Secrets – Pediatric: Orthopedics

Secrets – Pediatric: Orthopedics

CLINICAL ISSUES
1. What is torticollis?
Torticollis, also called a “cock-robin” deformity, is a combined head tilt in one direction with rotation in the opposite direction. This deformity may be fixed or flexible.
2. What is the differential diagnosis for torticollis?
Torticollis is a symptom that has a variety of underlying etiologies:

Osseous: Atlanto-occipital anomalies, unilateral absence of C1, Klippel-Feil syndrome (fusion of cervical vertebrae), atlantoaxial rotatory displacement, basilar impression
Nonosseous: Congenital muscular torticollis, Sandifer syndrome (severe gastroesophageal reflux), ocular dysfunction (strabismus, oculogyric crisis), infections (cervical adenitis, retropharyngeal abscess), central nervous system tumors, syringomyelia, Arnold-Chiari malformation, abnormal skin webs (pterygium colli)
3. An x-ray of a 10-year-old boy taken to rule out an ankle fracture reveals a 4-mm, well-circumscribed lytic lesion in the cortex of the tibia, which is away from where he is having symptoms. What is the most likely diagnosis?
There are a variety of incidental findings on x-ray that carry little clinical significance, sometimes called “incidentalomas.” The lesion described here could easily be a fibrous cortical defect also called a nonossifying fibroma. This is the most common benign tumor in childhood and typically resolves spontaneously. Very large lesions can rarely weaken the bone enough to pose a fracture risk, and a small percentage of these lesions present with a pathologic fracture.
4. What are two other common types of benign bone tumors in children?
Unicameral bone cysts (UBC) and aneurysmal bone cysts (ABC). These lesions tend to occur in the metaphyses of long bones and typically have a “bubbly” lytic appearance on x-ray although they typically have well-defined borders because they are slow growing. Both are usually treated with surgery with curettage of the cyst and placement of bone graft to facilitate healing.
5. How and why is it important to differentiate between an ABC and a UBC? Although the x-ray appearance of ABCs and UBCs can be very similar, fluid-fluid levels seen on magnetic resonance imaging (MRI) are pathognomonic for ABCs and will not be seen in UBCs (which are sometimes called “simple cysts” for this reason). The fluid-fluid levels seen in ABCs represent the two fluids in the cyst, the cyst fluid and blood. It is very important to differentiate between these two lesions before surgery! Although both lesions are benign, ABCs can be locally aggressive and have a much higher recurrence rate. ABCs are often associated with other tumors including giant cell tumor, chondroblastoma, and fibrous dysplasia. As such, typically a more aggressive open surgery will be performed for an ABC while less aggressive percutaneous procedures are often attempted for UBCs.
6. What is rickets? Rickets is the failure of osteoid to calcify in a growing child, most commonly caused by a lack of vitamin D. The adult equivalent is osteomalacia.
7. What are the physical signs that are suggestive of rickets?
The anatomic abnormalities of rickets result primarily from the inability to normally mineralize osteoid; the bones become weak and subsequently distorted. Signs of rickets include the following:
• Femoral and tibial bowing
• Delayed suture and fontanel closure
• Pectus carinatum or “pigeon breast” (anterior protrusion of the sternum)
• Frontal thickening and bossing of the forehead

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• Defective tooth enamel
• Harrison groove (a rim of rib indentation at the insertion of the diaphragm)
• Widened physes at wrists and ankles
• “Rachitic rosary” (enlarged costochondral junctions)
8. Which bones are known to develop aseptic (also called avascular) necrosis?
The osteochondroses are a group of disorders in which aseptic necrosis of epiphyses occurs with subsequent fragmentation and repair (Table 15-1). The exact cause is unknown in most cases. However, systemic steroid use has been associated with the development of aseptic necrosis. The patient usually presents with pain at the affected site.

Table 15-1. Typical Age of Onset of Osteochondroses

LOCATION
EPONYM TYPICAL AGE OF ONSET (YR)
Tarsal navicular bone K€ohler disease 6
Capitellum of distal humerus Panner disease 9-11
Carpal lunate Kienb€ock disease 16-20
Distal lunar epiphysis Burns disease 13-20
Head of femur Legg-Calvé-Perthes disease 3-5

9. What are the inheritance patterns and clinical features of osteogenesis imperfecta?
Of the several types of osteogenesis imperfecta, the most common is type IV, which occurs
in 1 in 30,000 live births. The clinical features vary and depend on the severity of the condition (Table 15-2).

Table 15-2. Types of Osteogenesis Imperfecta
TYPE INHERITANCE CLINICAL FEATURES
I Autosomal dominant Bone fragility, blue sclerae, onset of fractures after birth (most at preschool age)
Type A Without dentinogenesis imperfecta
Type B With dentinogenesis imperfecta
II Autosomal recessive Lethal in perinatal period, dark blue sclerae, concertina femurs, beaded ribs
III Autosomal recessive Fractures at birth, progressive deformity, normal sclerae and hearing

10. McCune-Albright syndrome is associated with what skeletal abnormalities? Polyostotic fibrous dysplasia (i.e., fibrous tissue replacing bones). The fibrous dysplasia occurs most commonly in the long bones and the pelvis and may result in deformity and/or increased thickness of bone. Fibrous dysplasia associated with precocious puberty and café-au-lait spots is known as McCune-Albright syndrome.
11. What are the causes of in-toeing gait (pigeon-toeing)?
In-toeing can be due to problems in the foot, tibia or hip:
Foot:
• Metatarsus adductus
• Talipes equinovarus (clubfoot)

Leg:
• Tibial torsion (internal)
Hip:
• Femoral anteversion (medial femoral torsion)
• Paralysis (polio, myelomeningocele)
• Spasticity (cerebral palsy)
• Maldirected acetabulum

Tunnessen WW Jr: Signs and Symptoms in Pediatrics, ed 3. Philadelphia, 1999, Lippincott Williams & Wilkins, pp 693–695.

12. Is in-toeing a problem?
The majority of cases of in-toeing are not pathologic problems. There is a normal range of foot placement during gait that can range from slightly internally rotated to slightly externally rotated. Many children will improve their walking as they get older: most children do not have a mature gait pattern until around age 7. Many elite runners turn their feet in when running because they are faster this way.
Most parents love this piece of information.
13. When, if ever, does in-toeing need to be treated?
In-toeing rarely requires treatment other than reassurance to the family that their child’s walking will improve with time. Femoral anteversion and tibial torsion almost never require treatment in the neurologically normal child. Traditional treatments such as the infamous boots and bars and orthopedic shoes do nothing to change the natural history of these problems. Metatarsus adductus frequently resolves in the first 2 years of life, but feet that are rigid (i.e., the foot cannot easily be manipulated into a normal position) or severe cases may require casting; straight-laced shoes; or in extreme cases, surgery. Children with extreme rotational problems or very asymmetric rotation occasionally benefit from surgery to derotate the affected bone (femur or tibia).
14. A 15-year-old with tibial pain (worse at night and relieved by nonsteroidal anti-inflammatory drugs) has a small lytic area surrounded by reactive bone formation on x-ray. What is the likely diagnosis?
Osteoid osteoma, a benign bone-forming tumor, is typically seen in older children and adolescents and exhibits a male predominance (male-to-female ratio, 2:1). Most children complain of localized pain, usually in the femur and tibia; however, arms and vertebrae may also be involved. Radiographs may demonstrate an osteolytic area surrounded by densely sclerotic reactive bone, and bone scans reveal “hot spots.” Computed tomography (CT) scans will show a “nidus” in the middle of the lesion, which is
pathognomonic for this diagnosis. The site is usually <1 cm in diameter and arises at the junction of old and new cortex. Pathologically, the lesion is highly vascularized fibrous tissue with an osteoid matrix
and poorly calcified bone spicules surrounded by a dense zone of sclerotic bone. Treatment is surgical excision.
15. What is the clinical significance of limb-length discrepancy?
A significant portion of the population has mild limb-length discrepancy. Limb-length discrepancies
of <2 cm in a skeletally mature individual usually require no treatment. However, larger discrepancies can lead to problems including limp and low back pain. Over time other problems may be seen including Achilles contractures in the short leg and late hip arthritis.
16. What are the possible causes of a limb-length discrepancy?
• Congenital anomalies: Congenital short femur, proximal femoral focal deficiency, congenital absence of fibula, posteromedial bowing of tibia, tibial hypoplasia, congenital hemihypertrophy
• Tumors: Neurofibromatosis, fibrous dysplasia, enchondromatosis, hereditary multiple exostosis, Klippel-Trénaunay-Weber syndrome
• Trauma: Physeal injuries, fracture
• Infection: Septic arthritis, osteomyelitis (the infection can damage the growth plates)
• Inflammatory: Juvenile idiopathic arthritis
17. What are the general management principles for a limb-length discrepancy?
• 0 to 2 cm: No treatment
• 2 to 6 cm: Shoe lift, epiphysiodesis

• 6 to 20 cm: Limb lengthening
• >20 cm: Prosthetic fitting
There is flexibility in these guidelines to account for factors such as environment, motivation,
intelligence, compliance, emotional stability, patient and parent wishes, predicted final height, and associated pathology in the limbs.

Friend L, Widmann RF: Advances in the management of limb length discrepancy and lower limb deformity, Curr Opin Pediatr 20:46–51, 2008. Guidera KJ, Helal AA, Zuern KA: Management of pediatric limb length inequality, ADV Pediatr 42:501–543, 1995.

18. What is a nursemaid elbow?
Also known as a “pulled elbow,” a nursemaid elbow is a subluxation of the radial head under the orbicular (or annular) ligament resulting from axial traction applied to the extended arm of a young child (Fig. 15-1). Given the pathology, some experts also prefer either the term “annular ligament entrapment” or “annular ligament displacement.” Clinically, the child is unwilling to move the affected limb (pseudoparalysis) and there is tenderness directly over their radial head. Attempts to supinate the forearm cause significant pain. The diagnosis is typically made by history and physical examination. Radiographs are normal and not indicated if the mechanism of injury is consistent with this diagnosis. If there is direct trauma or twisting trauma or if a child has significant localized tenderness or swelling on exam, a radiograph should be considered to evaluate for fracture.

Rudloe TF, Schutzman S, Lee LK, et al: No longer a “nursemaid’s” elbow: mechanisms, caregivers and prevention,
Pediatr Emerg Care 28:771–774, 2012.

Figure 15-1. Pathology of nursemaid elbow. When the arm is pulled, the radial head moves distally. When traction is discontinued, the ligament is carried into the joint. (From Kleigman RM, Stanton BF, Schor NF, et al, editors: Nelson Textbook of Pediatrics, ed 19. Philadelphia, 2011, ELSEVIER Saunders, p 2384.)

19. How is a nursemaid elbow reduced?
Two methods can be utilized. In one, the subluxed radial head is reduced by supinating the extended forearm followed by fully flexing the elbow. In the other, the forearm is hyperpronated. When there
is a successful reduction, an audible and palpable click is often present. The child will begin to use his or her arm spontaneously (usually after a few minutes of crying). Limited studies have found that the pronation method may be more effective and less painful than the supination method as a technique for reduction.

