV). •   Prevent/treat hypothermia with heat lamps during resuscitation; treat hyperthermia. who are evaluated for altered mental status and discharged home should have a repeat evaluation within 24 hours of discharge. REFERENCES The complete reference list is available online at www.TintinalliEM.com. unit or in an intensive care unit. 6 Only patients with transient, revers ible causes may be treated, monitored in the ED, and discharged after observation and a return to their baseline mental status. Patients who are discharged (e.g., those with a closed head injury or simple febrile seizure) should receive disease-specific discharge instructions. Children Pediatric Orthopedic Emergencies Kathy Boutis GENERAL PRINCIPLES The anatomy of the pediatric musculoskeletal system is unique and reflects the active growth and development that occurs during child hood. Fracture classification, treatment approach, and types of compli cations are directly related to this unique anatomy. In general, both injury patterns and treatment approaches in children in whom closure CHAPTER Tintinalli_Sec12_p0669-0996.indd 904 8/2/19 7:56 PM

ve growth and development that occurs during child hood. Fracture classification, treatment approach, and types of compli cations are directly related to this unique anatomy. In general, both injury patterns and treatment approaches in children in whom closure CHAPTER Tintinalli_Sec12_p0669-0996.indd 904 8/2/19 7:56 PM CHAPTER 141: Pediatric Orthopedic Emergencies 905 ligaments tolerate mechanical forces better than the weaker physes. Therefore, apophyseal detachments or epiphyseal fractures are much more common than ligamentous injuries during childhood. FRACTURE PATTERNS  FRACTURES INVOLVING THE PHYSIS The Salter and Harris classification system (see Figure 267-7) is based on the relationship of the fracture line to the physis and the prognosis for growth disturbance. Salter-Harris Type I Fractures Type I physeal injuries occur when the epiphysis separates from the metaphysis. The cleavage is through the hypertrophic cell zone of the physis, with the reproductive cells of the physis remaining with the epiphysis. There are no associated fragments of bone, as the thick periosteal attachments surrounding the physis remain intact. The epiphysis may, however, displace from the metaphysis. Type I injuries have a very low incidence of growth disturbances. Suspect a Salter-Harris type I injury when there is point tenderness over a physis. Radiographic findings are typically subtle or absent, and soft tissue swelling or a joint effusion may be the only abnormality. Epiphyseal displacement can usually be appreciated on radiographs in one or more views (Figure 141-2); however, in the absence of epiphyseal displacement, the diagnosis is a clinical one. Salter-Harris Type II Fractures In a type II injury, the fracture line extends a variable distance along the hypertrophic cell zone of the physis and then out through a piece of metaphyseal bone. The periosteum overlying the metaphyseal fragment remains intact, whereas the periosteum on the opposite side of the fracture is torn away from the diaphysis while remaining adherent to the epiphysis. Growth is preserved because the reproductive layers of the physis maintain their position with the epiphysis and the epiphyseal circulation. Diagnosis is made radiographically by noting a triangular-shaped fragment of metaphysis that is not associated with discernible injury to the epiphysis (Figures 141-3 and 141-4). Salter-Harris Type III Fractures Type III physeal injuries are intraarticular. The fracture line extends intra-articularly from the epiphysis, through the hypertrophic zone of the physis, with the cleavage plane continuing along the physis to the periphery. The prognosis for subse quent bone growth relates to the preservation of circulation to the epiphyseal bone fragment; however, the prognosis is usually quite favorable. Periosteum Physis (growth plate) Greater trochanteric apophysis Lesser trochanteric apophysis Proximal femoral apophysis Physis (growth plate) Diaphysis Metaphysis Distal femoral apophysis FIGURE 141-1. The anatomy of the pediatric long bone as demonstrated by the femur. Longitudinal growth occurs at the physes (growth plates) located at either end. Bony promi nences that serve as sites of muscular or ligamentous attachment are known as apophyses (e.g., greater trochanteric apophysis). FIGURE 141-2. Salter-Harris type I fracture of distal tibia. Anteroposterior radiograph showing widened physeal line of distal tibia with malalignment of epiphysis with metaphysis (arrow). [Photo used with permission of Karen Black, BC Children’s Hospital, Vancouver.] of the physes (growth plates) has already occurred are similar to those of the adult. Therefore, the major focus of this chapter is directed at injuries occurring in the prepubescent child with open physes.

piphysis with metaphysis (arrow). [Photo used with permission of Karen Black, BC Children’s Hospital, Vancouver.] of the physes (growth plates) has already occurred are similar to those of the adult. Therefore, the major focus of this chapter is directed at injuries occurring in the prepubescent child with open physes. In addition, some diseases specific to children that cause nontraumatic musculoskeletal complaints are covered. The long bones of children consist of discrete anatomic areas. The physis is an area of growth cartilage and may occur at one (e.g., the phalanges) or both (e.g., the tibia and the femur) ends of a long bone. The area of bone between a physis and the adjacent joint is termed the epiphysis. An apophysis is an outgrowth of bone, usually with its own ossification center in childhood that often serves as a point for muscle or ligament attachment. The midshaft of a long bone is referred to as the diaphysis. The metaphysis of a long bone represents the area between the diaphysis and the physis ( Figure 141-1; see Chapter 267, “Initial Evaluation and Management of Orthopedic Injuries”). The long bones of children are less dense and more porous than the long bones of adults. Pediatric long bones respond to mechanical stress by bowing and buckling rather than fracturing through and through like fractures in adult bones. The periosteum of the diaphysis and the metaphysis is thick in children and is continuous from the metaphysis to the epiphysis, surrounding and protecting the mechanically weaker physis. The weakness of the physis is in part related to the reduced oxygen ten sion found in the hypertrophic zone of the physis. This hypertrophic zone is the location of frequent fractures within the physis. The physis is also sensitive to alterations in the blood supply, and physeal injuries can result in growth disturbance. Compression forces alone may also affect bone growth. This is particularly true when compression forces are applied to the epiphyseal side of the physis. The injury to bone growth caused by compression results from interruption of the epiphyseal cir culation to the reproductive cells of the physis. The growth of the musculoskeletal system and its response to injury are influenced by the growth of muscle and connective tissue. The liga ments of children are stronger and more compliant than in adults, and Tintinalli_Sec12_p0669-0996.indd 905 8/2/19 7:56 PM

yseal cir culation to the reproductive cells of the physis. The growth of the musculoskeletal system and its response to injury are influenced by the growth of muscle and connective tissue. The liga ments of children are stronger and more compliant than in adults, and Tintinalli_Sec12_p0669-0996.indd 905 8/2/19 7:56 PM 906 SECTION 12: Pediatrics The diagnosis of a type III injury is made radiographically and is based on the appearance of an epiphyseal fragment not associated with an apparent metaphyseal fracture. There may or may not be an associated periosteal injury (Figure 141-5). Occasionally, additional imaging with CT or MRI is used to better evaluate the extent of fracture and articular surface involvement. Salter-Harris Type IV Fractures In type IV injuries, the fracture line originates at the articular surface, extends through the epiphysis and the entire thickness of the physis, and continues through the metaphysis (Figure 141-6). The risk of growth disturbance with this type of fracture is significant, and reduction must be precise. The diagnosis of a type IV injury is made radiographically upon identification of epiphyseal and metaphyseal fragments. Salter-Harris Type V Fractures Type V injuries typically involve the knee or ankle and are the result of a profound compressive force trans mitted to the physis, resulting in crushing of the chondrocytes in both the reserve and proliferative zones. Displacement of the epiphysis is usually only minimal despite the significant damage to the physis. The diagnosis of a type V injury may be difficult initially, leading to a lack of appreciation of the severity of the injury. An initial diagnosis of a sprain or a type I physeal fracture may prove incorrect in view of subsequent development of premature growth arrest during follow-up. Radiographs may appear normal or may demonstrate focal narrowing of the physeal plate. There is also typically a joint effusion. The history, however, should point to a type V injury, as these injuries are typically associated with a significant mechanism.  TORUS FRACTURES Compressive forces often result in a bulging or buckling of the perios teum rather than a more complete fracture line. Cortical, or torus, fractures are so named to describe prominence or bulging of the bony cortex, usually involving the metaphysis. These are also called buckle fractures. A simple torus fracture will not produce a visible deformity to the shape of the extremity; however, there is typically soft tissue swelling and point tenderness over the bony injury. FIGURE 141-3. Salter-Harris type II fracture of distal tibia. Lateral radiograph illustrat ing fracture extending through physeal growth plate and metaphysis with dorsal displace ment of epiphysis requiring reduction. [Photo used with permission of Wake Medical Center, Raleigh, NC.] FIGURE 141-4. Salter-Harris type II fracture of distal tibia. CT image illustrating fracture extending through physeal growth plate and metaphysis ( arrow). [Image used with permis sion of Wake Medical Center, Raleigh, NC.] FIGURE 141-5. A radiograph of a Salter-Harris type III fracture of the distal tibia, also known as a Tillaux fracture. Note the intra-articular component extending through the growth plate and the medial epiphysis of the tibia. [Reproduced with permission from Strange GR, Ahrens WR, Schafermeyer RW, Wiebe RA: Pediatric Emergency Medicine, 3rd ed. McGraw-Hill, Inc., 2009. Fig 38-8.] Tintinalli_Sec12_p0669-0996.indd 906 8/2/19 7:56 PM

e. Note the intra-articular component extending through the growth plate and the medial epiphysis of the tibia. [Reproduced with permission from Strange GR, Ahrens WR, Schafermeyer RW, Wiebe RA: Pediatric Emergency Medicine, 3rd ed. McGraw-Hill, Inc., 2009. Fig 38-8.] Tintinalli_Sec12_p0669-0996.indd 906 8/2/19 7:56 PM CHAPTER 141: Pediatric Orthopedic Emergencies 907 Radiographically, the torus fracture may be subtle. Carefully inspect the contour of the metaphyseal flare. Any asymmetry, bulging, or deviation of the cortical margin indicates a torus fracture. Soft tissue swelling is also usually evident (Figure 141-7). Torus fractures are not associated with angulation, displacement, or rotational abnormalities, so reduction is not necessary.  GREENSTICK FRACTURES A greenstick fracture is characterized by cortical disruption and perios teal tearing on the convex side of the bone, with an intact periosteum and on the concave side of the fracture. Greenstick fractures are more stable and somewhat less painful than complete fractures because the area of intact periosteum limits bony displacement (Figure 141-8).  PLASTIC DEFORMITIES (BOWING OR BENDING FRACTURES) Plastic deformities, also referred to as bowing or bending fractures, are almost exclusively limited to the forearm and lower leg long bones. The classic clinical hallmark is pain out of proportion to physical exami nation findings, and in the forearm, pain is maximal on pronation/ FIGURE 141-6. Radiograph of a Salter-Harris type IV fracture of distal tibia with a Salter I fracture of the fibula. [Photo used with permission of Karen Black, BC Children’s Hospital, Vancouver.] FIGURE 141-7. Torus fractures of the distal radius and ulna. [Figures used with permission of Karen Black, BC Children’s Hospital, Vancouver.] FIGURE 141-8. Anteroposterior and lateral radiographs demonstrating greenstick fractures of the distal radius and ulna in a child. [Reproduced with permission from Sherman SC: Simon’s Emergency Orthopedics, 7th ed. © 2015, McGraw-Hill, Inc., New York. Fig 13-15.] Tintinalli_Sec12_p0669-0996.indd 907 8/2/19 7:56 PM