Gunaydin YK, Katirci Y, Duymaz, et al: Comparison of success and pain levels of supination-flexion and hyperpronation maneuvers in childhood nursemaid’s elbow cases, Am J Emerg Med 31:1078–1081, 2013.

20. What signs and symptoms suggest a serious cause of back pain in a child that warrants further evaluation?
Symptoms: age <4 years; pain interfering with daily activities in school, play, or athletics; pain lasting longer than 4 weeks; night pain (often associated with tumor); pain radiating down the leg; fever or other systemic symptoms; limp or altered gait; bowel or bladder changes
Signs: postural changes; clawing of the toes, gait changes, bowel and bladder habit changes, other neurologic abnormalities; reproducible point tenderness; pain with hyperextension of the back; bruising

Davis PJC, Williams HJ: The investigation and management of back pain in children, Arch Dis Child Educ Pract Ed
93:73–83, 2008.

21. What is the differential diagnosis of back pain in children?
• Infectious: Discitis, vertebral osteomyelitis, vertebral tuberculosis
• Developmental: spondylolysis, spondylolisthesis, Scheuermann kyphosis, scoliosis
• Traumatic: Herniated disc, muscle strain, fractures, vertebral apophyseal fracture
• Inflammatory: Juvenile idiopathic arthritis, ankylosing spondylitis
• Neoplastic: Eosinophilic granuloma, osteoid osteoma or osteoblastoma, aneurysmal bone cyst, leukemia, lymphoma, Ewing sarcoma, osteosarcoma
• Visceral: Urinary tract infection, hydronephrosis, ovarian cysts, inflammatory bowel disease

Thompson GH: Back pain in children, J Bone Joint Surg Am 75:928–937, 1993.

22. Do school backpacks contribute to back pain?
Probably, but this is controversial. Some experts suggest that the limits of maximum loads lifted by children should be 5% to 20% of body weight. In some studies, more than a third of students carried more than 30% of their body weight at least once during the school week. With an apparent increasing incidence of back pain in children and adolescents (particularly those with open physes), the bulging backpack may be one contributing cause.

Dockrell S, Simms C, Blake C: Schoolbag weight limit: can it be defined? J Sch Health 83:368–377, 2013.

23. What constitutes an orthopedic emergency?
There are few true emergencies in orthopedics that require immediate attention, but conditions that fall into this category include: open fractures, impending compartment syndrome, femoral neck fractures (including unstable slips of the proximal femoral physis or SCFE), dislocation of major joints (i.e., knee, hip, spine), septic arthritis, cauda equina syndrome.

KEY POINTS: PEDIATRIC ORTHOPEDIC EMERGENCIES— NO DELAY!
1. Open fracture
2. Impending compartment syndrome
3. Dislocation of major joints
4. Septic arthritis
5. Arterial injury

FOOT DISORDERS
24. Do infants and children need shoes?
Barefoot is the natural state of the foot. Humans evolved without shoes and individuals who spend most of their lives unshod have stronger feet and fewer foot deformities than those who wear shoes. Before they begin walking, infants do not need foot coverings other than to keep their feet warm. Once the child begins to walk, shoes will offer protection from the cold and from sharp objects. The AAP recommends soft, light, flexible shoes for new walkers—not bulky, heavy supportive shoes.

25. What is the most common congenital foot abnormality?
Metatarsus adductus, also known as metatarsus varus, is the most common abnormality. In patients with this condition, the forefoot is turned toward the midline as a result of adduction of the metatarsal bones at the tarsometatarsal joints. The hindfoot (heel) is normal (Fig. 15-2). Most cases are mild and flexible, with the foot easily straightened by passive stretching. A simple test to determine if the kidney- shaped curvature is within normal limits is to draw a line that bisects the heel. When extended, this line normally falls between the second and third toe space. If it falls more laterally, metatarsus adductus is present. In many cases, in utero positioning is the suspected cause of the condition. It is seen more frequently in firstborn children, presumably because primigravida mothers have stronger muscle tone in their uterine and abdominal walls.

Figure 15-2. Metatarsus adductus. (From Clark DA: Atlas of Neonatology. Philadelphia, 2000, WB Saunders, p 224.)

26. How is metatarsus adductus treated?
If the foot can be passively abducted beyond neutral, the prognosis is excellent for a spontaneous correction without any therapeutic intervention. In those feet that are stiffer, a program of passive stretching is in order. The parents are taught to hold the heel in a neutral position and manually abduct the forefoot using their thumb placed over the cuboid as a fulcrum. This exaggerated position should be held for a few seconds and the stretching repeated 10 times each session. These sessions should occur with bathing and diaper changing. If this fails to improve the foot, bracing and/or casting can be of help.
27. How is clubfoot distinguished from severe metatarsus adductus?
Clubfoot, or talipes EQUINOVARUS, is distinguished pathologically by a combination of forefoot and hindfoot abnormalities, which result in a fixed (rigid) equinus and varus deformity of the hindfoot. Metatarsus adductus is often a component of clubfeet, but in isolated metatarsus adductus the hindfoot (heel) is normal. If the ankle can be dorsiflexed to neutral or beyond, metatarsus is the most likely diagnosis.
28. How are clubfeet treated? Most clubfeet respond well to serial casting using the Ponseti method. The casts should be applied soon after birth, and they are changed weekly. Over the course of 3 to 8 casts significant improvement in the shape of the foot can be expected. About 80% of the feet that are corrected with casting will require an Achilles tenotomy to correct the equinus deformity. Those feet that are not adequately corrected with casting require a more extensive surgical release.

Smith PA, Kuo KN, Graf AN, et al: Long-term results of comprehensive clubfoot release versus the Ponseti method: which is better? Clin Orthop Relat Res 472:1281–1290, 2014.

29. What is a calcaneovalgus foot?
This common deformity, a sort of anti-clubfoot, is the result of an in utero “packaging defect” and is considered a normal variant. The deformity is the exact opposite of the clubfoot: the foot lies in an acutely dorsiflexed position, with the top of the foot in contact with the anterolateral surface of the leg. The heel is in severe valgus, and the forefoot is markedly abducted. Overall the foot is flexible, and both the heel and the forefoot can be corrected into a neutral position. Spontaneous correction is the norm. However, having parents passively stretch the foot is often beneficial (and makes the parents feel better and proactive).
30. What should be suspected when pes cavus is noted on examination? Pes CAVUS, or high-arched feet (often associated with claw toes), can result from contractures or disturbed muscle balance (Fig. 15-3). A neurologic etiology should always be considered and looked for. The differential diagnosis includes a normal familial variant, Charcot-Marie-Tooth disease, spina bifida or other spinal cord anomaly, peroneal muscle atrophy, Friedreich ataxia, Hurler syndrome, and polio. Neurology consult and/or MRI of the spine is often indicated.

Figure 15-3. Pes cavus. (From Mellion MB, Walsh WM, Shelton GL: The Team Physician’s Handbook, ed 2. Philadelphia, 1997, Hanley & Belfus, p 603.)

31. Should children with flexible flat feet be given corrective shoes?
Only very rarely. Flexible flat feet (pes PLANOVALGUS) is a common finding in infants and children and approximately 15% of adults. During weight-bearing activity, the ligaments supporting the medial longitudinal arch stretch, and the arch becomes flattened. The heel may also go into an increased valgus (outward) position. There are no radiographic parameters that define a flexible flat foot; it is felt to be a normal variant that results from ligamentous laxity. Children typically do not complain of pain, and an arch can be created easily by removing weight from the feet, having the child stand on his/her toes or by dorsiflexing the great toe. This condition is distinguished from pathologic flat feet in which lack of weight bearing does not lessen the flatness, and rigidity is present on physical examination. Prospective studies have shown that corrective shoes or orthotic insets are not necessary in young children with asymptomatic flexible flat feet because the arch can spontaneously develop during the first 8 years of life and even when it does not, arches do not change the natural history.

Dare DM, Dodwell ER: Pediatric flatfoot: cause, epidemiology, assessment and treatment, Curr Opin Pediatr 26:93– 100, 2014.
32. When should I worry about a child with flat feet? Flat feet become concerning if they are rigid (as opposed to flexible), painful, or if they cause a disability (such as decreased walking or running endurance). If any of these conditions occurs, the child should be evaluated by a specialist for possible treatment including physical therapy (to stretch the Achilles tendon and strengthen the foot and ankle muscles); orthotics; or in rare cases, surgery.

33. How does the cause of foot pain vary by age?
• 0 to 6 years: Ill-fitting shoes, foreign body, occult fracture, osteomyelitis, juvenile idiopathic arthritis (if other joints are involved), rheumatic fever (hypermobile flat foot)
• 6 to 12 years: Ill-fitting shoes, foreign body, accessory navicular bone, occult fracture, tarsal coalition (peroneal spastic flat foot), ingrown toenail, hypermobile flat foot
• 12 to 19 years: Ill-fitting shoes, foreign body, ingrown toenail, pes cavus, hypermobile flat foot with tight Achilles tendon, ankle sprains, stress fracture

Gross RH: Foot pain in children, Pediatr Clin North Am 33:1395–1409, 1986.

34. A 10-year-old boy with recurrent ankle sprains and painful flat feet should be evaluated for what possible diagnosis?
Tarsal coalition. Fusion of various tarsal bones via fibrous or bony bridges can result in a stiff foot that inverts with difficulty. When inversion of the foot is done during an examination, tenderness occurs on the lateral aspect of the foot, and peroneal tendons become very prominent. Thus, this condition is also referred to as “peroneal spastic flat foot.” Unless the condition is very severe and warrants surgery, corrective shoes are usually adequate treatment. Other possible causes of a rigid flat foot include rheumatoid arthritis, septic arthritis, posttraumatic arthritis, neuromuscular conditions, and congenital vertical talus.