er.] FIGURE 141-8. Anteroposterior and lateral radiographs demonstrating greenstick fractures of the distal radius and ulna in a child. [Reproduced with permission from Sherman SC: Simon’s Emergency Orthopedics, 7th ed. © 2015, McGraw-Hill, Inc., New York. Fig 13-15.] Tintinalli_Sec12_p0669-0996.indd 907 8/2/19 7:56 PM 908 SECTION 12: Pediatrics FIGURE 141-9. A. Injured right forearm demonstrating mild plastic deformation of the forearm. B. Lateral view of uninjured left forearm. [Reproduced with permission from Hospital for Sick Children 2018, Toronto, Canada.] FIGURE 141-10. Nondisplaced clavicle fracture in an infant ( arrow). supination. The cortex of the diaphysis of the long bone is deformed, but the periosteum along the entire diaphysis is preserved. Moderate-severe plastic deformity is usually obvious clinically, which should guide the inexperienced clinician who may think that in the absence of an obvious fracture the radiograph appearances are normal. Proper interpretation of the radiographs requires an awareness of the normal shape of the long bones involved because fracture lines and disruptions in the periosteum are absent ( Figure 141-9). Comparison films of the uninvolved extremity are helpful for mild cases of a bowing injury but typically not necessary for moderate or severe cases of plastic deformation. These fractures can occur in isolation of other fractures but can also be noted in combination with a dislocation or complete fracture of the other bone of the forearm or lower leg.  FRACTURES FROM CHILD ABUSE In general, any fracture in a nonmobile child should be considered suspicious for abuse. See Chapter 150, “Child Abuse and Neglect, ” for a complete discussion of child abuse.  UPPER EXTREMITY INJURIES CLAVICLE FRACTURES Clavicle fractures occur during two distinct time frames: the newborn period and childhood. Fractures of the clavicle in the newborn usually result from birth injury (Figure 141-10). Risk factors include high birth weight and shoulder dystocia. The infant may demonstrate upper extremity palsy secondary to a brachial plexus injury or may have “pseudoparalysis” of the extremity secondary to pain. Although many clavicle fractures are detected at birth, the diagnosis may be delayed, especially if the fracture is nondisplaced. An ED visit may be made when the newborn is not moving one arm during the first week of life, or when a parent notices a small “lump” or callus at the clavicle during the first 2 to 3 weeks of life. Clavicle fractures in the newborn do not need specific treatment. Pain control and careful handling of the baby are usually all that are required. Clavicle fractures outside of the newborn period usually result from accidental injury in a mobile child. The most common mechanism of injury is either a fall onto an outstretched hand or onto the lateral side of the shoulder. The clavicle may fracture in three general sites: the diaphysis, medial end, or lateral end.  FRACTURES OF THE MIDDLE THIRD OF THE CLAVICLE Fractures of the diaphysis usually occur in the middle third of the clavicle and are the most common of all clavicle fractures. Most of these injuries can be treated with analgesics, support of the injury with a Tintinalli_Sec12_p0669-0996.indd 908 8/2/19 7:56 PM

ral end.  FRACTURES OF THE MIDDLE THIRD OF THE CLAVICLE Fractures of the diaphysis usually occur in the middle third of the clavicle and are the most common of all clavicle fractures. Most of these injuries can be treated with analgesics, support of the injury with a Tintinalli_Sec12_p0669-0996.indd 908 8/2/19 7:56 PM CHAPTER 141: Pediatric Orthopedic Emergencies 909 during the interpretation of pediatric elbow radiographs. Assuming a proper lateral view of the elbow, the first line is the anterior humeral line. A line is drawn from the anterior humerus to the area distal to the capitellum. This line must bisect the middle third of the capitellum. If it is does not, consider an extension-type displaced supracondylar frac ture, displaced lateral condyle fractures or, rarely, a transphyseal fracture (Figure 141-11). The other line is drawn on the lateral view and is the radiocapitellar line, which runs through the middle-third of the radius and bisects the middle of the capitellum (Figure 141-11). If not, consider lateral condyle fracture, radial neck fracture, Monteggia fracture, or elbow dislocation. 4,5 Lateral radiographs are also used to evaluate for subtle effusions when an occult fracture is suspected. An anterior fat pad may be normal and appears as a small drop of oil hugging the distal anterior humerus. An anterior fat pad that seems to protrude like a sail from the distal humerus may be pathologic (“sail sign”), but when significant for an associated fracture, this finding typically occurs in association with a visible bony fracture or posterior fat pad (Figure 141-12). This is unlike the posterior fat pad that is evidence of a hemarthorsis from an intraarticular injury and is always considered pathologic even in the absence of a visible bony fracture (Figure 141-12).  ELBOW OSSIFICATION CENTERS It is important to identify the ossification centers around the elbow to avoid confusion with fracture. There are six ossification centers appearing at varying ages in the pediatric elbow. The mnemonic used over the years is CRITOE (capitellum, radial head, internal [medial] epicondyle, trochlea, olecranon, external [lateral] epicondyle). All of the ossification centers may be seen on the anteroposterior view of the elbow in the appropriately aged child, although the olecranon may be difficult to identify. On the lateral view, all are seen but the trochlea and external (lateral) epicondyle (CRIO). FIGURE 141-11. Anterior humeral and radiocapitellar lines. Anterior humeral line is drawn along the anterior cortex of the humeral shaft normally intersects the middle third of the capitellum. The radiocapitellar line is drawn along the long axis of the radial shaft should intersect the middle of the capitellum on each view. [Reproduced with permission from Hospital for Sick Children 2018, Toronto, Canada.] broad arm sling for 3 to 4 weeks, and follow-up with the primary care physician.1 Urgent orthopedic consultation is indicated when a child is >12 years of age, the fracture is ≥100% displaced and/or shortened ≥2 cm, or there is skin tenting, neurovascular compromise, and/or fracture through a pathologic lesion. Complete healing and remodeling can take more than 1 year, and a small callus will become palpable in most cases if the fracture was displaced.  FRACTURES OF THE MEDIAL CLAVICLE Fractures at the medial end of the clavicle are uncommon. Given the strong ligamentous attachment of the clavicle to the sternum, injuries to this area are usually epiphyseal disruptions. Orthopedic consultation is recommended for these injuries.  FRACTURES OF THE DISTAL CLAVICLE Fractures of the distal end of the clavicle are also uncommon in children and again more likely to be epiphyseal disruptions.

attachment of the clavicle to the sternum, injuries to this area are usually epiphyseal disruptions. Orthopedic consultation is recommended for these injuries.  FRACTURES OF THE DISTAL CLAVICLE Fractures of the distal end of the clavicle are also uncommon in children and again more likely to be epiphyseal disruptions. Minimally displaced distal clavicle fractures only need immobilization with a sling or equivalent. Surgical reduction may be needed for more displaced fractures. FRACTURES OF THE HUMERUS Fractures of the humerus are divided into three groups: fractures of the proximal humerus, fractures of the humeral diaphysis, and fractures of the condyles and supracondylar area. Supracondylar and condylar fractures are discussed as part of “The Pediatric Elbow” section below.  FRACTURES OF THE PROXIMAL HUMERUS Fractures of the proximal humerus may occur at the physis or the proximal humeral metaphysis, and they have an extraordinary ability to repair themselves. Proximal humeral physeal fractures occur more commonly in adolescence because this area becomes relatively weak during this time due to rapid growth. Fractures of the proximal humeral metaphysis are more common in preadolescents. Treatment depends on the age of the child and degree of displacement and/or angulation. In general, children ≤10 to 12 years of age with a proximal humeral fracture that is displaced ≤50% and <60 degrees angulated can be treated in a broad arm sling for 4 weeks and can be followed as an outpatient in an orthopedics clinic within a week. If the child is >10 to 12 years old with >50% displacement or >30 degrees of angulation, if there is a pathologic fracture, or if there is neurovascular compromise, then urgent referral to an orthopedic surgeon is indicated.  FRACTURES OF THE HUMERAL DIAPHYSIS Fractures of the humeral diaphysis are uncommon in children. Direct trauma can cause a transverse fracture, and violent rotation can cause a spiral fracture. Spiral/oblique fractures of the humeral diaphysis in infants and toddlers have been strongly linked to child abuse. 2 Rarely, the fracture fragment may injure the radial nerve as it runs in the radial groove. Thus, assess radial nerve function on initial examination and following any splinting (wrist extensors and supinators, sensation of dorsoradial hand, thumb, and second digits). Potential for healing is good, and treatment is usually immobilization in a long arm plaster splint and orthopedic follow-up. Closed reduction (or even open reduction and internal fixation) by orthopedics may be required for displaced fractures in the teenager. THE PEDIATRIC ELBOW Compared with other fractures, elbow fractures in children are com monly missed in the ED.3 The radiologic diagnosis of elbow fractures is challenging because of the large cartilaginous component of the elbow.  ELBOW RADIOGRAPHS True lateral and anteroposterior radiographs of the elbow are essential to diagnose fractures. There are two lines that should be routinely drawn Tintinalli_Sec12_p0669-0996.indd 909 8/2/19 7:56 PM