FRACTURES
35. What are the fractures patterns unique to children?
Children can suffer from physeal (growth plate) fractures, buckle fractures, greenstick fractures, and plastic deformation injuries. Most fractures in children incorporate one or more of these patterns.
36. What is a buckle fracture?
Children’s bones are softer and more plastic than adult bones. Their bones can bend without actually breaking. A buckle (or torus) fracture occurs when a bone is bent (usually as a result of a fall), and compressive forces cause the cortex to actually buckle out, causing a bump in the bone. This is analogous to what happens to the sheet metal in a car involved in a collision. While this is a fracture, the bone is still in one piece and stable, which is why these fractures are often diagnosed a week or two after injury, much to the surprise and chagrin of the parents who had been ignoring their child’s complaints.
37. What is a greenstick fracture?
A greenstick is an incomplete fracture of a long bone. It is called thus because the fracture pattern is similar to what happens when you try to snap a still living branch (or green stick) in half: the branch will break on one side but not all the way through. Similarly, in a greenstick fracture only one cortex fractures while the other cortex remains intact, although usually bent.
38. What does plastic deformation mean? The softness, or plasticity, of a child’s bones allows them to bend without breaking. When you take a metal rod and bend it just a little, it tends to spring back to its original position. However, if you bend it more, it may spring back, but not all the way, leaving you with a bent rod. The same thing happens in children’s bones. Depending on how much force and energy is imparted into the bone as a result of an injury, the bone will first bend, then buckle, then break. So a little bit of force will bend the bone, leaving the child with a bent forearm (far and away the most common location for this pattern of injury). A little more force may cause the cortex to buckle, and even more force will cause a fracture line to extend across the bone. It’s important to realize that plastically deformed bones do not remodel because there is no healing response as there is when the bone is actually cracked. Therefore, patients with plastically deformed bones usually require them to be straightened (in the operating room or under sedation). This maneuver often results in a complete fracture occurring, which may require internal fixation with rods, wires or plates.
39. Where are the most frequent sites of fractures among children?
• Clavicle
• Distal radius
• Distal ulna
40. What is an open fracture? In an open fracture, the fracture site communicates with the external environment, usually as a result of the bone piercing the skin. Often times the bone pokes out than falls back beneath the skin, so any laceration of a

fracture site must be presumed to be an open fracture until proven otherwise. Open fractures have higher incidence of infection and a higher degree of soft-tissue damage when compared with closed fractures.
41. What is a toddler fracture?
A toddler fracture is a fracture of the tibia in a child 9 months to 3 years old as a result of low-energy rotational forces. Typically, these fractures have a spiral appearance and are not displaced. The
fibula is rarely fractured. The child will limp, or more commonly, refuse to bear weight. If the child is comfortable at rest, no immobilization is required, but some children (and families) will be more comfortable in a cast or splint for around 2 to 3 weeks.
42. How are growth-plate fractures classified?
The Salter-Harris classification of growth-plate (physis) injuries (Fig. 15-4) was devised in 1963. Physeal fractures can result in growth disturbances, and the probability of those happening increases as the classification goes from I to V:
• Type I: Epiphysis and metaphysis separate; usually no displacement occurs as a result of the strong periosteum; radiograph may be normal; tenderness over the physis may be the only sign; normal growth after 2 to 3 weeks of cast immobilization
• Type II: Fragment of metaphysis splits with epiphysis; usually closed reduction; casting is for 3 to 6 weeks (longer for lower extremity than upper extremity); growth usually not affected, except distal femur and tibia
• Type III: Partial plate fracture involving a physeal and epiphyseal fracture to the joint surface; occurs when growth plate is partially fused; closed reduction more difficult to achieve
• Type IV: Extensive fracture involving epiphysis, physis, metaphysis, and joint surface; high risk for growth disruption unless proper reduction (usually done operatively) is obtained
• Type V: Crush injury to the physis; high risk for growth disruption

Figure 15-4. Salter-Harris classification. (From Katz DS, Math KR, Groskin SA, editors: Radiology Secrets. Philadelphia, 1998, Hanley & Belfus, p 403.)
43. In a patient with suspected fracture, what are the key points on physical examination?
Assess “the five P’s” in the affected extremity:
• Pain and point tenderness
• Pulse (distal to the fracture)—to evaluate vascular integrity
• Pallor—to evaluate vascular integrity
• Paresthesia (distal to the fracture)—to assess for sensory nerve injury
• Paralysis (distal to the fracture)—to assess for motor nerve injury Examine for pain above and below the suspected injury site because multiple fractures can occur in
the same limb. The involved extremity should also be carefully examined for deformity, swelling, crepitus, discoloration, and open wounds. A primary concern in any evaluation is a distal neurovascular compromise, which may require immediate surgical intervention. Although the neurologic examination can be challenging in the setting of pain, especially in the younger child who is not cooperative, it is very important to do as thorough an exam as possible.
44. What are the signs of compartment syndrome?
The five P’s noted in the preceding question are seen in impending or established compartment syndrome, a condition in which circulation and function in tissues in a closed space (e.g., thigh, lower leg) is compromised by increased pressure due to swelling, which results in distal ischemia. However, the most important symptom is pain, especially pain that does not respond to pain medication and pain with passive range of motion of the digits (fingers or toes) distal to the fracture. If one waits for numbness and paralysis to make the diagnosis of compartment syndrome, it is too late—permanent damage has likely

been done. Compartment syndrome is often unrecognized in unconscious patients so a high index of suspicion must be maintained in patients with severe injuries and an altered mental status. In addition, a frightened young child or infant may be very difficult to examine. If there is any concern about compartment syndrome, the compartment pressures must be measured.
45. What is the treatment of compartment syndrome? Compartment syndrome is a true orthopedic emergency. Increased pressure in a compartment is relieved by incising the skin and fascia encompassing the involved compartment. The wound is left open and covered with sterile dressing until swelling decreases. Dressing changes, debridements, and partial wound closure are usually done in the operating room every day or two until the skin can be closed. In some cases, skin grafts are necessary.
46. How do you treat clavicle fractures? These fractures are best managed with a sling and activity restriction. Union occurs in 2 to 4 weeks, but the sling may be removed once the child is comfortable. The residual bump (fracture callus) may take up to 2 years to smooth out (remodel), but there always may be some bump left, especially in older children. Although some studies in adults have suggested improved outcomes with operative management, nonoperative outcomes are good even in older adolescents.
47. Is surgery ever indicated in clavicle fractures? Surgical treatment of clavicular fractures is a very rare event. Traditionally, surgery has been considered necessary in children in only a few extreme scenarios: open fractures, neurovascular injury, or skin compromise. In the adult, there has been growing enthusiasm supporting surgical fixation of clavicular fractures with significant shortening of the bone (>2 to 3 cm) because these can cause problems with
weakness and deformity in the affected shoulder. However, there is no similar literature to support surgery
in a pediatric population. All studies in children show close to a 100% healing rate for these fractures without surgery. Of note, studies looking at outcomes with surgery show that these cases represent approximately only 1% of all the clavicle fractures.

Randsborg P-H, Fuglesang HFS, et al: Long-term patient-reported outcome after fractures of the clavicle in patients aged 10 to 18 years, J Pediatr Orthop 34:393–399, 2014.
Kubiak R, Slongo T: Operative treatment of clavicle fractures in children: a review of 21 years, J Pediatr Orthop
2002;22:736–739.
48. A teenager who punches a wall in anger typically incurs what fracture?
Boxer fracture. This is a fracture of the distal fifth metacarpal, usually with apical dorsal angulation (Fig. 15-5). Up to 35 degrees of angulation can be accepted without compromise of function. Reduction may be held with a cast, although at times it may require pin fixation.

Figure 15-5. Boxer fracture with fracture of fifth (and fourth) metacarpal with volar displacement of the distal fragments after a punching injury. (From Katz DS, Math KR, Groskin SA, editors: Radiology Secrets. Philadelphia, 1998, Hanley & Belfus, p 440.)

49. Children who fall on outstretched arms often suffer what type of fractures?
Colles fractures. This is a group of complete fractures of the distal radius with varying displacement of the distal fragment. The fall, with the hand outstretched, wrist dorsiflexed, and forearm pronated, often results in a classic “dinner-fork” deformity of the wrist on examination.
50. What does the presence of the posterior fat pad on an elbow x-ray suggest? Of the two fat pads that overlie the elbow joint, only the anterior one typically is visible on a lateral x-ray. If fluid accumulates in the joint space, as it does in cases involving bleeding, inflammation, or fracture, the fat pads are displaced upward and outward. The position of the anterior pad changes, and the posterior pad becomes visible. In the setting of acute trauma, the presence of a posterior fat pad is associated with a nearly 75% chance of occult fracture and the elbow should be immobilized in a cast or splint with close follow-up scheduled. The most common injuries would be a radial head fracture and a nondisplaced supracondylar humerus fracture.
51. For a teenager with wrist trauma, why is palpation of the anatomic “snuff box” a critical part of the physical exam?
The anatomic snuff box (the inpouching formed by the tendons of the abductor pollicis longus and extensor pollicis longus when the thumb is abducted [in hitchhiker fashion]) sits just above the scaphoid (carpal navicular) bone. The scaphoid is the carpal bone most commonly fractured, and it is at high risk for nonunion or avascular necrosis. Snuff box tenderness, pain on supination with resistance, and pain on longitudinal compression of the thumb should increase suspicion for fracture of the scaphoid bone. Even when an x-ray is negative, if there is significant snuff box tenderness, a fracture should be suspected and the wrist and thumb immobilized. A repeat x-ray in 2 to 3 weeks may better reveal a fracture. The use of computed tomography (CT) or MRI can be used to more reliably identify a scaphoid fracture when the plain film is negative and the clinical suspicion is high.

Evenski AJ, Adamczyk MJ, Steiner RP, et al: Clinically suspected scaphoid fractures in children, J Pediatr Orthop
29:352–355, 2009.
52. Name the eight carpal bones of the wrist.
Disdaining some of the classic (mostly obscene) mnemonics, remember what will happen if a wrist fracture is missed: Sinister Lawyers Take Physicians To The Court House, which helps identify the bones in order of proximal to distal, lateral to medial: scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, and hamate.
53. What is the difference between open and closed reductions?
A fracture reduction means realignment of the bone to its original shape. A closed reduction occurs by simply pushing on the bone and holding it in place with a splint or a cast. This may be done in the emergency department (ED) or the operating room; some form of anesthesia is usually required. An open reduction implies that an incision is required to expose the fracture site, help realign the bone, and use an internal implant (if needed) to stabilize the bone. This often occurs when the fracture is already exposed (an open fracture), when there is soft tissue interposed between the fragments blocking reduction, or when a joint surface is involved. Joints do not remodel and perfect alignment is critical to prevent post-traumatic arthritis. Other indications for open reduction include children with polytrauma (multiple fractures and/or head injuries to facilitate their mobilization) and those with Salter-Harris III and IV fractures where a good reduction can reduce the risk of physeal arrest.
54. In pediatric fractures, what amount of angulation is acceptable before reduction is recommended?
Acceptable angulation or displacement varies with the location of the fracture and the child’s age. Younger children have remarkable healing potential to remodel with minimal to no residual deformity or limitation of rotation. As a rule, wrist fractures in children up to 8 years old, as much as 30 degrees of angulation in the plane of motion will heal satisfactorily without reduction. This means that a fracture that is flexed or extended in the wrist (in the direction the wrist typically moves) can be expected to model well. Less angulation is accepted in the midshaft of the forearm; typically 15 to 20 degrees will be allowed. However, displacement with angulation towards the radius or ulna will not remodel so reliably and rotational malalignment will not remodel at all. The degree of remodeling diminishes with age and growth remaining. In general, fractures closer to the growth plate will remodel more readily than midshaft fractures.

Boutis K: Common pediatric fractures treated with minimal intervention, Pediatr Emerg Care 26:152–162, 2010.

55. In which fractures will remodeling of bone not occur? Remodeling, or reshaping of the bone to its original configuration, is a common phenomenon in pediatric fractures, which lessens the need for surgery for many fracture patterns. Remodeling occurs most readily when the fracture is close to the growth plate, and the deformity is in the plane of motion (e.g., a distal femur fracture is bent in flexion as opposed to being in varus or valgus). Interestingly, extension-type supracondylar humerus fractures, the most common surgically treated elbow fracture in children, do not remodel very well even though they are close to the physis, and the deformity is in the plane of motion (extension usually). The following fractures also have a low chance of remodeling and may require closed or open reduction: intra-articular fractures (these must always be reduced anatomically to preserve joint function); plastic deformation (see above), and fractures with excessive shortening or rotation. Angulation and translation deformities may remodel, but if the severity is too great, they may not remodel completely with the sequelae of residual deformity and possible dysfunction.