diagnosis of elbow fractures is challenging because of the large cartilaginous component of the elbow.  ELBOW RADIOGRAPHS True lateral and anteroposterior radiographs of the elbow are essential to diagnose fractures. There are two lines that should be routinely drawn Tintinalli_Sec12_p0669-0996.indd 909 8/2/19 7:56 PM 910 SECTION 12: Pediatrics FIGURE 141-12. Lateral elbow radiograph demonstrating anterior ( arrow) and posterior (arrow) fat pad sign. [Reproduced with permission from Hospital for Sick Children 2018, Toronto, Canada.]  SUPRACONDYLAR FRACTURES Supracondylar fractures are the most common elbow fractures in chil dren. The majority of supracondylar fractures occur in children from 3 to 10 years of age, with the peak incidence occurring between ages 5 and 7 years old. The extension type is by far the most common, accounting for 90% to 98% of cases ( Figure 141-11). An extension-type supra condylar fracture is caused by a fall on an outstretched hand with the elbow hyperextended. A flexion-type fracture results from falling on a flexed elbow and is rare. The complications of a supracondylar fracture, although uncommon, range from transient neurapraxia to Volkmann’s ischemic contracture, with the most common being injury to the ante rior interosseous nerve resulting in the “pointing finger sign. ” Classification of Supracondylar Fractures Classification of supra condylar fractures is based on the extent of fracture fragment displace ment. Type I fractures are displaced ≤2 mm and may have a posterior fat pad sign as the only radiographic finding (Figure 141-12). Radiologically occult fractures can often be confirmed on radiographs performed 2 to 4 weeks after the injury with the presence of a periosteal reaction of the humerus. Type II fractures are angulated to varying degrees, but the posterior cortex of the humerus is intact (Figure 141-13). Type III fractures are completely displaced with no cortical contact (Figure 141-14). The distal fragment may be posteromedially (type IIIa) rotated and, as such, can impinge against the radial nerve or be posterolaterally (type IIIb) rotated. In posterolaterally displaced fractures, the brachial artery and median nerve are at risk for injury, and compartment syndrome can develop. 6,7 If compartment syndrome is suspected (see Chapter 278, “Compartment Syndromes”), emergency orthopedic consultation is needed. Traction and reduction are indicated if the hand is cool, pale, and pulseless. The simple absence of a pulse in an otherwise viable hand is a contraindication to manipulation in the ED. Treatment The level of displacement and the prereduction physical examination dictate treatment of pediatric supracondylar fractures. Type I supracondylar fractures are inherently stable. The goal of therapy is pain control and immobilization with a long-arm posterior splint with the elbow at 90 degrees and the forearm in pronation or neutral rotation for 3 weeks. Arrange orthopedic follow-up within 2 to 7 days. While collar and cuff immobilization is used in some centers, it does not offer as good pain management as splinting. 8,9 Type II and III fractures need urgent orthopedic consultation in the ED for definitive management that typically includes operative pinning.10 Keep these patients fasting in anticipation of surgical intervention.  LATERAL CONDYLE FRACTURES Lateral condyle fractures occur when there is varus stress on an extended elbow with the forearm in supination. Swelling and tenderness are usu ally limited to the lateral elbow, and neurovascular injury is uncommon. Diagnosis can be made with standard anteroposterior and lateral views, but obtain an oblique view if clinical suspicion is high. Fractures can be Salter-Harris type II (most common) or IV .

he forearm in supination. Swelling and tenderness are usu ally limited to the lateral elbow, and neurovascular injury is uncommon. Diagnosis can be made with standard anteroposterior and lateral views, but obtain an oblique view if clinical suspicion is high. Fractures can be Salter-Harris type II (most common) or IV . Treatment is based on amount of displacement and articular congruence, and if this fracture is suspected, oblique views are recommended to determine maximal displacement. Type I lateral condylar fractures are defined by ≤2 mm displacement, and the child’s elbow injury can be treated in a long-arm backslab with the elbow flexed at 90 degrees and a broad arm sling ( Figure 141-15). Type II lateral condylar fractures occur when there is >2 mm displacement with congruity of the articular surface, while type III fractures occur with >2 mm displacement and without congruity of the articular surface. Type II and III lateral condylar fractures require urgent orthopedic consultation since these fractures often require open reduction and internal fixation. Nonunion, malunion, osteonecrosis, cubitus valgus, and tardy ulnar nerve palsy are well-described complications. Displacement can occur even within a cast or splint due to the pull of the forearm extensor tendons.  MEDIAL EPICONDYLE FRACTURES Fractures of the medial epicondyle tend to occur in older children, between the ages of 10 and 14 years old. They are not true Salter-Harris injuries because the apophysis rather than the physis is involved. Simple fractures of the medial epicondyle are extra-articular injuries with lim ited soft tissue involvement, but nearly half of injuries are associated with elbow dislocation; in such injuries, the epicondyle can become entrapped in the joint. 11,12 Fractures are classified by the amount of displacement and associated extremity injuries ( Figure 141-16). Typically, if there is <5 mm of displacement, these fractures can be managed in a long-arm backslab at 90 degrees of elbow flexion for 3 weeks and follow-up in orthopedics. The presence of >5 mm of displacement is an indication for urgent orthopedic consultation. It is important to dis tinguish a medial epicondyle fracture from a medial condyle fracture. Medial condyle fractures are intra-articular and require urgent review by an orthopedic surgeon.  MONTEGGIA FRACTURE DISLOCATION A Monteggia fracture-dislocation refers to the dislocation of the radial head (proximal radioulnar joint) with fracture of the ulna. This type of injury is the most commonly missed serious fracture of the elbow, and delayed or missed diagnosis is not infrequent. A good general rule is that if there an ulnar fracture, always look for an associated radius injury. Reduction is always required for these injuries. The Bado classification system identifies four types of Monteggia fractures. About 70% are type I, which occur when there is anterior dislocation of the radial head with fracture of the ulna shaft (Figure 141-17). Type II fractures represent about 5% and occur when there is posterior dislocation of the radial head and an ulnar fracture. About 25% are type III, whereby there is lateral dislocation of the radial head and an ulnar fracture. Finally, type IV , which is very rare, demonstrates anterior dislocation of the radial head and diaphyseal fractures of both the radius and ulna.  OLECRANON FRACTURES Olecranon fractures generally result from a fall on the elbow and are best seen on the lateral view (Figure 141-18). Orthopedic consultation is best to guide treatment. If the fracture is displaced ≤5 mm, it should be immobilized in the most stable position, usually 90 degrees of elbow flexion, for 3 to 6 weeks. Open reduction and internal fixation are indicated for unstable fractures.

e best seen on the lateral view (Figure 141-18). Orthopedic consultation is best to guide treatment. If the fracture is displaced ≤5 mm, it should be immobilized in the most stable position, usually 90 degrees of elbow flexion, for 3 to 6 weeks. Open reduction and internal fixation are indicated for unstable fractures. Olecranon fractures occur in association with fractures of the radial head and neck. A “simple” olecranon fracture may be part of a Monteggia lesion, so radial head position should be evaluated carefully. Tintinalli_Sec12_p0669-0996.indd 910 8/2/19 7:56 PM

e best seen on the lateral view (Figure 141-18). Orthopedic consultation is best to guide treatment. If the fracture is displaced ≤5 mm, it should be immobilized in the most stable position, usually 90 degrees of elbow flexion, for 3 to 6 weeks. Open reduction and internal fixation are indicated for unstable fractures. Olecranon fractures occur in association with fractures of the radial head and neck. A “simple” olecranon fracture may be part of a Monteggia lesion, so radial head position should be evaluated carefully. Tintinalli_Sec12_p0669-0996.indd 910 8/2/19 7:56 PM CHAPTER 141: Pediatric Orthopedic Emergencies 911 FIGURE 141-13. A. Clinical picture of a type II supracondylar fracture with marked soft tissue swelling in a child with a history of falling on an outstretched arm. B and C. Anteroposterior (AP) and lateral views of the elbow, demonstrating a supracondylar fracture with medial opening seen on the AP view and posterior displacement of the distal fragment identified on the lateral view. [A: Reproduced with permission from Shah BR, Lucchesi M, Amodio J, Silverberg M: Atlas of Pediatric Emergency Medicine,  2nd ed. © 2013, McGraw-Hill,  Inc., New York. Fig. 19-33A. B and C: Image used with permission of Karen Black, BC Children’s Hospital, Vancouver.]  RADIAL HEAD AND NECK FRACTURES Fractures of the radial head and neck are uncommon in children (Figures 141-19 and 141-20). The radial neck is fractured more frequently than the radial head, and most radial neck fractures occur through the metaphysis. The most common mechanism is a fall. Obtain orthopedic consultation to guide treatment. Reduction is often necessary when angulation is >35 degrees or displacement is >60%.  ELBOW DISLOCATION Elbow dislocations occur most frequently in males (70%), usually from a fall on the outstretched hand. The most common type of dislo cation is posterior, usually accompanied by some lateral displacement (Figure 141-21). Carefully examine the radiographs for associated fractures, particularly of the medial and lateral epicondyle and radial neck. Neurologic injury is associated with approximately 10% of elbow dislocations. Ulnar neuropathy is the most common and is usually associated with medial epicondyle entrapment. Median nerve injury may be caused by entrapment of the nerve inside the joint, behind the medial epicondyle, or in an epicondyle fracture. Radial nerve and arterial injury are both rare. Consult orthopedics emergently if neu rovascular injury is suspected (see Chapter 270, “Elbow and Forearm Injuries”). After reduction and review of postreduction radiographs, immobilize the reduced elbow in a posterior mold and refer for ortho pedic follow-up within 1 week. The major long-term complication is elbow stiffness.  SUBLUXATION OF RADIAL HEAD (NURSEMAID’S ELBOW) Subluxation of the radial head, otherwise known as a “pulled elbow” or “nursemaid’s elbow” is a common injury in young children. It can occur any time from birth to 6 years of age but commonly occurs from Tintinalli_Sec12_p0669-0996.indd 911 8/2/19 7:56 PM

bow stiffness.  SUBLUXATION OF RADIAL HEAD (NURSEMAID’S ELBOW) Subluxation of the radial head, otherwise known as a “pulled elbow” or “nursemaid’s elbow” is a common injury in young children. It can occur any time from birth to 6 years of age but commonly occurs from Tintinalli_Sec12_p0669-0996.indd 911 8/2/19 7:56 PM 912 SECTION 12: Pediatrics FIGURE 141-14. Type III displaced supracondylar fracture. The distal fragment is displaced posteriorly, proximally, and medially. [Reproduced with permission from Hospital for Sick Children 2018, Toronto, Canada.] FIGURE 141-15. Lateral condyle fracture (arrow) can be subtle in some views but displaces easily in the first week if not fixed operatively. [Reproduced with permission from Hospital for Sick Children 2018, Toronto, Canada.] 1 to 4 years of age. 14 It often results from a sudden pull on the arm, usually by an adult or taller person, but can also result from a fall or twist. The force pulls the radius through the annular ligament, resulting in subluxation (partial dislocation) of the radial head. Specifically, the annular ligament slips forward with traction and becomes entrapped between the radial head and the capitellum of the humerus. The child experiences sudden acute pain and loss of function of the affected arm. On examination, the child holds the involved arm in slight flexion and Tintinalli_Sec12_p0669-0996.indd 912 8/2/19 7:56 PM