56. How long should fractures be immobilized?
Children’s fractures generally heal more quickly than their counterparts in adults. The exact length of immobilization depends on several variables, including the child’s age, the location of the fracture, and the type of treatment. As a rule of thumb, physeal, epiphyseal, and metaphyseal fractures heal more rapidly than diaphyseal fractures because they have a better blood supply. On average, epiphyseal, physeal, and metaphyseal fractures heal in children within 3–5 weeks, whereas diaphyseal fractures may heal within 4–6 weeks. The big exception is the tibial shaft fractures, which can take up to 12 weeks to heal even in healthy children.

Castroom: The Casters and Bracers Home: www.castroom.net. Accessed on Mar. 27, 2015.

57. How long do fractured clavicles and femurs take to heal?
• Newborn: CLAVICLE, 10 to 14 days; femur, 3 weeks
• 16-year-old child: CLAVICLE, 6 weeks; femur, 6 to 10 weeks

HIP DISORDERS
58. Why has DDH replaced CHD? The term DEVELOPMENTAL dysplasia of the hip (DDH) has replaced congenital hip dislocation (CHD) to reflect the evolutionary nature of hip problems in infants during the first months of life. About 2.5 to 6.5 infants per 1000 live births develop problems, and a significant percentage of these are not present on neonatal screening examinations. Therefore, the overt pathologic process may not be present at birth, and the term congenital does not apply to all cases of hip dysplasia and has been dropped. As such, periodic examination of the infant’s hip is recommended at each routine well-baby examination until the age of 1 year.
DDH also refers to the entire spectrum of abnormalities involving the growing hip, ranging from dysplasia to subluxation to dislocation of the hip joint. Unlike CHD, DDH refers to alterations in the hip growth and stability in utero, during the newborn period, and during infancy. If other diseases are involved (e.g., cerebral palsy), “hip dysplasia” alone is a sufficient term. Hip dislocation as a result of neurologic disease or joint contracture syndromes (e.g., spina bifida, arthrogryposis) is more correctly labeled “teratologic dislocation.”

Nemeth BA, Narotam V: Developmental dysplasia of the hip, Pediatr REV 33:553–561, 2012.

59. What are the Ortolani and Barlow maneuvers? The most reliable clinical methods of detection remain the Ortolani reduction and the Barlow provocative maneuvers. The infant should be lying quietly supine. Both examinations begin with the hips flexed to 90 degrees. To perform the Ortolani MANEUVER, the hip is abducted, as the examiner’s index finger gently pushes up on the greater trochanter. This is a reduction maneuver that allows a dislocated femoral head to “clunk” back into the acetabulum (Fig. 15-6, A). The Barlow MANEUVER is performed by adducting the flexed hip and gently pushing the thigh posteriorly in an effort to dislocate the femoral head (Fig. 15-6, B). After 3 to 6 months of age, these tests are no longer useful because the hip becomes fixed in its dislocated position over time.

A
Figure 15-6. A, Ortolani maneuver. B, Barlow maneuver. (From Staheli LT, editor: Pediatric Orthopaedic Secrets.
Philadelphia, 1998, Hanley & Belfus, p 166.)

KEY POINTS: THE FOUR F’ S OF INCREASED RISK FOR DEVELOPMENTAL DISLOCATION OF THE HIP
1. First born
2. Female
3. Funny presentation (breech)
4. Family history (positive for developmental dysplasia of the hip)

60. What is a positive Galeazzi sign?
The Galeazzi test is performed by flexing both hips and knees together while evaluating the relative height of the knees. A positive Galeazzi sign is present if one knee is significantly higher than the other. This can mean one of two things: the hip on the low side is dislocated or the femur on the low side is short. As opposed to the Ortolani and Barlow signs, the Galeazzi sign remains positive, and in fact usually becomes more obvious, as the child gets older.

61. What is the significance of a “hip click” in a newborn?
A hip click is the high-pitched sensation felt at the very end of abduction when testing for development dysplasia of the hip with the Barlow and Ortolani maneuvers; it occurs in 10% of newborns. Classically, it is differentiated from a hip “clunk,” which is heard and felt as the hip goes in and out of joint.
Although a debatable point, the hip click is felt to be benign. Its cause is unclear and may be the result of movement of the ligamentum teres between the femoral head and the acetabulum or the hip adductors as they slide over the cartilaginous greater trochanter. Worrisome features that might warrant evaluation (e.g., hip ultrasound, hip x-ray) include late onset of the click, associated orthopedic abnormalities, and other clinical features suggestive of developmental dysplasia (e.g., asymmetric skin folds/creases, unequal leg length).

Witt C: Detecting developmental dysplasia of the hip, ADV Neonatal Care 3:65–75, 2003.

62. What is the most reliable physical finding for a dislocated hip in the older child?
Limited hip abduction. This is the result of shortening of the adductor muscles.

63. What other diagnostic signs are suggestive of a dislocated hip?
• Asymmetry of the thigh and gluteal folds: However, these may be present in many normal infants and it is an unreliable sign if all other tests are normal.
• Waddling gait, hyperlordosis of lumbar spine: This is seen in older patients with bilateral dislocations.
• Unilateral toe walking is consistent with a significant leg length discrepancy as can be seen in a unilateral hip dislocation

64. What radiographic studies are most valuable for diagnosing DDH during the newborn period?
In infants <6 months old, the acetabulum and the proximal femur are predominantly cartilaginous and thus not visible on plain x-ray. In this age group, these structures are best visualized with ultrasound.
In addition to morphologic information, ultrasound provides dynamic information about the stability of the hip joint.

Omero˘glu H: Use of ultrasonography in developmental dysplasia of the hip, J Child Ortho 8:105–113, 2014.

65. Should all infants be routinely screened by ultrasound for DDH?
The answer is not clear. Because physical examination is not completely reliable and the incidence of late-diagnosed DDH has not declined, some investigators have recommended routine ultrasonographic screening. However, others argue that ultrasonography can lead to overdiagnosis and treatment.
At present, the issue remains controversial. Universal screening is more commonly done in Europe, whereas in the United States, selective screening on the basis of risk factors and physical examination findings is more the norm.

Shorter D, Hong T, Osborn DA: Screening programmes for developmental dysplasia of the hip in newborn infants, Cochrane Database Syst REV 9:CD004595, 2011.

66. Who is at a higher risk for DDH?
Dislocated, dislocatable, and subluxable hip problems occur in about 1% to 5% of infants; 70% of dislocated hips occur in girls, and 20% occur in infants born in breech position. Other risk associations include the following:
• Congenital torticollis
• Skull or facial abnormalities
• First pregnancy
• Positive family history of dislocation
• Metatarsus adductus
• Calcaneovalgus foot deformities in infants <2500 g
• Amniotic fluid abnormalities (especially oligohydramnios)
• Prolonged rupture of membranes
• Large birth weight

MacEwen GD: Congenital dislocation of the hip, Pediatr REV 11:249–252, 1990.

67. What is the recommended timing for ultrasound evaluation when screening is indicated?
The AAP recommends both static and dynamic assessments 3 weeks after birth. The American College of Radiology endorses ultrasound 2 or more weeks after birth. Earlier use of ultrasound can result in a high rate of false-positive studies due to physiologic ligamentous laxity, which resolves spontaneously.

Nemeth BA, Narotam V: Developmental dysplasia of the hip, Pediatr REV 33:553–561, 2012.

68. How is DDH treated?
If the hip is dislocated, the first goal is to obtain a reduction and maintain that reduction to provide an optimal environment for femoral head and acetabular development. This is accomplished by keeping the legs abducted and the hips and knees flexed. The most commonly used device is a Pavlik harness for infants younger than age 6 months. Frequent follow-up is necessary for harness adjustments. Early initiation of harness therapy (at <2 months of age) results in stable hips in >95%
of cases of DDH.
Double and triple diapers have no role in the treatment of DDH; they provide the parents with a false sense of security and do not provide reliable stabilization or positioning. If the hip is merely

shallow or loose and not frankly dislocated, the treatment is the same, but the harness or splint can come off once a day for an hour for bathing or play time.

Cooper AP, Doddabasappa SN, Mulpuri K: Evidence-based management of developmental dysplasia of the hip, Orthop Clin North Am 45:341–354, 2014.

69. What is the natural history of untreated DDH? A child with a unilateral hip dislocation may have a leg-length discrepancy and painless (Trendelenburg) limp throughout childhood and young adulthood. If the hip is subluxed, osteoarthritis of the hip joint may develop at some point during the third through fifth decades of life. Hip fusion and total hip arthroplasty are surgical treatment options for the symptomatic hip in young adults. Children with bilateral DDH often have no leg-length inequality and no appreciable limp. They tend to walk with hyperextension of the lumbar spine (hyperlordosis) and have a waddling gait. As with patients with unilateral dislocations, these patients tend to develop early osteoarthritis. Total hip arthroplasty is the treatment of choice for adults with symptomatic bilateral DDH.
70. What is the significance of a Trendelenburg gait?
A Trendelenburg gait results from functionally weakened hip abductor muscles. It is commonly seen in children with a dislocated hip and Legg-Calvé-Perthes disease. With a dislocated hip, the abductor muscles are at a mechanical disadvantage and are effectively weakened, which
makes it difficult for them to support the child’s body weight. As a result, the pelvis tilts away from the affected hip. In an effort to minimize this imbalance during the stance phase of gait, children lean over the affected hip. This constitutes a positive Trendelenburg sign (Fig. 15-7).

Negative Positive

Figure 15-7. Trendelenburg sign. The pelvis tilts toward the normal hip when weight is borne on the affected side. (From Goldstein B, CHAVEZ F: Applied anatomy of the lower extremities, Phys Med Rehabil State Art Rev 10:601–603, 1996.)
71. What is the most common cause of a painful hip in a child <10 years old?
Transient synovitis is a self-limited inflammatory condition that occurs before adolescence, has no
known cause, and generally has a benign clinical outcome. Some theorize that it is an immune response to a viral illness, and many patients give a history of having a recent viral illness; however, viral illnesses are very common in childhood. This disorder, although benign, can cause considerable anxiety among physicians and family members during its clinical course because it can mimic other, more sinister, conditions such as septic arthritis, osteomyelitis, Legg-Calvé-Perthes disorder, juvenile idiopathic arthritis, slipped capital femoral epiphysis, and tumor. It may occur anytime from the toddler age group to the late juvenile years, but the peak age of onset is between 3 and 6 years, and it is more common among boys. Acute transient synovitis remains a diagnosis of exclusion. Treatment consists of rest and calming of the synovitis with anti-inflammatory agents. Most patients experience complete resolution of their symptoms within 2 weeks of onset; the remainder may have symptoms of lesser severity for several weeks.

Nouri A, Walmsley D, Pruszczynski B, et al: Transient synovitis of the hip: a comprehensive review, J Pediatr Orthop B
23:32–36, 2014.