gament slips forward with traction and becomes entrapped between the radial head and the capitellum of the humerus. The child experiences sudden acute pain and loss of function of the affected arm. On examination, the child holds the involved arm in slight flexion and Tintinalli_Sec12_p0669-0996.indd 912 8/2/19 7:56 PM CHAPTER 141: Pediatric Orthopedic Emergencies 913 FIGURE 141-16. Medial epicondyle avulsion. Note a flake of the medial condyle has fractured off as well. [Photo used with permission of Karen Black, BC Children’s Hospital, Vancouver.] FIGURE 141-17. Anteroposterior and lateral radiographs demonstrating a Monteggia fracture–ulnar fracture ( arrow) associated with radial head dislocation ( arrow). [Reproduced with permission from Hospital for Sick Children 2018, Toronto, Canada.] pronation, and there is no focal swelling or tenderness. However, there is significant tenderness elicited with pronation/supination of the fore arm. This is a clinical diagnosis and should not be confused with other radial head pathology (radial head/neck fractures) or bowing fractures that can also illicit tenderness with pronation/supination. Distinguish ing features between these entities in favor of a pulled elbow include lack of focal symptoms/signs, younger age, and relatively benign mechanisms. US may help exclude other injuries such as supracondylar fracture but can miss radial head fracture (See Video: Pediatric Elbow: Ultrasound Evaluation). There are two favored techniques to reduce a pulled elbow. The first is called the supination-flexion method. In this FIGURE 141-18. Anteroposterior and lateral radiographs demonstrating an olecranon fracture ( arrow). [Reproduced with permission from Hospital for Sick Children 2018, Toronto, Canada.] technique, grasp the humeral epicondyles with your thumb over the radial head, and with the other hand, quickly provide supination of the forearm and flex the elbow. An alternative method is called hyper pronation. Hold the child’s hand as if you are shaking hands, hold the Tintinalli_Sec12_p0669-0996.indd 913 8/2/19 7:56 PM

que, grasp the humeral epicondyles with your thumb over the radial head, and with the other hand, quickly provide supination of the forearm and flex the elbow. An alternative method is called hyper pronation. Hold the child’s hand as if you are shaking hands, hold the Tintinalli_Sec12_p0669-0996.indd 913 8/2/19 7:56 PM 914 SECTION 12: Pediatrics FIGURE 141-20. Anteroposterior radiograph illustrating radial neck fracture ( arrow). [Reproduced with permission from Hospital for Sick Children 2018, Toronto, Canada.] FIGURE 141-19. Lateral radiograph illustrating radial head fracture ( arrow). [Photo used with permission of Wake Medical Center, Raleigh, NC.] epicondyles with your other hand, extend the forearm, and pronate quickly. If one method is not successful, you can try the alternative method. A meta-analysis published in 2017 concluded that hyperpro nation was more effective in terms of success rate and seems less painful compared with the supination-flexion maneuver. 15 If successful, pain resolves after reduction and normal arm movement is quickly regained (See Video: Nursemaid Elbow). FOREARM INJURIES The vast majority of shaft fractures involve the distal third of the forearm in the metaphyseal area of the bone. Clinically, there is typically point tenderness and swelling, and occasionally, there is deformity. Clinical assessment should include the forearm and the joints above and below the primary injury to assess for the presence of associated fractures or dislocations at those joints. Radiograph assessment above and below the forearm is also indicated if the clinical examination of these areas is limited. FIGURE 141-21. Radiograph demonstrating elbow dislocation with displacement of both radius and ulna. [Reproduced with permission from Hospital for Sick Children 2018, Toronto, Canada.] Tintinalli_Sec12_p0669-0996.indd 914 8/2/19 7:56 PM

he forearm is also indicated if the clinical examination of these areas is limited. FIGURE 141-21. Radiograph demonstrating elbow dislocation with displacement of both radius and ulna. [Reproduced with permission from Hospital for Sick Children 2018, Toronto, Canada.] Tintinalli_Sec12_p0669-0996.indd 914 8/2/19 7:56 PM CHAPTER 141: Pediatric Orthopedic Emergencies 915  RADIUS AND ULNA DIAPHYSEAL FRACTURES Injuries of the shaft can remain unstable despite attempts at closed reduction and occasionally require open fixation. Proximal third shaft fractures are relatively uncommon. In skeletally immature children less than 10 years of age, angulation <10 degrees often does not require anatomic reduction. Bowing deformities can be difficult to diagnose and are often missed, and radiologic comparison with the uninjured side may be necessary in mild cases (Figure 141-9). Failure to correct bowing (which tends to be along the whole bone) may lead to permanent deformity and disability. While minimally angulated bowing fractures can be managed in a splint or cast and follow-up with an orthopedic surgeon, more advanced bowing fractures may require completion of the break to establish proper realignment. Prompt orthopedic consultation is required for any plastic deformities. In general, proper reduction and realignment are recom mended for any angulation ≥20 degrees in children less than 10 years of age or ≥15 degrees in children greater than 10 years of age. Consultation with orthopedics in the ED is advised to guide management for when a bowing injury is suspected. Isolated ulnar fractures are rare and are caused by a direct blow. If caused by an indirect force, typically, there is an associated fracture or dislocation of the radius. As per above, the combination of an ulnar fracture with a dislocation of the radial head is called Monteggia fracture (Figure 141-17). Galeazzi fracture is a radial shaft fracture with an associated dislocation of the distal radioulnar joint ( Figure 141-22). Although this injury is uncommon, immediate orthopedic consultation is warranted.  RADIUS AND ULNA METAPHYSEAL GREENSTICK OR COMPLETE FRACTURES Y ounger children and more distal injuries have a greater capacity for remodeling. In general, in girls age <10 years and boys age <12 years with fractures that are ≤15 degrees angulated in the sagittal and ≤5 mm displaced in the frontal plane do not need reduction and can be managed in a short-arm circumferential cast or splint for 4 to 6 weeks. 16 Follow-up with an orthopedic surgeon is still recommended since these fractures can be unstable and can displace further in follow-up regardless of whether they are managed in a cast or a splint. 17 For greater degrees of angulation, consult orthopedic surgery to determine the need for urgent reduction.  RADIUS AND ULNA METAPHYSEAL TORUS FRACTURES Torus or buckle-type fractures (Figure 141-7) of the distal forearm are the most common pediatric fracture. There is point tenderness over the distal radius and/or ulna, occasionally with associated localized swelling. These fractures are best treated by splinting in a position of function with follow-up with the primary care physician within 1 to 3 weeks. 18,19 Orthopedic surgery referral should be reserved for cases that are not healing as expected. Implementing this pathway is completely dependent on the emergency physician getting the correct radiologic diagnosis. Distal radius buckle fractures can be radiologically subtle and therefore can be missed without careful review of both the antero posterior and lateral radiograph views. In contrast, about 10% of cases thought to have a distal radius fracture actually have more advanced fractures such as distal radius greenstick or distal radius Salter-Harris type II fractures.

logically subtle and therefore can be missed without careful review of both the antero posterior and lateral radiograph views. In contrast, about 10% of cases thought to have a distal radius fracture actually have more advanced fractures such as distal radius greenstick or distal radius Salter-Harris type II fractures. 20 Although the latter fractures are also likely to heal well in a splint, they are less stable and typically require follow-up with an orthopedic surgeon.  DISTAL RADIUS PHYSEAL FRACTURES Salter-Harris fractures of the distal radial physis are assumed if there is point tenderness or swelling over the distal radius physis and there is no radiographic evidence of a visible bony fracture. These injuries are rarely associated with growth disturbances. Undisplaced or minimally displaced Salter-Harris I fractures should be immobilized with a below-elbow splint and followed in an orthopedic clinic within 1 week. Significantly displaced FIGURE 141-22. Galeazzi fracture. Note the widening of the distal radial ulnar joint space on the anteroposterior view ( A) and dislocation of the distal radius relative to the ulna on the lateral projection (B) (arrows). [Reproduced with permission from Simon RR, Sherman SC, Koenigsknecht SJ: Emergency Orthopedics: The Extremities, 5th ed, © 2007, McGraw-Hill, Inc., New York.] Tintinalli_Sec12_p0669-0996.indd 915 8/2/19 7:56 PM

r view ( A) and dislocation of the distal radius relative to the ulna on the lateral projection (B) (arrows). [Reproduced with permission from Simon RR, Sherman SC, Koenigsknecht SJ: Emergency Orthopedics: The Extremities, 5th ed, © 2007, McGraw-Hill, Inc., New York.] Tintinalli_Sec12_p0669-0996.indd 915 8/2/19 7:56 PM 916 SECTION 12: Pediatrics FIGURE 141-23. Anteroposterior, lateral, and oblique radiographs illustrating a minimally displaced Salter-Harris type II fracture ( arrows). [Reproduced with permission from Hospital for Sick Children 2018, Toronto, Canada.] Salter-Harris I fractures often require urgent closed reduction in the ED. Consult orthopedic surgery for guidance on when reduction is recom mended. Salter-Harris type II injuries (Figure 141-23) can be managed as per Salter-Harris I fractures of the distal radius. For Salter-Harris types III, IV , and V injuries, urgent orthopedic consultation is necessary. CARPAL BONE INJURIES Fractures of the carpal bones are quite rare in the skeletally immature child. However, these injuries increase in frequency in the skeletally mature adolescent population. Most are sports-related injuries. Frac ture patterns and presentation are similar to the adult, and scaphoid fractures are the most common type ( Figure 141-24), although rare in and of themselves. 21 For example, the scaphoid may be fractured in older adolescents with the typical mechanism being that of a fall on an outstretched hand. There is typically the classically expected snuffbox tenderness and pain with longitudinal compression of the thumb. However, unlike adults, nonunion is less common in children. 22 A high index of suspicion for this type of injury is required. Immobilize any suspected fracture of carpal bone in a thumb spica splint and arrange early ortho pedic follow-up, even in the absence of radiographic findings. Repeat plain radiographs, CT, or MRI may be used at follow-up for further assessment of the injury. PHALANGEAL FRACTURES The most common injury is that to the distal phalanx resulting from a crush injury, typically seen when the child catches his or her hand in a door. Immobilize a distal phalanx “tuft” fracture with a finger splint. If there is associated nail bed injury, the fracture is considered “open, ” and orthopedic or plastic surgery follow-up in 1 week or less must be arranged. The role of prophylactic antibiotics in open fractures of the distal tuft remains controversial, with no clear evidence of benefit. Fractures of the phalangeal shaft should be examined for displacement, rotational deformity, and tendon disruption. Significantly displaced or rotated fractures or those with tendon disruption need orthopedic/plastic surgery consultation for reduction and repair. FIGURE 141-24. Radiograph demonstrates a mildly displaced fracture of the distal aspect of the scaphoid bone involving the tubercle ( arrow). This is also minimally displaced with a tiny avulsion fragment. [Reproduced with permission from the Hospital for Sick Children, Toronto, Canada.] Tintinalli_Sec12_p0669-0996.indd 916 8/2/19 7:56 PM