72. How can transient synovitis be differentiated from septic arthritis?
See Table 15-3.

Table 15-3. Transient Synovitis versus Septic Arthritis
TRANSIENT SYNOVITIS SEPTIC ARTHRITIS
History Preceding upper respiratory infection Tlow-grade fever
Hip or referred knee pain Limp Fever
Usually large joint involvement (hip, ankle, knee, shoulder, elbow)
Physical Refusal to bear weight
Can delicately elicit range of motion in affected hip joint Exquisite pain, swelling, warmth Marked resistance to mobility
Laboratory ESR normal or mildly elevated ESR markedly elevated
Mild peripheral leukocytosis Leukocytosis with left shift
Negative blood culture Often positive blood culture
Joint fluid cloudy Joint fluid purulent
Negative Gram stain Often positive Gram stain
ESR, Erythrocyte sedimentation rate.

73. What is LCP disease?
LCP disease (also called Perthes, Legg-Perthes or Legg-Calvé-Perthes after the three physicians who independently described it) is a disorder of the femoral head of unknown etiology that is characterized by ischemic necrosis, collapse, and subsequent repair (Fig. 15-8). Children typically present with a limp that is often painless. Over time they often develop pain that localizes to the groin or is referred to the thigh or knee.

Figure 15-8. Anteroposterior view of the pelvis demonstrates fragmentation and irregularity of the left femoral head in a patient with Legg- Calvé-Perthes disease. The right hip is normal. (From Katz DS, Math KR, Groskin SA, editors: Radiology Secrets. Philadelphia, 1998, Hanley & Belfus, p 405.)

74. What are the pathologic stages of LCP disease? LCP is a condition of aseptic necrosis of the femoral head involving children primarily between the ages of 4 and 10 years.
• Incipient or synovitis stage: Lasting 1 to 3 weeks, this first stage is characterized by an increase in hip-joint fluid and a swollen synovium associated with reduced hip range of motion.
• Avascular necrosis: Lasting 6 months to 1 year, the blood supply to part (or all) of the head of the femur is lost. That portion of the bone involved dies, but the contour of the femoral head remains unchanged.
• Fragmentation or regeneration and revascularization: In the last and longest pathologic stage of LCP, which lasts 1 to 3 years, the blood supply returns and causes both the resorption of necrotic bone and the laying down of new immature bone. As the dead bone is removed, the integrity of the head is weakened and it collapses. Permanent hip deformity can occur during this last stage.
It is important to note that plain radiographs may lag behind the progression of the disorder by as much as 3 to 6 months. Radionuclide bone scans and MRI are much better tests because ischemia and avascular necrosis can be detected much earlier.

75. What is the prognosis for children with LCP disease?
The two main prognostic factors for LCP disease include the age of the child at diagnosis and the amount of epiphyseal involvement. Children <6 years of age tend to have a more favorable prognosis, and those with less epiphyseal involvement also tend to have a better prognosis. Epiphyseal involvement has been classified by Salter into type A (those with <50% epiphyseal involvement) and type B (those with >50% head involvement).
76. What condition does the child in Figure 15-9 have? This is femoral anteversion (or medial femoral torsion), which is a common cause of in-toeing in younger children. The child is demonstrating the reverse tailor, or “W” position, which is a sign of the internally rotated hip.

Staheli LT: Torsional deformity, Pediatr Clin North Am 33:1382, 1986.

Figure 15-9. Reverse tailor position or “W” position.

77. How is the extent of femoral anteversion measured?
With the child lying prone and knees flexed at 90 degrees, the hip normally cannot be rotated internally (i.e., feet pushed outward) more than 60 degrees (angle A in Fig. 15-10, A). In addition, external rotation (angle B in Fig. 15-10, B) should exceed 20 degrees. A normal child averages approximately 35 degrees. Motion outside these ranges indicates that the cause of in-toeing is likely the result of physiologic femoral anteversion (or, less commonly, hip capsular contractions as are seen in patients with cerebral palsy).

Figure 15-10. Measurement of femoral anteversion. (From Dormans JP: orthopaedic management of children with cerebral palsy, Pediatr Clin North Am 40:650, 1993.)

78. Is sitting in the “W” position harmful? In a word, no. While there is great confusion about this amongst many physicians and patients alike, there is absolutely no evidence that sitting in the “W” position has a harmful effect on the development of the hip and knee. Similarly use of special orthopedic shoes or the infamous boots and bars that hold the feet turned in has no effect on the bony alignment of the proximal femur.

79. Is there ever an indication to treat femoral anteversion?
The neurologically normal child almost never requires treatment for anteversion. While they may walk with their feet turned in, especially early in life, this tends to improve as they age and improve in strength, coordination, and balance. An exception is the child with so-called miserable malalignment syndrome who has severe femoral anteversion along with external tibial torsion. This child walks with their feet straight ahead (the tendency to in-toe is counterbalanced by the external rotation of the foot through the tibia), but the knees are pointed in and this places severe stress across the patellofemoral joint. Significant knee pain and disability follow. The treatment is quite significant, involving osteotomies of the femurs and tibias, but most patients respond well with improved knee mechanics and decreased pain.
80. What symptoms do children with slipped capital femoral epiphysis (SCFE) have? SCFE involves progressive displacement of the hip with external rotation of the femur on the epiphyseal growth plate. The patient has intermittent or constant hip, thigh, or knee pain that has often been present for weeks or months. A limp, a lack of internal rotation, and an inability to flex the hip without also abducting may be noted. It is important to realize that any patient with knee pain may have underlying hip pathology.
81. What systemic conditions are associated with SCFE?
Children with SCFE tend to have delayed skeletal maturation and obesity and usually present between the ages of 8 to 14 years. It is more common in boys and in black children. Systemic conditions associated with SCFE include hypothyroidism, panhypopituitarism, hypogonadism, rickets, and irradiation.
82. What does FAI stand for?
Femoral acetabular impingement syndrome. This is a relatively recently recognized entity thought to be a significant cause of hip pain and disability in adolescents and young adults. Similar to the way the rotator cuff of the shoulder can be damaged when impinged between the humeral head and acromion, the labrum of the hip (a structure analogous to the meniscus in the knee) can be torn when pinched between the acetabulum and femoral head or neck.

Philippon MJ, Patterson DC, Briggs KK: Hip arthroscopy and femoroacetabular impingement in the pediatric patient,
J Pediatr Orthop 33S: S126–S130, 2013.

83. What new treatments are available for the treatment of hip pathology including DDH, FAI, and SCFE?
Over the last decade, hip arthroscopy has come into much more frequent use to diagnose and treat hip pain due to labral tears and to recontour the bony aspects of the hip joint when some types of dysplasia exist. Even more recently, some hip centers around the country have been describing their experience with repairing hip pathology through surgical dislocation of the hip. This technique has been eschewed in the past because of concerns of osteonecrosis of the femoral head as a complication. However, newer techniques have shown extremely low rates of this complication and this procedure allows more direct and effective treatment of many hip problems including unstable SCFE and FAI.

Jayakumar P, Ramachandran M, Youm T, et al: Arthroscopy of the hip for paediatric and adolescent disorders: current concepts, J Bone Joint Surg Br 94:290–296, 2012.

INFECTIOUS DISEASES

KEY POINTS: OSTEOMYELITIS
1. The most common causative organisms in healthy children are Staphylococcus aureus and beta-hemolytic streptococci.
2. In children (unlike adults), spread of bacteria to bone is hematogenous rather than by local trauma.
3. In children with a puncture wound through a sneaker and osteomyelitis, think of Pseudomonas aeruginosa; however, the most common organism is still S. aureus.

4. Because of intravascular sludging and infarction, patients with sickle cell disease are at increased risk, especially for Salmonella infections.
5. Bone changes on x-ray may not occur for 10 to 15 days.

84. What percentage of septic arthritis is “culture negative”?
Several studies have established that 30% to 60% of patients with clinically apparent septic arthritis have negative cultures of joint fluid. Reasons (both postulated and confirmed) for this observation include the fastidious nature of some causes of infectious arthritis (e.g., Kingella kingae), the loss of viability of some organisms on transport to the laboratory (e.g., Neisseria species), and perhaps a substance or cell population in the aspirate fluid that is bacteriostatic during in Vitro culture conditions. Prompt processing of specimens and the use of several culture techniques (e.g., solid media plus liquid-culture systems such as those used for blood cultures) can increase the yield
of joint fluid cultures.
85. Where does acute hematogenous osteomyelitis most commonly localize in children?
Approximately two-thirds of all cases involve the femur, tibia or humerus.
86. What is the most common cause of acute hematogenous osteomyelitis?
Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA), is responsible for 70% to 90% of cases for which a bacterial pathogen is identified. Most cases of MRSA infection have additional virulence factors, such as Panton-Valentine leukocidin, which causes tissue necrosis. A variety of other organisms may be involved but rates of Haemophilus influenzae type b and S. pneumonia have declined since universal vaccination against these pathogens began. Kingella kingae (an anaerobic, β-hemolytic, gram-negative organism) is the second most common cause (beyond
gram-positive cocci) of osteoarticular infections, particularly septic arthritis, in children younger than age 4 years in the United States. For children with sickle cell disease, Salmonella is an important cause of infection. Neonatal causes are more varied compared with older children, with S. agalactiae, coagulase- negative staphylococci, and gram-negative bacilli as additional possible causes. Fungal causes are rare.

Yagupsky P, Porsch MA, St. Geme III JW: Kingella kingae: an emerging pathogen in young children, Pediatrics
127:557–565, 2011.
Harik NS, Smeltzer MS: Management of acute hematogenous osteomyelitis in children, Expert REV Anti Infect Ther
8:175–181, 2010.

87. How often are blood cultures positive in patients with osteomyelitis?
Blood cultures are positive 50% of the time or less. Because this rate is relatively low, direct bone aspiration should be strongly considered, especially in the setting of an abscess. Aspiration raises the yield to 70% to 80% and can facilitate antibiotic therapy.
88. As osteomyelitis progresses, how soon do x-ray changes occur?
• 3 to 4 days: Deep muscle plane shifted away from periosteal surface
• 4 to 10 days: Blurring of deep tissue muscle planes
• 10 to 15 days: Changes in bone occur (e.g., osseous lucencies, punched-out lytic lesions, periosteal elevation)
• >30 days: Bone sclerosis may be evident
89. What is the best way to confirm the diagnosis of osteomyelitis?
Bone infections in children are typically accompanied by fever, local pain, and decreased use of the affected body part (e.g., limp or failure to bear weight). Although point tenderness is often elicited, plain radiographs may appear normal during the first 10 to 14 days of infection, until a sufficient portion of cortex is damaged and the periosteal reaction becomes apparent. Early during the course of infection, other imaging studies (triphasic radioisotope scanning with 99mtechnetium, CT or MRI) and/or direct aspiration with Gram stain and culture can be of use for confirming the diagnosis. MRI is especially valuable in the assessment because it can simultaneously assess the osseous, articular, and muscular structures without ionizing radiation exposure (Fig. 15-11).