graph demonstrates a mildly displaced fracture of the distal aspect of the scaphoid bone involving the tubercle ( arrow). This is also minimally displaced with a tiny avulsion fragment. [Reproduced with permission from the Hospital for Sick Children, Toronto, Canada.] Tintinalli_Sec12_p0669-0996.indd 916 8/2/19 7:56 PM CHAPTER 141: Pediatric Orthopedic Emergencies 917 FIGURE 141-25. Avulsion fracture of the anterior superior iliac spine of the pelvis. [Reproduced with permission from the Hospital for Sick Children, Toronto, Canada.] fracture the femoral shaft. The exception is in young healthy ambulatory children from 1 to 4 years of age, when femur fractures can occur with low-velocity injury such as a short fall or twisting or stumbling injury. Nevertheless, it is important to consider child abuse in a child with a femur fracture who is not yet walking. 26 Pediatric femur fractures occur more commonly in boys and seem to follow a bimodal distribution with peaks during late toddler age and mid-teenage years. The most common mechanisms of injury are falls, pedestrian versus automobile incidents, motor vehicle collisions, and sports-related injuries. The clinical findings of a femur fracture are usually obvious. There is typically tenderness and swelling over the fracture site. The child may hold the leg externally rotated and will likely refuse to bear weight. The leg may be shortened. Given the high degree of force needed to fracture the femur, perform a thorough evaluation for multisystem trauma. Hypotension is usually not related to an isolated femur fracture in a young child and should prompt a search for other injuries. 27 All femoral shaft fractures require immediate orthopedic consultation. Treatment depends on the child’s age, size, degree of malalignment, and reliability of follow-up. SLIPPED CAPITAL FEMORAL EPIPHYSIS Slipped capital femoral epiphysis (also known as slipped upper femoral epiphysis) is a disorder of childhood characterized by slipping of the femoral epiphysis of the hip. Complications include avascular necrosis of the hip and premature closure of the physis. Slipped capital femoral epiphysis is the most common cause of hip disability in adolescents. Etiology is multifactorial, and any child may develop slipped capital femoral epiphysis during a growth spurt; however, many affected children are obese adolescents whose hips are exposed to repetitive minimal trauma, but some are tall, athletic children. Boys with slipped capital femoral epiphysis present at an average age of 14 to 16 years old. Girls typically present earlier, at approximately 11 to 13 years of age, with occurrence after menarche being rare. Hormonal and genetic factors also appear to play a role in the development of slipped capital femoral epiphysis. Atypical slipped capital femoral epiphysis occurs in children in whom obesity is not a risk factor and can be seen in children with juvenile chronic arthritis, certain human leukocyte antigen types, endocrinopathies, renal failure, and previous radiation or chemotherapy. The slippage may be chronic, acute, or acute-on-chronic. Acute slipped upper femoral epiphyses are rare but quite dramatic. The child cannot bear weight, and surgery for reduction and fixation is done on an urgent basis. Acute worsening of mild chronic displacement may occur after minimal or no trauma. In cases of chronic slip, clini cally, the child may develop hip (groin) pain, or pain is referred to the thigh or, much more commonly, the knee. The pain may be vague and chronic in nature. If you watch the child walk, you will observe that the foot on the affected side has a much more external progression angle, and when you examine the hip, you will note that the hip flexes into obligate external rotation.

ferred to the thigh or, much more commonly, the knee. The pain may be vague and chronic in nature. If you watch the child walk, you will observe that the foot on the affected side has a much more external progression angle, and when you examine the hip, you will note that the hip flexes into obligate external rotation. Obtain bilateral hip radiographs in any adolescent with chronic pain in the groin, hip, thigh, or knee to evaluate for slipped capital femoral epiphysis because delay in diagnosis can lead to significant disability. Adequate radiographs include both anteroposterior and lateral hip radiographs (Lowenstein view). Both hips should be imaged given the high incidence of bilateral disease. The use of frog leg views is controversial given the potential for further epiphyseal displacement in this position. Radiographically, epiphyseal slippage may be detected by examining the anatomic rela tionship of the femoral neck to the femoral head (Figure 141-26 and Figure 141-27). Several techniques of measuring the presence or degree of slip have been suggested, but subtle cases can be challenging to find on radiographs. Therefore, obtain orthopedic consultation for any child with pain suspicious for slipped capital femoral epiphysis in the ED. Additional imaging with MRI to detect early slips may be recommended. Once the diagnosis is made, the goal of treatment is to prevent further slippage; management includes strict non–weight bearing and  LOWER EXTREMITY INJURIES PELVIC FRACTURES The immature, relatively cartilaginous pediatric pelvis is somewhat pliable. There are two broad categories of pelvic fractures: nonavulsive and avulsive. Nonavulsive pediatric pelvic fractures usually result from a tremendous force, and the most common mechanism for pelvic fractures is pedestrian versus motor vehicle collisions. 24 Assume multisystem injury in a child with a pelvic fracture, and transfer to a facility equipped to manage pediatric multiple trauma. In children, life-threatening hemorrhage usually results from injury to other body areas rather than from injury to the pelvic vessels. Avulsion-type injuries of the pelvis (Figure 141-25) result from sudden contraction of musculature attached to the pelvis and typically occur during athletic activities. These injuries are usually seen in the adolescent after secondary ossification centers develop and are unusual before 8 years of age. Clinically the child will complain of sudden pain and have point tenderness and possibly swelling over the fracture site (usually the anterior-superior iliac spine, but can occur at anterior-inferior iliac spine also). MRI or CT may be needed to confirm the diagnosis, but nearly all avulsion fractures can be managed conservatively with rest, limitation of activity until symptoms resolve, and orthopedic follow-up. HIP FRACTURES AND DISLOCATIONS Trauma can result in an epiphyseal disruption or a fracture of the head, neck, trochanteric, or subtrochanteric region of the femur. Proximal fractures involving the femoral head or neck have a high risk of com plications such as avascular necrosis and growth arrest. Treatment is almost always urgent operative repair. Traumatic dislocations of the hip are also rare in the pediatric popu lation and are best divided into those occurring in the older adolescent and those occurring in the skeletally immature child. Most hip disloca tions in adolescents are posterior and result from significant trauma. Dislocations in children <10 years old can occur with low-energy trauma. Treatment for pediatric hip dislocations is urgent closed reduction. Immediate orthopedic consultation is indicated, as any significant delay in reduction is associated with a higher incidence of complications including sciatic nerve injury.

auma. Dislocations in children <10 years old can occur with low-energy trauma. Treatment for pediatric hip dislocations is urgent closed reduction. Immediate orthopedic consultation is indicated, as any significant delay in reduction is associated with a higher incidence of complications including sciatic nerve injury. Pathologic fractures are possible through bone cysts or lesions. FRACTURES OF THE FEMORAL SHAFT The femur is the second bone to ossify in the fetus and the largest of the long bones in the body. The strength of the femur continues to increase in later childhood, and therefore, significant force is usually required to Tintinalli_Sec12_p0669-0996.indd 917 8/2/19 7:56 PM

ts or lesions. FRACTURES OF THE FEMORAL SHAFT The femur is the second bone to ossify in the fetus and the largest of the long bones in the body. The strength of the femur continues to increase in later childhood, and therefore, significant force is usually required to Tintinalli_Sec12_p0669-0996.indd 917 8/2/19 7:56 PM 918 SECTION 12: Pediatrics definitive operative management. Prophylactic pinning of the contra lateral hip, even if apparently unaffected, is also recommended by some authors.29 Prognosis depends on the degree of displacement; however, even in the best of cases, many patients are left with residual limited range of motion and an increased risk for the development of osteoarthritis. KNEE INJURIES Compared with the adult, ligamentous injuries to the pediatric knee are much less common than are fractures. Evaluation typically includes two radiograph views (anteroposterior and lateral) of the knee. The Ottawa Knee Rules (see Chapter 274, “Knee Injuries”) have been validated for children greater than 5 years of age and can help determine the need for radiographs.  FRACTURES OF THE DISTAL FEMORAL PHYSIS Fractures through the distal femoral physis are uncommon yet carry a significant complication rate. The popliteal artery lies close to the dis tal femoral metaphysis and may be injured along with the peroneal nerve. Growth arrest may also occur secondary to permanent physeal damage. Although Salter-Harris type I injuries may not be appreci ated on radiographs, any child suspected of having a significant injury should receive orthopedic follow-up. Any displaced distal femoral physeal disruption needs immediate orthopedic evaluation for reduc tion (Figure 141-28).  PATELLAR DISLOCATIONS Patellar injuries in children are usually dislocations. In fact, patellar dislocation is one of the most common causes of a traumatic hemarthrosis in children. The typical mechanism is one of pivoting the knee on a fixed lower leg. Often reduction has already occurred at the scene, although a history of the “knee popped out of place” can usually be obtained. If the patient remains dislocated at the emergency visit, the displaced patella usually sits laterally and the knee is held in flexion. Reduction need not be delayed for radiographs and is easily accomplished by gently extending the knee while another provider helps “lift” the patella into place. Although the patella does not actually need to be moved into place, the second provider can help prevent a traumatic reduction, resulting in additional fractures. Obtain radiographs after the reduction to assess for fractures, which are most typically seen at either the lateral femoral condyle or the medial margin of the patella. Provide a knee immobilizer and orthopedic follow-up within 1 to 2 weeks. Most patients improve with conservative management and rehabilitation; however, some chil dren are predisposed to chronic dislocations and may eventually need realignment of their extensor mechanism.  PATELLAR FRACTURE Fractures of the patella are uncommon in children and usually occur from direct blunt force. The “sleeve” fracture of the patella, in which the distal patellar “sleeve” is avulsed from the body of the patella, is a patellar fracture unique to children. The typical mechanism of an avulsion “sleeve” fracture is forceful contraction of the quadriceps against a fixed FIGURE 141-26. A. A line (Klein’s line) drawn along the lateral (superior) aspect of the femoral neck fails to transect the lateral quarter of the femoral head in slipped capital femoral epiphysis (Trethowan’s sign). B. The normal anatomic relationship is illustrated. FIGURE 141-27. Anteroposterior radiograph illustrating an early slipped capital femoral epiphysis requiring surgical management in right hip (arrow).