Figure 15-11. MRI image of the distal femur showing metaphyseal lesion (arrow) and overlying inflammatory edema of muscles, consistent with osteomyelitis. (From Bergelson JM, Shah SS, Zaoutis TE: Pediatric Infectious Diseases: The Requisites in Pediatrics.
Philadelphia, 2008, ELSEVIER Mosby, p 239.)

90. How long should antibiotics be continued in patients with osteomyelitis and septic arthritis?
The precise answer is unclear. Traditionally, a minimum of 4 to 6 weeks was believed to be necessary for the treatment of S. aureus infections. Newer studies have indicated that a combination of intravenous and oral therapy for 3 to 4 weeks is associated with therapeutic success in uncomplicated cases.
Longer durations may be required if there is delayed or incomplete surgical evacuation or distant foci of infection (e.g., endocarditis).

Peltola H, Pääkh€onen M: Acute osteomyelitis in children, N Engl J Med 370:352–360, 2014.

91. Which marker, C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR), is more sensitive to assess inflammation both diagnostically and therapeutically?
C-reactive protein. CRP has a serum circulation life of approximately 1 day. The ESR is most influenced by the fibrinogen level, which has a circulatory life of approximately 4 days. Thus, the ESR may be normal or only mildly elevated during the first days of evolving osteomyelitis and later declines more slowly. CRP rises more quickly in the setting of infection and then declines more quickly with appropriate therapy.

Conrad DA: Acute hematogenous osteomyelitis, Pediatr REV 31:464–470, 2010.

92. When is open surgical drainage indicated in cases of osteomyelitis?
• Abscess formation in the bone, subperiosteum, or adjacent soft tissue
• Bacteremia persisting more than 49 to 72 hours after the initiation of antibiotic treatment
• Continued clinical symptoms (e.g., fever, pain, swelling) after 72 hours of therapy
• Development of a sinus tract
• Presence of a sequestrum (i.e., detached piece of necrotic bone)

Darville T, Jacobs RF: Management of acute hematogenous osteomyelitis in children, Pediatr Infect Dis J 23:255–257, 2004.

93. Why are treatment failures more common in osteomyelitis than in septic arthritis?
• Antibiotic concentrations are much greater in joint fluid than in inflamed bone. Concentrations in joint fluid may actually exceed peak serum concentrations, whereas those in bone may be significantly less than serum concentrations.
• Devitalized bone may serve as an ongoing nidus for infection, and it has no blood flow to bring in antibiotics.
• Diagnosis of osteomyelitis is more likely to be delayed than that of septic arthritis.

94. How is the diagnosis of discitis established?
Discitis, which is the infection and/or inflammation of the intervertebral disc, most commonly occurs in children between the ages of 4 and 10 years. The etiology is often unclear, but a bacterial cause (particularly S. aureus) is identified by blood cultures in about 50% of cases. The diagnosis can be difficult because the symptoms can be vague and vary greatly. Symptoms include generalized back pain with or without localized tenderness, limp, refusal to stand or walk, back stiffness with loss of lumbar lordosis, abdominal pain, and unexplained low-grade fever.
As with osteomyelitis, a helpful laboratory test is an elevated CRP or ESR. White blood cells may often be normal, and early x-rays (<2 to 4 weeks of symptoms) may not show changes. Technetium-99 bone scans will demonstrate abnormalities early during the course of illness. MRI studies can help distinguish between discitis and vertebral osteomyelitis.
Treatment consists of 3 to 6 weeks of antistaphylococcal antibiotics, with variable amounts of immobilization and bracing to control symptoms. Persistent or atypical cases may require biopsy to identify the etiology, but this is unusual.

Early SD, Kay RM, Tolo VT: Childhood diskitis, J Am Acad Orthop Surg 11:413–420, 2003.

95. What is the most important variable that influences mortality in necrotizing fasciitis? Time to surgical debridement. Necrotizing fasciitis is a relatively uncommon deep soft-tissue infection that can rapidly cause necrosis of fascial planes and surrounding tissue. The infection most commonly follows trauma, but even minor insults (e.g., scrape, insect bite) can be implicated. High clinical suspicion is key to early diagnosis. Pain out of proportion to clinical findings is an important clue to the diagnosis. Aggressive and early surgical debridement, coupled with antibiotic therapy, constitute the primary treatment for this disease, which has been called “flesh-eating bacteria syndrome” in the popular media.

Bellaplanta JM, Ljungquist K, Tobin E, et al: Necrotizing fasciitis, J Am Acad Orthop Surg 17:174–182, 2009.

96. What is the role of bone scintigraphy in children with obscure skeletal pain? In the child with vague symptoms who is not clearly localizing to a specific anatomic location, a bone scan can help localize an abnormality in the bones, joints, or soft tissues. Once localized, the region can be further evaluated with three-dimensional imaging, if indicated, such as MRI or CT scan. Bone scans are very sensitive but not very specific. So, a negative bone scan makes the likelihood of a serious problem such as infection or tumor unlikely, which can be comforting to the physician and family. A bone scan should be considered only after a careful history and physical examination have been performed and plain x-rays of the abnormal area are obtained. The scan is most useful for ruling out an occult infection or bone tumor.
97. What are the phases of a bone scan?
There are three phases in a bone scan defined by the time elapsed since injection of the radionuclide dye.
• Phase I—Angiographic phase: During the first few seconds, the dye passes through the large blood vessels and provides early assessment of regional vascularity and perfusion.
• Phase II—Blood pool phase: Usually obtained during the first minutes after an injection, this phase highlights the movement of the dye into the extracellular spaces of soft tissue and bone.
• Phase III—Delayed phase: By 1.5 to 3 hours after injection, the dye localizes in the bone with minimal soft-tissue imaging.
The three-phase process is used to differentiate soft tissue from bony abnormalities. At times, a Phase IV study may be done by rescanning for the same dye at 24 hours, which further minimizes soft-tissue background activity.

KNEE, TIBIA, AND ANKLE DISORDERS
98. What is the difference between valgus and varus deformities? Some things seem to be destined to be learned, forgotten, and relearned many times as a rite of passage: the Krebs cycle is one; this is another. The terms refer to angular deformities of the musculoskeletal system. If the distal part of the deformity points toward the midline, the term is VARUS. If the distal part points away from the midline, it is VALGUS. For example, in patients with knock knees, the lower portion of the deformity points away, so the term is genu valgum.

Another method is to consider the body in the supine (anatomic) position. Draw a circle around the body. All angles conforming to the curve of the circle are VARUS; all angles going against the circle are VALGUS. Bowleggedness conforms to the circle around the body and is, therefore, genu varum.
99. Are children normally knock-kneed or bowlegged?
The answer is yes. Both can be normal depending on the age of the child. Most children at birth are bowlegged (genu varum) up to 20 degrees, but this tendency progressively diminishes until about 24 months, when the trend toward knock knees (genu valgum) begins. Knock knees are most noticeable at around the age of 3 years (up to 15 degrees) and then begin to diminish. By 8 years of age, most children are—and will remain—in neutral alignment, meaning that with their knees extended their knees and ankles both touch (Fig. 15-12).

Figure 15-12. Development of the tibiofemoral angle during growth. (From Bruce RW, Jr: Torsional and angular deformities, Pediatr Clin North Am 43:875, 1996.)

20°
15°
10°
5°
0°
5°
10°
15°
20°

Age (years)

100. Which bowlegged infants or toddlers require evaluation?
Radiographs should be considered if bowleggedness demonstrates any of the following features:
• Present after 24 months (the age when most children start to develop physiologic genu valgum)
• Progressive varus develops after age 1 as the infant begins to bear weight and walk
• Unilateral deformity
• Visually >20 degrees of varus angulation across the knee It’s important to remember that clinical or radiographic evaluation of alignment in the legs requires
the knees to be pointed straight ahead. If the knees are pointed in or out, flexion at the knee can be easily mistaken for bowing of the legs.
101. What are the causes of pathologic genu varum (bowleggedness) or genu valgus (knock knees)?
Genu varum
• Physiologic bow legs
• Infantile tibia vara
• Hypophosphatemic rickets
• Metaphyseal chondrodysplasia
• Focal fibrocartilaginous dysplasia
Genu valgum
• Hypophosphatemic rickets
• Previous metaphyseal fracture of the proximal tibia (Cozen fracture)
• Multiple epiphyseal dysplasia
• Pseudoachondroplasia

Sass P, Hassan G: Lower extremity abnormalities in children, Am Fam Physician 68:461–468, 2003.

102. Which children are more likely to develop Blount disease?
Tibia VARA, or Blount disease, is a medial angulation of the tibia in the proximal metaphyseal region as a result of a growth disturbance in the medial aspect of the proximal tibial epiphysis. In the

infantile type, the child is usually an obese early walker, and he or she develops pronounced bowlegs during the first year of life. Black females are particularly at risk for severe deformity. In the adolescent variety, the onset occurs during late childhood or early adolescence, and the deformity is usually unilateral and milder. While bracing may be effective in some infantile cases diagnosed in the first
2 years of life, correction of severe deformity usually requires surgical intervention.
103. How does tibial torsion change with age?
Tibial torsion, the most common cause of in-toeing in children between the ages of 1 and 3 years, gradually rotates externally with age. For excessive internal rotation, bracing was used extensively in the past, but its efficacy is questionable because the natural history of the condition is self-resolution.
Measurement is done by measuring the angle made by the long axis of the foot and the thigh when the knee is flexed 90 degrees.
104. How effective is the Denis Browne splint for the treatment of tibial torsion? Not at all. The splint consists of a metal bar connected to shoes and holds the feet in varying degrees of external rotation. The splint was used frequently in the past for children with internal tibial torsion. However, there is absolutely no scientific evidence that this device alters the natural history of tibial torsion, and the use of this device for treatment of tibial torsion by pediatric orthopedics has essentially disappeared.
105. Why are ligamentous injuries less common in children?
In children, ligaments tend to be stronger than the cartilaginous growth plates, and thus the growth plate will often fail (i.e., fracture) before the ligament tears.
106. How are ankle sprains graded?
Between 80% and 90% of ankle sprains are the result of excessive inversion and/or plantar-flexion resulting in injury to the lateral ligaments (anterior talofibular and calcaneofibular). A grade 1 ankle sprain is a mild, partial tear of the ankle ligament and results in no instability. A grade 2 sprain is a high grade partial tear. Clinically differentiating between a grade 1 and 2 can be challenging. A grade 3 sprain is a complete tear of the ligament. This will result in some instability of the ankle, which can be detected with the ankle drawer test. This test is performed by immobilizing the lower tibia with one hand as the other hand grasps the heel and pulls the foot forward. There is always some motion (test the unaffected side to get an idea of what is normal for that patient) but with a complete tear, there is marked laxity with a poor endpoint.
107. Which ankle sprains should be evaluated with an x-ray?
More than 5,000,000 radiographs are estimated to be taken annually in children and adults for ankle injuries. Various guidelines have been proposed including the Low Risk Ankle Rules (LRAR) and the Ottawa Ankle Rules. The LRAR advises that x-rays are not necessary if a child has swelling and tenderness that is isolated to the distal fibula and/or adjacent lateral ligaments distal to the tibial anterior joint line. The Ottawa Rules advise obtaining an x-ray if there is malleolar pain and one or both of the following conditions is present: (1) the inability to bear weight for four steps immediately after the injury and during office or ED evaluation; and/or (2) bone tenderness at the posterior edge or tip of either malleolus. Use of these simple criteria can reduce unnecessary x-rays by 25% to 50% or more with low likelihood of missing a fracture.