eck fails to transect the lateral quarter of the femoral head in slipped capital femoral epiphysis (Trethowan’s sign). B. The normal anatomic relationship is illustrated. FIGURE 141-27. Anteroposterior radiograph illustrating an early slipped capital femoral epiphysis requiring surgical management in right hip (arrow). Dotted line represents the Klein’s line on the unaffected side. Note that the epiphysis on the affected side would not be intersected by a similar line. [Photo used with permission of Karen Black, BC Children’s Hospital, Vancouver.] FIGURE 141-28. Distal femur Salter-Harris type II fracture. [Photo used with permission of Wake Medical Center, Raleigh, NC.] Tintinalli_Sec12_p0669-0996.indd 918 8/2/19 7:56 PM

the affected side would not be intersected by a similar line. [Photo used with permission of Karen Black, BC Children’s Hospital, Vancouver.] FIGURE 141-28. Distal femur Salter-Harris type II fracture. [Photo used with permission of Wake Medical Center, Raleigh, NC.] Tintinalli_Sec12_p0669-0996.indd 918 8/2/19 7:56 PM CHAPTER 141: Pediatric Orthopedic Emergencies 919 lower leg. Consultation with an orthopedist is advised to determine the appropriate treatment. PROXIMAL TIBIA FRACTURES  FRACTURES OF THE TIBIAL SPINE Mechanically speaking, an avulsion fracture of the tibial spine is the equivalent of an anterior cruciate ligament rupture in an adult. The anterior cruciate ligament inserts on the tibial eminence, also known as the anterior tibial spine, and this ligament and its insertion are much stronger than the epiphyseal bone in children. Nondisplaced fractures may be managed conservatively with immobilization in extension and orthopedic follow-up. However, any displaced fractures need reduction and immediate orthopedic consultation.  TIBIAL TUBEROSITY FRACTURES Tibial tuberosity fractures are typically avulsion type and occur most commonly from strong contraction of the quadriceps against a fixed leg. Such injuries are usually sports related. Tibial tuberosity fractures are classified as type I, II, or III, depending on the location of the fracture line. Type I injuries are characterized by a fracture through the small distal portion of the tibial tuberosity. Type II fractures occur after the coalescence of the secondary ossification centers of the tuberosity to the metaphysis. The fracture splits the epiphysis of the tuberosity from the epiphysis of the proximal tibia. Type III injuries involve a fracture into the joint and are at risk for compartment syndrome. Types I and II fractures are usually treated with immobilization. Displaced type II and type III injuries need reduction and fixation and require immediate orthopedic consultation.  PROXIMAL TIBIAL PHYSIS FRACTURES Fractures of the proximal tibial physis are relatively uncommon, and most are Salter-Harris type I. Vascular injury to the popliteal artery is a concern, and documentation of intact pulses is important.  PROXIMAL TIBIAL METAPHYSIS FRACTURES There is a high risk of drift through healing and growth into a valgus deformity of the knee (Cozen’s phenomenon) with proximal tibial metaphyseal fractures, even with proper alignment and immobilization. Arrange orthopedic follow-up for these fractures. FRACTURES OF THE TIBIA AND FIBULA DIAPHYSES Fractures of the tibia and fibula at the shaft are common. If the frac ture is minimally displaced and there is no evidence of compartment syndrome, immobilize in a long leg posterior splint and arrange ortho pedic follow-up. However, if there is >10 degrees of angulation in any plane, orthopedic consultation and reduction are indicated. These are very painful injuries and may require admission for pain relief. The mechanism of injury and the nature of the injury need to be considered when assessing the risk of compartment syndrome. Where there is high-energy injury, if the limb was in highly metabolic state at the time of injury (e.g., taking part in sports), or if there is any element of crush, then there is a risk of compartment syndrome, and the patient should be admitted for observation.  TODDLER’S FRACTURE The toddler’s fracture is an isolated spiral fracture of the distal tibia in a toddler (i.e., once learning to walk). The typical mechanism is external rotation of the foot with the knee flexed. Parents report that the child is limping or refusing to bear weight for no evident reason or after seemingly insignificant trauma.

oddler’s fracture is an isolated spiral fracture of the distal tibia in a toddler (i.e., once learning to walk). The typical mechanism is external rotation of the foot with the knee flexed. Parents report that the child is limping or refusing to bear weight for no evident reason or after seemingly insignificant trauma. Clinically, there is usually pain with palpation and rotation of the distal tibia, although swelling may be minimal or absent, and occasionally there is no tenderness. Obtain radio graphs of the leg in the limping toddler, even in the absence of physical examination finding. Radiographically, a fracture line may be noticed at the distal third of the tibial shaft (Figure 141-29). At times, initial standard radiographs may be normal. Oblique views may show a fracture line when standard views are negative. If a toddler’s fracture is clinically suspected and initial radiographs are negative, splint immobilization and no immobilization are both management options with follow-up in 1 week for repeat radiographs. 31,32 If radiographs are negative and there is also the absence of a traumatic history, clinicians are encouraged to rule out other possible diagnoses that could lead to difficulty weight bearing in a young child. For radiologically evident fractures, there is currently a wide practice variation. Options include immobilization of the injured leg in a long leg splint, removable prefabricated device, or above-knee cast with adequate fixation. 33-35 The most commonly applied standard is a long-leg splint in the ED followed by an above- or below-knee cast with adequate fixation placed in an orthopedics clinic. ANKLE INJURIES Ankle injuries in children include both ligamentous disruptions as well as fractures. With the exception of the distal fibula, 36 ligamentous injuries are uncommon before physeal closure because of the generally stronger nature of ligaments when compared with open physes. Ankle sprains in older children with closed physes are graded and treated as they are in adults. Fractures of the pediatric ankle may involve the distal tibia, the fibula, or both. A thorough evaluation and appropriate treatment are extremely important because any articular surface disruption in this joint can result in long-term complications despite a seemingly benign initial presentation. The Low-Risk Ankle Rule has been validated exclusively in children >3 years of age and aims to reduce unnecessary radiography in children with ankle injuries (Figure 141-30). 37 In a multicenter impact analysis, implementation of this ankle rule reduced radiographs by 22% and demonstrated significant healthcare cost savings. 38,39 Once radiographs are considered necessary, standard views include anteroposterior, lat eral, and oblique views. Distal tibia fractures may be at higher risk of FIGURE 141-29. Anteroposterior radiograph illustrating toddler’s fracture of tibial shaft (arrow). [Photo used with permission of Wake Medical Center, Raleigh, NC.] Tintinalli_Sec12_p0669-0996.indd 919 8/2/19 7:56 PM

s include anteroposterior, lat eral, and oblique views. Distal tibia fractures may be at higher risk of FIGURE 141-29. Anteroposterior radiograph illustrating toddler’s fracture of tibial shaft (arrow). [Photo used with permission of Wake Medical Center, Raleigh, NC.] Tintinalli_Sec12_p0669-0996.indd 919 8/2/19 7:56 PM 920 SECTION 12: Pediatrics complications; thus, additional imaging techniques such as CT and MRI can be used to help define the extent of fracture involvement.  DISTAL FIBULA ANKLE FRACTURES Distal fibula ankle fractures are the most common lower extremity injury in children over 5 years of age. The key fractures to consider in this location are Salter-Harris I and II and fibular avulsion fractures. Children who present with lateral ankle injuries and no radiographic evidence of a fracture are commonly diagnosed with a distal fibular Salter-Harris I physeal fracture. However, in a recent study that included 135 skeletally immature children with this clinical scenario, MRI demonstrated that, in fact, only four (3%) of these children had Salter- Harris I fractures of the distal fibula, two of which were partial injuries, and all children had ligamentous injuries and/or bony contusions. Thus, radiograph-negative lateral ankle injuries in children are more appropriately diagnosed with ligamentous injuries and managed with a removable ankle brace and self-regulated return to activities. 40 Thus, routine orthopedic follow-up is not necessary for these cases and can be reserved for cases not recovering as expected. Salter-Harris type II and distal fibular avulsion fractures occur with an inversion injury. In general, when there is no significant displacement, these fractures may be managed by immobilization in a weight-bearing cast or commercial immobilizer, and orthopedic follow-up is usually not necessary. 40-42 In isolation, distal fibular Salter-Harris type III to V frac tures are very rare. If suspected, consult with orthopedics for management.  DISTAL TIBIA ANKLE FRACTURES Salter-Harris I and II fractures of the distal tibia are the most common fractures of the distal tibia. They can be managed with immobilization and follow-up in an orthopedic clinic but may also require closed reduction in the ED if any displacement is present. Salter-Harris III fractures account for approximately 25% of distal tibia fractures and typically require open reduction of any displacement. Tillaux fracture is a Salter- Harris type III fracture of the anterolateral portion of the distal tibia (Figure 141-5). The location of Tillaux fracture is a result of the order in which the distal tibial physis closes. Physeal closure occurs centrally, then medially, and finally, laterally, making the anterolateral portion most vulnerable. Therefore, this type of fracture is typically seen in a child who is nearing skeletal maturity. Treatment is surgical reduction in most cases that demonstrate displacement, and thus, urgent orthopedic consultation is indicated. Salter-Harris IV fractures include the triplane fracture, which involves fractures in the sagittal, coronal, and transverse planes, resulting in multiple fracture fragments. CT scan is helpful in delineating the extent of the joint surface injury in both Salter-Harris type III and IV ankle fractures ( Figure 141-31). The management is –Tenderness + edema isolated to the distal fibula and/or adjacent lateral ligaments distal to the tibial anterior joint line Lateral view AP view A Distal tibia including growth plate B Distal fibula including growth plate C Lateral ligaments including anterior talofibular, calcaneofibular and posterior talofibular D Calcaneus C D FIGURE 141-30.

d to the distal fibula and/or adjacent lateral ligaments distal to the tibial anterior joint line Lateral view AP view A Distal tibia including growth plate B Distal fibula including growth plate C Lateral ligaments including anterior talofibular, calcaneofibular and posterior talofibular D Calcaneus C D FIGURE 141-30. If a child has tenderness and swelling isolated to the distal fibula or adjacent lateral ligaments distal to the anterior joint line, then radiography may not be necessary to exclude a clinically important ankle injury. AP = anteroposterior. [Reproduced with permission from Boutis K, Komar L, Jaramillo D, et al: Sensitivity of a clinical examination to predict need for radiography in children with ankle injuries: a prospective study. Lancet 358 (9299): 2118-2121, 2001.] FIGURE 141-31. A. Mortise view of the ankle demonstrating a Salter-Harris type IV fracture of the tibia known as the triplane fracture with an associated fibular shaft fracture. B. CT lateral projection showing the fracture lines through the metaphysis (coronal plane), physis (transverse plane), and epiphysis (sagittal plane). [Photos used with permission of Karen Black, BC Children’s Hospital, Vancouver.] Tintinalli_Sec12_p0669-0996.indd 920 8/2/19 7:57 PM