Boutis K, Grootendorst P, Willan A, et al: Effect of the Low Risk Ankle Rule on the frequency of radiography in children with ankle injuries, CMAJ 185:E731–738, 2013.

108. Should ankle sprains be casted?
No. If inversion ankle sprains are not complicated by a fracture or peroneal tendon dislocation, casting is not warranted. Randomized trials have shown that casts have no benefit over early immobilization with functional removable braces, and in fact, complete immobilization may actually delay rehabilitation.
109. What is the most significant mistake made during the evaluation of knee pain?
Failure to evaluate the hip as a source of the pain. Hip pathology frequently masquerades as knee or distal thigh pain (e.g., Perthes’ disease, slipped capital femoral epiphysis). More than one knee has undergone a diagnostic arthroscopy for hip pathology.

110. In acute injury, what injuries typically cause bleeding into the knee joint? Acute hemarthrosis will occur when there is an injury to an intra-articular structure. Injuries outside the knee joint capsule cannot cause bleeding into the joint. Injuries commonly associated with a hemarthrosis include:
• Rupture of the anterior or posterior cruciate ligaments
• Peripheral meniscal tears
• Intra-articular fractures (such as avulsion of the tibial spine)
• Major disruption or tear in the joint capsule
111. A 5-year-old boy with a painless swelling in the back of his knee has what likely condition?
Popliteal cyst. Also called Baker cysts, these occur more frequently in boys, are usually found on the medial side of the popliteal fossa, and are painless. In children, the cysts are rarely associated with intra-articular pathology. The mass should transilluminate on physical exam, confirming the fluid-filled nature of the lesion. The natural history is for the cyst to disappear spontaneously after 6 to
24 months. Surgery is not required except in extraordinary circumstances such as unremitting pain. Atypical findings (e.g., tenderness, firmness, history of rapid enlargement, pain) are justification for further diagnostic evaluation.

Herman AM, Marzo JM: Popliteal cysts: a review, orthopaedics 37:e678–e684, 2014.

112. How does patellofemoral stress syndrome occur?
This major cause of chronic knee pain in teenagers results from malalignment of the extensor mechanism of the knee. It is most commonly seen as an “overuse” entity in sports that involve running and full-knee flexion (e.g., track, soccer). It has been inappropriately called chondromalacia patella, which is a specific pathologic diagnosis of an abnormal articular surface that occurs in a minority of these patients. The patella serves as the fulcrum on which the quadriceps extends the knee. The multiple muscle bellies of the quadriceps may act asymmetrically causing greater stress on the lateral aspect of the patella. This is particularly a problem for individuals with problems placing them at risk for patellar symptoms including: femoral anteversion, external tibial torsion, high (alta) patella, abnormally developed quadriceps, excessive flattening of the trochlear groove, or an increased Q angle. Treatment consists of ice, rest, nonsteroidal anti-inflammatory drugs, quadriceps strengthening, hamstring stretching, and possibly patellar-stabilizing braces.
113. What is the Q angle? This angle describes the lines of force acting on the patella. The angle is formed by the intersection of a line drawn from the anterior-superior iliac spine to the patella, and a line from the patella to the tibial tubercle. For teenage males, the average Q angle is 14 degrees, and, for females, it is 17 degrees. Angles of >20 degrees create a bowstringing effect, which places a lateral stress on the patella and
predisposes individuals (particularly runners) to chronic knee pain.

SPINAL DISORDERS

KEY POINTS: SCOLIOSIS
1. Scoliosis of >10 degrees is relatively common (1% to 2%), but progression to ≤25 degrees and the need for treatment is rare.
2. Bracing does not permanently correct scoliosis, but it can prevent progression.
3. Establishing the maturity level of the skeleton is important because the risk of progression is increased with immaturity.
4. In adolescents, progressive curves are seven times more likely to appear in girls than in boys.
5. All scoliosis is not idiopathic: assess for limb-length discrepancy, congenital anomalies, and neurologic abnormalities, especially reflexes.

114. What are the different forms scoliosis?
Scoliosis is a lateral curvature of the spine (i.e., coronal plane deformity) that has several general causes. The most common form is idiopathic scoliosis that arises in otherwise

normal children for reasons that are not fully understood, but there is an underlying genetic cause. Idiopathic scoliosis is subdivided according to age at which the disease is diagnosed. Previously, three age groups were considered, but most now split idiopathic scoliosis into two groups:
early-onset (< 9 years) and adolescent (> 10 years). Congenital scoliosis occurs when there is a problem with the way the vertebrae form during embryogenesis. This form of scoliosis may be
associated with anomalies of the cardiac and renal systems, which are developing at the same time. Neurogenic scoliosis is associated with a variety of spastic and paralytic neuromuscular diseases such as cerebral palsy, muscular dystrophy, and myelomeningocele. Finally there are miscellaneous, typically syndromic, causes of scoliosis that can be associated with connective tissue disorders like Marfan and Ehlers-Danlos syndromes. Scoliosis is also seen in increased rates in children who underwent major abdominal or thoracic surgery in infancy (such as open heart surgery or congenital diaphragmatic hernia repair). Scoliosis has been reported after ligation of
a patent ductus arteriosus.

Konieczny MR, Senyurt H, Krauspe R: Epidemiology of adolescent idiopathic scoliosis, J Child Orthop 7:3–9, 2013. National Scoliosis Foundation: www.scoliosis.org. Accessed on Nov. 24, 2014.

115. Is scoliosis more common in boys or girls?
It depends on the age and the cause of the scoliosis. For idiopathic scoliosis seen in infancy, males outnumber females by a 3:2 margin. As age increases, females catch up and by adolescence, females are five to seven times more likely than males to have scoliosis.

Weinstein SL, Dolan LA, Wright JG, et al: Effects of bracing in adolescents with idiopathic scoliosis, N Engl J Med
369:1512–1521, 2013.

116. How likely is the progression of scoliosis?
Idiopathic scoliosis, characterized by a lateral curvature of the spine with a Cobb angle (see question
120) of 10 degrees or more is believed to occur in about 3% of children younger than 16 years of age. Only 0.3% to 0.5% will have progression of curves that will require treatment.

117. What are the risk factors for progression of idiopathic scoliosis?
Idiopathic scoliosis is a growth phenomenon, and the rate of progression of the curve is proportional to the rate of growth. This is why many curves become clinically apparent in adolescence just after the growth spurt. Therefore, the risk of progression is greater in younger children (who have more growth remaining) and the larger the curve, the more likely it is to progress. Most other
risk factors for progression are a surrogate for growth remaining such as skeletal age and menarchal status.

Hresko MT: Idiopathic scoliosis in adolescents, N Engl J Med 368:834–841, 2013.

118. How is screening for spinal deformity performed? The child should be undressed or dressed only in underwear with a gown open at the back. The child is asked to bend forward while standing and the contour of the back is examined from behind and the side. This exam is then repeated with the child sitting. The following signs can suggest scoliosis:
• Shoulder or scapular asymmetry
• Asymmetry of paraspinal muscles or rib cage (the so-called rib hump) in the thoracic spine noted on forward bending (>0.5 cm in lumbar region and >1.0 cm in thoracic region; a scoliometer may be used for this determination)
• Sagittal plane deformity such as increased kyphosis when viewed from the side
• Waist-crease asymmetry that does not disappear when sitting (many waist-crease asymmetries are the result of leg-length discrepancies). This finding is very helpful in obese patients whose paraspinal prominence may be obscured by their subcutaneous adipose tissue.
119. What constitutes an abnormal scoliometer measurement?
The scoliometer (also called an inclinometer) is a type of protractor used to measure the vertebral rotation and rib prominence that is seen in scoliosis with the forward-bending test (Fig. 15-13). An angle of ≤5 degrees is usually insignificant while an angle of ≤7 degrees warrants

orthopedic referral and consideration of standing posteroanterior and lateral radiographs for more precise assessment of curvature. This is different from the measurement of the scoliosis made on radiographs, which is known as the Cobb angle. Although it can vary dramatically, the Cobb
angle is often about three times as large as the scoliometer measure. Usually orthopedists discuss the Cobb angle when describing scoliosis, and it is the Cobb angle that typically dictates treatment.

Figure 15-13. Use of scoliometer demonstrating 20 degrees of trunk rotation. (From Dormans JP: Pediatric Orthopaedics and Sports Medicine: The Requisites in Pediatrics. Philadelphia, 2004, ELSEVIER Mosby, p 150.)

120. How is scoliosis measured by the Cobb method?
This is the standard technique used to quantify scoliosis in posteroanterior radiographs. One line is drawn along the vertebra tilted the most at the top of the curve, and another is drawn at the bottom of the curve. The curvature is represented by angle “a,” which can be measured in two ways, as illustrated in Figure 15-14.

Figure 15-14. Measurement of the Cobb angle. (From Kaz DS, Math KR, Groskin SA, editors: Radiology Secrets. Philadelphia, 1998, Hanley & Belfus, p 321.)

121. How valuable are school-based screening programs for scoliosis?
This is controversial. Many states in the United States mandate school scoliosis screening. Experts in favor of these programs contend that reliable screening procedures exist and that early identification will lead to earlier nonoperative care and the prevention of progression and of the need for surgical intervention. Opponents argue that the low incidence of children requiring treatment, the low positive-predictive value of screening programs, and high numbers of children unnecessarily referred do not justify the programs.

Burton MS: Diagnosis and treatment of adolescent idiopathic scoliosis, Pediatr Ann 42: 224–228, 2013.
Richards BS, Vitale MG: Screening for idiopathic scoliosis in adolescents, J Bone Joint Surg Am, 90:195–198, 2008.

122. What is the natural history of untreated severe idiopathic scoliosis?
Untreated idiopathic scoliosis that is greater than 50 degrees at skeletal maturity is likely to continue to progress throughout life. The rate of progression tends to be slow, on the order of 1 degree per year, but over the expected lifetime of the patient that could be 60 or more degrees of progression. However, even with this progression, adolescent idiopathic scoliosis (AIS) is generally not a fatal disease and there is little excess mortality seen in the few long-term natural history studies. Only when curves are greater than 90 to 100 degrees is there a clinically important effect on cardiopulmonary function. Some studies have shown psychosocial problems related to the patient’s dissatisfaction with their appearance, but not all studies have reproduced this finding. Back pain may be increased in this population compared with age-matched norms, but there is no indication that surgery improves upon this.

Weinstein SL, Dolan LA, Spratt KF, et al: Health and function of patients with untreated idiopathic scoliosis: a 50-year natural history study, JAMA 289: 559–67, 2003.