n associated fibular shaft fracture. B. CT lateral projection showing the fracture lines through the metaphysis (coronal plane), physis (transverse plane), and epiphysis (sagittal plane). [Photos used with permission of Karen Black, BC Children’s Hospital, Vancouver.] Tintinalli_Sec12_p0669-0996.indd 920 8/2/19 7:57 PM CHAPTER 141: Pediatric Orthopedic Emergencies 921 often urgent surgical reduction. Premature closure of growth plates is more common in Salter-Harris II to IV fractures, whereas it is relatively infrequent in Salter-Harris I and Tillaux fractures. FOOT AND TOE INJURIES In early childhood, the pliability and lack of ossification of the foot make fractures in this area rare. As ossification increases with age, fractures become more common, but significant injuries are still unusual. The foot is divided into the hindfoot (calcaneus and talus), the midfoot (navicular, cuboid, second and third cuneiforms), and the metatarsals and phalanges. Fractures of the mid- and hindfoot are rare; however, when they occur, they usually result from a fall. Recognition of frac tures in these areas may be difficult, and CT or MRI may be necessary to identify and define these fractures. Fractures of the metatarsals and phalanges are relatively common in children and typically result from a direct blow from a falling object. They typically heal without sequelae. Crush injury to the foot may cause vascular compromise and compart ment syndrome; these patients should be admitted for foot elevation and observation even if no fracture is detected. Most nondisplaced fractures of the metatarsals and phalanges can be managed by immobilization in a posterior short-leg splint and follow-up with an orthopedist. Significantly displaced fractures of the metatarsals and phalanges as well as those of the great toe that have intra-articular involvement may require fixation, although this can typically be done on an outpatient basis. Fractures of the base of the fifth metatarsal are common with inver sion injuries of the ankle as in adults. The evaluation of ankle injuries should therefore include radiographs of the foot when there is ten derness over the fifth metatarsal. The immature skeleton includes an ossification center lateral to the base of the fifth metatarsal to which the peroneus brevis tendon attaches. This ossification center may be confused with a fracture, although an avulsion fracture at this site can also occur and presents with point tenderness and displacement of the ossification center (Figure 141-32). Immobilization and orthopedic follow-up are recommended.  SELECTED NONTRAUMATIC MUSCULOSKELETAL DISORDERS OF CHILDHOOD ACUTE SEPTIC ARTHRITIS Septic arthritis occurs in all age groups, but especially in children <3 years of age. The reported incidence of septic arthritis varies from 2 to 5 per 100,000 per year in the general population to 28 to 38 per 100,000 per year in patients with rheumatoid arthritis. Although any joint can be infected and multiple joints can be involved, the hip and the knee account for nearly 80% of cases. Bacteria are the usual pathogens in acute skeletal and joint infec tions. Bacteria may access the joint hematogenously, by direct extension from adjacent osteomyelitis, or from inoculation, as in arthrocentesis or femoral venipuncture. Hematogenous spread is the most common. Although Staphylococcus aureus is still the most common pathogen in osteoarticular infections, infection with community-acquired meth icillin-resistant S. aureus and other multidrug-resistant organisms is increasing. In Europe, Kingella kingae (gram-negative coccobacilli) is reported to cause bone and joint infections, with only sporadic case reports of outbreaks in the United States.

osteoarticular infections, infection with community-acquired meth icillin-resistant S. aureus and other multidrug-resistant organisms is increasing. In Europe, Kingella kingae (gram-negative coccobacilli) is reported to cause bone and joint infections, with only sporadic case reports of outbreaks in the United States. 44 Widespread vaccination has decreased the prevalence of Haemophilus influenzae type B, reducing FIGURE 141-32. Fracture of the base of the fifth metatarsal. A. Jones fracture ( arrow). B. Avulsion fracture of the tuberosity. [Reproduced with permission from Sherman SC: Simon’s Emergency Orthopedics, 7th ed. © 2015, McGraw-Hill, Inc., New York. Fig 23-33A&B.] Tintinalli_Sec12_p0669-0996.indd 921 8/2/19 7:57 PM

ing FIGURE 141-32. Fracture of the base of the fifth metatarsal. A. Jones fracture ( arrow). B. Avulsion fracture of the tuberosity. [Reproduced with permission from Sherman SC: Simon’s Emergency Orthopedics, 7th ed. © 2015, McGraw-Hill, Inc., New York. Fig 23-33A&B.] Tintinalli_Sec12_p0669-0996.indd 921 8/2/19 7:57 PM 922 SECTION 12: Pediatrics TABLE 141-2 Differential Considerations for the Acutely Inflamed Pediatric Joint •   Reactive or toxic synovitis •   Trauma •   Septic arthritis •   Acute rheumatic fever •   Poststreptococcal reactive arthritis •   Gonococcal arthritis •   Lyme disease •   Sickle cell crisis •   Henoch-Schönlein purpura •   Legg-Calvé-Perthes disease •   Slipped capital femoral epiphysis •   Osteomyelitis •   Juvenile rheumatic arthritis •   Transient synovitis •   Hemophilia •   Osgood-Schlatter disease TABLE 141-1 Causes of Suppurative Arthritis in Children in Order of Decreasing Incidence Newborn (0–2 mo) Infant (2–36 mo) Child (>36 mo) Methicillin-sensitive Staphylococcus aureus (MSSA) MSSA MSSA Methicillin-resistant S. aureus (MRSA) MRSA MRSA Group B Streptococcus Streptococcus species Streptococcus species Gram-negative bacilli Gram-negative bacilli Gram-negative bacilli Neisseria gonorrhoeae Haemophilus influenzae N. gonorrhoeae H. influenzae Unknown or unidentified Candida albicans invasive disease. Common etiologic organisms also vary with the age of the child (Table 141-1). Even though septic infections of joints in children are uncommon, they are important because of their potential to cause permanent disability.  CLINICAL FEATURES AND DIAGNOSTIC IMAGING The earliest signs and symptoms of septic arthritis are subtle. Neonates do not characteristically appear ill and, in half of cases, do not have fever. Older infants, toddlers, and children usually have fever and localizing signs. Infants may have only pseudoparalysis (absence of spontaneous movement) of an extremity or apparent pain on movement of the affected extremity. The child with hip or knee septic arthritis will limp or not walk at all. The child maintains the infected hip in flexion, abduction, or internal rotation. On physical examination of the septic knee, the manifestations are those of any localized infection (i.e., erythema, swelling, tenderness, and pain); these signs are not easily detected in the hip. Older children will appear ill, often with high fever (40.0 to 40.5°C [104 to 105°F]), with apprehension and irritability. Children at special risk for septic infections of the bone and joint include those with underlying immune deficiency or systemic disease, including recent chickenpox, sickle cell anemia, rheumatoid arthritis, and inflammatory bowel disease. Maintain a high index of suspicion for septic arthritis in such children. Plain film radiographs are nondiagnostic early in the course of infec tion but should be obtained to help identify osteomyelitis, fracture, or another process in the differential diagnosis. Widening of the joint space with joint effusion and distention are late findings. Fat lines are displaced early in septic arthritis because of cap sular distention. Views of the contralateral side may be useful for com parison. Ultrasonography is useful to document the presence of a joint effusion and aids in needle aspiration. CT and MRI provide improved soft tissue resolution and can aid in the diagnosis. The differential diagnosis is listed in Table 141-2.  DIAGNOSIS If septic arthritis is suspected, obtain a CBC, blood cultures, erythrocyte sedimentation rate, C-reactive protein, and throat cultures; call ortho pedics; and keep the child fasted/nothing by mouth. Arthrocentesis provides definitive diagnosis and should not be delayed while awaiting laboratory studies (see Chapter 284, “Joints and Bursae”).

uspected, obtain a CBC, blood cultures, erythrocyte sedimentation rate, C-reactive protein, and throat cultures; call ortho pedics; and keep the child fasted/nothing by mouth. Arthrocentesis provides definitive diagnosis and should not be delayed while awaiting laboratory studies (see Chapter 284, “Joints and Bursae”). Administer empiric antibiotics immediately if septic arthritis is suspected and orthopedic care is not available within 24 hours. Patients at risk for septic arthritis usually have temperature >38.5°C (101.3°F), a C-reactive protein >20 milligrams/L (usually high), leukocytosis (>12,000 cells/mm 3), severe pain, tenderness on palpation, spasm, and refusal to walk. Obtain joint fluid and send fluid for cell count, Gram stain, glucose, and culture and polymerase chain reaction testing. 45 Isolation of an organism from the joint fluid does not occur in approximately one third of cases, but purulent fluid confirms the diagnosis when the clinical exam is suggestive. Fastidious or slow-growing organisms may not grow in culture. Likewise, the bacteriostatic effect of synovial fluid or prior empiric antibiotic therapy may decrease the sensitivity of joint aspirate cultures. When blood cultures are obtained, they are positive in less than half of cases, but they are the only source from which the causative agent is isolated in about 10%. Polymerase chain reaction studies of joint fluid improve organism detection. 45,46 Concurrent infections at other sites may be associated with septic arthritis, and culture of those sites may help define the pathogen (e.g., urine gram-negative bacilli; skin/wound S. aureus; urethra, cervix, rec tum, and pharynx Neisseria gonorrhoeae).  TREATMENT Treatment is prompt joint drainage and wash-out (open, in the oper ating room) followed immediately by IV antibiotic administration. If orthopedic care will be delayed, then IV antibiotics should be started. Table 141-3 lists possible choices for initial antibiotic therapy, includ ing empiric treatment. The prognosis depends on the length of time between symptom onset and treatment. A treatment delay of more than 4 days increases the likelihood of orthopedic complications, and infants have less favorable outcomes. TRANSIENT SYNOVITIS OF THE HIP Toxic or transient synovitis is a benign, self-limiting inflammatory process of the hip. It afflicts males more than females and is the most common cause of acute hip pain in children <10 years of age. The peak incidence is between ages 3 and 6 years old, but it is reported from 9 months of age to adolescence. It is eight times more frequent than septic arthritis of any joint. The cause is unknown, but it is most often believed to be a postviral illness sequela, but trauma, bacterial infec tion, and postvaccine or drug-mediated reactions have also been cited as possible causes. Arthralgia and arthritis are secondary to a transient inflammation and hypertrophy of the synovial membrane.  CLINICAL FEATURES Symptoms are characterized by an abrupt onset of unilateral hip pain, limp, and restricted hip motion (preferentially held in abduction and external rotation). The child may complain of pain in the anterome dial or anterolateral thigh and knee. Although children complain of discomfort with movement of the limb, it generally remains possible to put the hip through a full range of motion. This is in contrast to the septic hip in which pain and spasms are more severe and range of motion is decreased. The child is nontoxic appearing, and other signs of systemic illness are absent. There can be either no fever or a low-grade Tintinalli_Sec12_p0669-0996.indd 922 8/2/19 7:57 PM

hrough a full range of motion. This is in contrast to the septic hip in which pain and spasms are more severe and range of motion is decreased. The child is nontoxic appearing, and other signs of systemic illness are absent. There can be either no fever or a low-grade Tintinalli_Sec12_p0669-0996.indd 922 8/2/19 7:57 PM CHAPTER 141: Pediatric Orthopedic Emergencies 923 TABLE 141-3 Initial Antibiotic Therapy of Acute Suppurative Arthritis in Children Age Suspected Organism Antibiotics Newborn (0–2 mo) Staphylococcus aureus Vancomycin, 10 milligrams/kg every 6–8 h Clindamycin, 10 milligrams/kg every 6–8 h Group B Streptococcus Ampicillin, 50–100 milligrams/kg every 6 h and Cefotaxime, 50 milligrams/kg every 6–8 h Ceftriaxone, 50 milligrams/kg every 12 h Gram-negative bacilli Cefotaxime, 50 milligrams/kg every 8 h Neisseria gonorrhoeae Cefotaxime, 50 milligrams/kg every 8 h Unknown Vancomycin or clindamycin and cefotaxime or ceftriaxone (dosing as above) Infant (2–36 mo) S. aureus Vancomycin or clindamycin (dosing as above) Streptococcus species Clindamycin/cefotaxime/ceftriaxone (dosing as above) Gram-negative bacilli Cefotaxime or ceftriaxone (dosing as above) Haemophilus influenzae Cefotaxime or ceftriaxone (dosing as above) Unknown Vancomycin or clindamycin and cefotaxime or ceftriaxone Child (>36 mo)

or clindamycin (dosing as above) Streptococcus species Clindamycin/cefotaxime/ceftriaxone (dosing as above) Gram-negative bacilli Cefotaxime or ceftriaxone (dosing as above) Haemophilus influenzae Cefotaxime or ceftriaxone (dosing as above) Unknown Vancomycin or clindamycin and cefotaxime or ceftriaxone Child (>36 mo) S. aureus Vancomycin or clindamycin Streptococcus species Clindamycin/cefotaxime/ceftriaxone Gram-negative bacilli Cefotaxime or ceftriaxone N. gonorrhoeae Cefotaxime or ceftriaxone Unknown Vancomycin or clindamycin and cefotaxime or ceftriaxone Ceftriaxone should not be used in neonates <1 month of age. temperature elevation. The mean WBC count and erythrocyte sedimentation rate are significantly lower than in septic arthritis, but they cannot be used to distinguish between transient synovitis and septic arthritis in individual patients (see discussion of acute septic arthritis above). Radiographs of the hip may be normal or may demonstrate an effusion. There are no bone changes associated with transient synovitis. US is more sensitive than plain films at detecting joint effusions, although accuracy is decreased in patients <1 year of age. Reports of an effusion of the hip by US in toxic synovitis vary from 50% to 95%.  DIAGNOSIS This is primarily a clinical diagnosis that is supported by WBC, C-reactive protein, and erythrocyte sedimentation rate levels that are not significantly elevated. Further, hip radiographs are normal. US may demonstrate a small hip effusion. If the peripheral WBC count and erythrocyte sedimentation rate are substantially elevated and a hip effusion is noted on radiograph or US, perform a diagnostic arthrocentesis and obtain orthopedic consultation to exclude a septic joint. Send synovial fluid for Gram stain, aerobic and anaerobic cultures, and acid-fast bacilli with culture. Synovial fluid is sterile and clearly transudative with no organisms on Gram stain.  TREATMENT Treatment is with rest until the pain resolves, usually 3 to 7 days, fol lowed by limited activity for 1 to 2 weeks. NSAIDs are the first-line therapy for pain. There are no sequelae from transient synovitis. As long as the diagnosis is certain, reevaluation by the primary care physician can be arranged within 2 weeks. JUVENILE IDIOPATHIC ARTHRITIS Juvenile idiopathic arthritis is an umbrella term that has replaced the term juvenile rheumatoid arthritis. Juvenile idiopathic arthritis includes a heterogeneous group of arthritides of unknown cause that develop in children <16 years old. A detailed presentation of each type of arthritis is beyond the scope of this chapter. Systemic juvenile idiopathic arthritis is discussed in the following paragraphs. Systemic juvenile idiopathic arthritis is associated with high fevers and chills, characteristically with spikes to at least 39°C (102.2°F) for a minimum of 2 weeks. There is also an accompanying characteristic faint erythematous macular coalescing rash that can involve the trunk, palms, and soles. The arthritis is usually polyarticular. Associated findings are hepatosplenomegaly, lymphadenopathy, and pleuritis or pericardial effusion. Laboratory evaluation is not highly specific but can be sig nificant for anemia, leukocytosis, thrombocytosis, elevated acute-phase reactants (erythrocyte sedimentation rate and C-reactive protein), and elevated serum immunoglobulins. Arthrocentesis may be necessary to exclude acute septic arthritis, especially in oligoarticular disease. Early in the course, radiographs demonstrate only soft tissue swelling and, possibly, synovial effusions. Bone and cartilage destruction occurs later.

ate and C-reactive protein), and elevated serum immunoglobulins. Arthrocentesis may be necessary to exclude acute septic arthritis, especially in oligoarticular disease. Early in the course, radiographs demonstrate only soft tissue swelling and, possibly, synovial effusions. Bone and cartilage destruction occurs later. One of the most life-threatening complications is an entity called macrophage activating syndrome caused by macrophage and T-lymphocyte proliferation and is characterized by multiorgan system failure. Clinical findings can include high fever, purpura, spontaneous mucosal bleeding, altered mental status, and hepatosplenomegaly. Laboratory evaluation can reveal pancytopenia, liver dysfunction, disseminated intravascular coagulopathy, hyperferritinemia, hypertriglyceridemia, and low fibrinogen. Treatment may include symptomatic care in addi tion to pulse corticosteroids and cyclosporine A or a biologic. Hospital admission is needed to establish the diagnosis and to treat suspected acute suppurative arthritis while synovial fluid cultures are pending. A pediatric rheumatologist should direct management strat egies, including intra-articular glucocorticoid injections and use of methotrexate (current first-line agent) and other biologic or nonbiologic disease-modifying antirheumatic drugs. AVASCULAR NECROSIS AND APOPHYSITIS Legg-Calvé-Perthes disease is the most common example of avascular necrosis or osteochondrosis. Nevertheless, any primary or secondary ossification center can undergo changes consistent with necrosis and alteration of bone growth, with more common sites being the navicular (Koehler’s disease), second metatarsal (Freiberg’s disease), capitellum (Panner’s disease), and lunate (Kienbock’s disease), as well as the apophyses of the patella (Sinding-Larsen-Johanssen disease), tibia (Osgood- Schlatter disease), and calcaneus (Sever’s disease). LEGG-CALVÉ-PERTHES DISEASE Legg-Calvé-Perthes disease is a hip disorder that occurs in the femoral head that generally has an onset between the ages of 4 and 9 years old in 80% of patients, with a range of occurrence from 2 to 13 years and should be considered in the limping child in this age range. Males outnumber females by a ratio of 4:1, and it is bilateral in 10% of cases. Most children with the disorder are small for their age, with delayed skeletal maturation.  CLINICAL FEATURES The onset of disease is usually insidious. Mild hip pain and limp have been present for weeks to months before making the diagnosis. Initially, pain is mild to none and is often referred to the anteromedial thigh or Tintinalli_Sec12_p0669-0996.indd 923 8/2/19 7:57 PM

ith delayed skeletal maturation.  CLINICAL FEATURES The onset of disease is usually insidious. Mild hip pain and limp have been present for weeks to months before making the diagnosis. Initially, pain is mild to none and is often referred to the anteromedial thigh or Tintinalli_Sec12_p0669-0996.indd 923 8/2/19 7:57 PM 924 SECTION 12: Pediatrics knee. Physical findings include decreased hip abduction and internal rotation. Proximal thigh atrophy and, in advanced cases, limb shorten ing may also be noted. Radiographically, in the initial stage of the disease (1 to 3 months), the capital femoral epiphysis fails to grow because of the lack of blood supply. The hip radiograph demonstrates widening of the cartilage space of the affected hip and a small-size ossific nucleus of the femoral head (Figure 141-33). Next, a subchondral stress fracture line in the femoral head is evident (Caffey’s sign). As the disease progresses, new bone is deposited on avascular trabeculae. Subsequently, calcification of the more radiopaque necrotic marrow occurs, with resultant crushing of the avascular trabeculae in the dome of the epiphysis. Further distortion of the femoral head progresses (although this is not inevitable), along with subluxation and extrusion of the femoral head from the acetabulum. The diagnosis of Legg-Calvé-Perthes disease demands a high index of suspicion, because initial radiographs sometimes are normal. Bone scan and MRI can detect disease before plain film abnormalities are evident.  TREATMENT Once this condition is suspected, urgent orthopedic referral is recommended. OSGOOD-SCHLATTER DISEASE Osgood-Schlatter disease is an apophysitis of the tibial tubercle resulting from repeated normal stresses or overuse. These repetitive stresses imposed by the patellar tendon on its site of insertion result in a series of microavulsions of the ossification center and the underlying cartilage. Inflammation causes patellar tendonitis and the development of a remarkable prominence, induration, and tenderness of the tibial tuberosity. There is no avascular necrosis of the tibial tubercle. Children are usually between 10 and 15 years of age at time of onset; it more commonly occurs in running or jumping athletes. Boys are affected more often than girls, and most cases are bilateral, although symptoms are commonly asymmetric.  CLINICAL FEATURES Signs and symptoms of Osgood-Schlatter disease are chronic, inter mittent pain and tenderness over the anterior aspect of the knee and the tibial tuberosity. Pain is aggravated by activities such as running, kneeling, squatting, and climbing stairs; pain improves with rest. On examination, there is a prominence and soft tissue swelling over the tibial tubercle. The patellar tendon is tender and thick. The remainder of the knee examination usually is normal, and there is no knee effusion. Radiographs are not essential but are usually obtained. Radiographic findings of soft tissue swelling and irregularities of the tibial tubercle are nonspecific (Figure 141-34). The irregularity of the ossification of the tibial tubercle is normal in this age group. A lateral knee radiograph may show prominence of the tibial tuberosity, calcification in the tibial tubercle region, or separate ossicles from the anterior border of the tubercle.  TREATMENT The disease is self-limited, and most patients’ symptoms respond to rest and temporary avoidance of the offending activity. However, complete avoidance of activity or sports is not essential. Immobilization is actually contraindicated and can lead to rapid atrophy of the quadriceps muscle. Physical therapy and flexibility exercises to stretch and strengthen the quadriceps and hamstring muscles may help to alleviate stress on the tubercle and avoid recurrences.

oidance of activity or sports is not essential. Immobilization is actually contraindicated and can lead to rapid atrophy of the quadriceps muscle. Physical therapy and flexibility exercises to stretch and strengthen the quadriceps and hamstring muscles may help to alleviate stress on the tubercle and avoid recurrences. Applying ice after activity may decrease swelling, and pain can be controlled with NSAIDs. Corticosteroids should not be injected into the patellar tendon or para-apophyseal soft tissues. Parents should be provided reassurance that the condition is benign and self-limited and will resolve after closure of the proximal tibial growth plate. Rarely, an ossicle may persist after skeletal maturity that causes pain and may require excision. ACUTE RHEUMATIC FEVER Acute rheumatic fever primarily affects children of school age. The incidence of acute rheumatic fever has steadily fallen in developed countries over the past 50 years. However, sporadic cases of invasive group A β-hemolytic streptococcal infections with presumably more virulent strains mean that outbreaks of acute rheumatic fever continue to be regularly reported in North America. It is preceded by infection with FIGURE 141-33. Legg-Calvé-Perthes disease: note the flattened and radiopaque left femoral epiphysis. FIGURE 141-34. Lateral radiograph illustrating Osgood-Schlatter disease with promi nence of the tibial tuberosity in addition to ossicles separate from the anterior border of the tubercle (arrow). [Photo used with permission of Wake Medical Center, Raleigh, NC.] Tintinalli_Sec12_p0669-0996.indd 924 8/2/19 7:57 PM