123. When should surgery be considered for idiopathic scoliosis?
As seen in the natural history, idiopathic scoliosis continues to progress throughout life once
larger than 50 degrees, so this is usually the criterion for surgery in AIS.
124. What type of surgery is typically performed for scoliosis correction?
The surgery is usually a fusion procedure in which the vertebrae involved in the curve are instrumented with metal implants and connected to a rod to correct the curve, to balance the spine and to stabilize the bones to allow them to fuse together. Clearly, this eliminates motion and prevents growth in the operated segment of the spine. Most children with AIS are undergoing surgery in adolescence and as such do not have a lot of growth remaining.
The height gained by straightening the spine typically offsets any potential loss of growth from fusing those vertebrae.
125. Are the spines of young children fused as well?
Not anymore. Scoliosis in toddlers and young children is one of the most difficult problems seen in pediatric orthopedics. Originally, these curves were corrected and fused with the theory being that a short straight spine is better than a longer crooked one. However, long-term follow-up found that fusing spines before the age of 8 or 9 resulted in small thoraxes and limited lung development. The result was that many patients were dying from respiratory insufficiency
in early adulthood because their lungs were unable to keep up with the needs of their adult bodies.
126. So how are large curves in young children treated?
This is a challenging question with no good answer. Currently there are several options available—casting, bracing, or growing implants. We know that fusing small spines is a bad idea, so implants that stabilize the spine while still allowing it to grow (sort of an internal brace) have been used with some success for a couple of decades. Current generation “growing rods” attach to the ribs, spine, and/or pelvis. These rods need to be lengthened periodically to compensate for the growth that is occurring in the spine and to maintain the correction of the scoliosis.
In the United States, these rods until very recently have required multiple surgeries to be lengthened with high complication rates. However, some patients are candidates for a rod that can be lengthened in the office using a magnetically controlled gearing mechanism. This device, available

in Europe for several years but only since 2014 in the US, is not indicated for all patients, but has the promise to greatly reduce the number of surgeries for many patients.

Hickey BA, Towriss C, Baxter G, et al: Early experience of MAGEC magnetic growing rods in the treatment of early onset scoliosis, Eur Spine J 23S:S61–S65, 2014.
Akbarnia BA, Blakemore LC, Campbell RM Jr, et al: Approaches for the very young child with spinal deformity: what’s new and what works, Instr Course Lect; 59:407–424, 2010.

127. Are casts still used to treat scoliosis?
The first fusion procedure for scoliosis was performed about 100 years ago, and for decades casts were used to stabilize the spine for months until the fusion could take hold. The advent of metal implants obviated the need for casts, but casting has become popular again as a treatment for scoliosis in the VERY young. A derotational casting technique has proven quite effective for many patients and can even be curative in some cases. While no open surgery is involved, the casts do require traction under anesthesia, and thus they are performed in the operating room.

Sanders JO, D’Astous J, Fitzgerald M, et al: Derotational casting for progressive infantile scoliosis, J Pediatr Orthop
29:581–587, 2009.

128. Is bracing an effective treatment for scoliosis?
There has long been a history of bracing in the orthopedic literature, and the results of studies have been somewhat mixed. Furthermore, the quality of many of these studies has been low and many orthopedists were unsure if bracing was an effective treatment. However, a 2013 multi-center study funded by the NIH found dramatic improvements in children who were braced compared with unbraced controls. Patients in the study were 10 to 15 years of age, required Cobb angles between 20 and 40 degrees, and wore the brace for at least 18 hours daily with reassessment by x-rays every 6 months. This BrAIST (Bracing in Adolescent Idiopathic Scoliosis Trial) study is the first to prove the effectiveness of bracing in premenarchal adolescent girls.

Weinstein SL, Dolan LA, Wright JG, et al: Effects of bracing in adolescents with idiopathic scoliosis, N Engl J Med
369:1512–1521, 2013.

129. What diagnosis should you consider in a teenage male with very poor posture that is not flexible?
Scheuermann kyphosis. This is a wedge-shaped deformity of the vertebral bodies of unclear etiology that causes juvenile kyphosis (abnormally large dorsal thoracic or lumber curves). Common in teenagers, it is distinguished from simple poor posture (“postural round-back deformity”) by its sharp angulation and inability to correct by having the patient stand up straight or lie on top of a bolster. X-ray studies reveal anterior vertebral body wedging and irregular erosions of the vertebral endplate. Treatment consists of exercise; bracing; and rarely, surgical correction (for severe, painful deformities).

130. What is the difference between spondylolysis and spondylolisthesis?
Spondylolysis is a condition in which there is a defect in the pars interarticularis (vertebral arch) of a vertebra that is most common at L5. This can be a congenital problem but is commonly seen as a stress fracture in athletes who do a lot of hyperextension of the lower back (classically gymnasts and football offensive linemen). Spondylolisthesis is a condition (often resulting from spondylolysis) that is characterized by forward slippage of one vertebra on the lower vertebrae. Pain is the most common presenting symptom for both conditions. The etiology is unclear, but various theories relate it to hereditary factors, congenital predisposition, trauma, posture, growth, and biomechanical factors.
Treatment includes watchful waiting, limitation of activity, exercise therapy, bracing, casting, and surgery, depending on the patient’s age, the magnitude of the slippage, the extent of pain, and the predicted likelihood of progression of the deformity.

Foreman P, Griessenauer CJ, Watanabe K, et al: L5 spondylolysis/spondylolisthesis: a comprehensive review with an anatomic focus, Childs NERV Syst 29:209–216, 2013.

SPORTS MEDICINE
131. A 12-year-old baseball player presents complaining of elbow pain. What diagnosis do you need to consider?
Little league elbow, an apophysitis of the medial epicondyle of the elbow, is a tension injury to the growth plate seen in pitchers’ (and other throwers’) elbows. Treatment includes rest and avoiding all throwing activities for a minimum of 4 to 6 weeks, followed by gradual resumption of throwing under the close guidance of a therapist and/or coach.

132. Which is worse for a baseball pitcher’s elbow: throwing curveballs or fastballs?
Conventional wisdom has held that curveballs are more stressful on the thrower’s elbow than fastballs. There are recommendations that curveballs not be thrown until an athlete is approaching skeletal maturity, which is around 14 years of age. However, recent research has found that the amount of mechanical stress on an elbow is not different when throwing a curveball or fastball. There may be other reasons to limit or delay throwing curveballs in younger athletes, but increased stress at the elbow does not seem to be one of them.

Nissen CW, Westwell M, Ounpuu S, et al: A biomechanical comparison of the fastball and curveball in adolescent baseball pitchers, Am J Sports Med 37:1492–1498, 2009.

133. How can elbow and shoulder injuries be prevented in pitchers?
The use of pitch counts to protect the arms of throwers at all levels of baseball from little league to the majors has come into the spotlight in recent years. There is evidence showing that pitch count is more important than the type of pitch thrown in protecting the elbow. Little league baseball has standardized the number of pitches allowed and the amount of rest mandated between pitching days.

Tjoumakaris FP, Pepe MD, Bernstein J: Eminence-based medicine versus evidence-based medicine: it’s okay for 12-year-old pitchers to throw curveballs; it’s the pitch count that matters, Phys Sportsmed 40:83–86, 2012.

134. Do meniscal tears occur in younger children?
Meniscal tears rarely occur before the age of 12 years. An exception is a patient with a discoid meniscus, which is a congenitally abnormal meniscus shaped like a hockey puck instead of the normal “C” appearance. Because there is meniscus in the weight-bearing portion of the knee (and the meniscus is not designed for this), all eventually tear and become symptomatic.
Meniscal tears in children not associated with a discoid meniscus are typically associated with significant injuries. Be sure to look for an associated injury to the anterior cruciate ligament.

135. If a ninth-grade soccer player with knee swelling “felt a pop” while scoring a goal, what are three possible diagnoses?
A pop or snap sensation in the setting of acute knee injury is usually associated with the following:
• Anterior cruciate ligament injury
• Meniscal injury
• Patellar subluxation

136. How is meniscal integrity assessed on examination?
Apley compression and McMurray test. The Apley test involves compression with pain in the knee suggesting injury. The McMurray test assesses lateral and medial tears by applying valgus stress/internal rotation and varus stress/external rotation, respectively, while feeling for pops/clicks and tenderness over the joint line, which, if present, could indicate injury (Fig. 15-15).

Apley compression test

McMurray test
Figure 15-15. Apley compression test is performed with the patient prone and the examiner’s knee over the patient’s posterior thigh. The tibia is externally rotated while a downward compressive force is applied over the tibia. The McMurray test is performed with the patient supine and the examiner standing on the side of the affected knee. (From Kleigman RM, Stanton BF, Schor NF, et al: Nelson Textbook of Pediatrics, ed 19. Philadelphia, 2011, ELSEVIER Saunders, p 2415.)

137. What is the typical mechanism for an anterior cruciate ligament (ACL) tear? The ACL sits in the knee joint and prevents the tibia from subluxing anteriorly out from under the femur. This ligament is under stress when weight is applied to a slightly flexed knee. When rotation and a valgus stress (a force pushing the knee toward the midline) are applied to the knee at the same time, the ligament is most susceptible to tearing. This combination of forces typically occurs when an athlete lands on the leg and tries to change direction.
138. How is ACL stability tested on examination?
Anterior drawer test and Lachman test. Both assess any possible abnormal forward movement of the tibia with the thigh/femur and foot stabilized. Excessive movement, compared with the opposite knee, suggests ACL injury (Fig. 15-16).
139. Why are girls and young women more susceptible to ACL tears than their male counterparts?
Rates of ACL tears in females are 3 to 8 times higher than in males. Suspected reasons include:
(1) anatomic factors, such as a narrower intercondylar notch in the knee and a wider pelvis than males; (2) biochemical factors, such as increased estrogen, which makes ligaments more elastic; and (3) neuromuscular factors in the way women activate muscles during jumping and landing. Researchers from Oregon have described additional risk factors that include chronic fatigue (three

Anterior drawer test Lachman test
Figure 15-16. Anterior drawer test is performed with the patient supine and the knee in 90 degrees of flexion. The Lachman test is conducted with the patient supine and the knee flexed 20 to 30 degrees. (From Kleigman RM, Stanton BF, Schor NF, et al: Nelson Textbook of Pediatrics, ed 19. Philadelphia, 2011, ELSEVIER Saunders, p 2415.)

times more likely in high school girls than boys) and dietary problems that range from poor nutritional intake to frank eating disorders.

Elliot DL, Goldberg L, Kuehl KS, et al: Young women’s anterior cruciate ligament injuries: an expanded model and prevention paradigm, Sports Med 40:367–376, 2010.

140. Are ACL tears treated differently in children, adolescents, and adults?
A resounding yes. Traditional ACL reconstruction procedures involve drilling a large tunnel across where the physis would be in the proximal tibia and distal femur. In children with open physes, the concern for growth arrest is great. Current recommendations are generally for using a physeal-sparing technique in prepubescent children, which is not as stable as traditional techniques and technically more difficult to perform. For younger adolescents, a transphyseal reconstruction is permitted, but the graft is entirely soft tissue and the sutures or screws used to stabilize the graft are placed far from the growth plate. In older adolescents, a standard trans-physeal technique is used, although no bone is placed across the growth plate (a technique sometimes used in adults).

Vavken P, Murray MM: Treating anterior cruciate ligament tears in skeletally immature patients, Arthroscopy
27:704–716, 2011.
Finlayson CJ, Nasreddine A, Kocher MS: Current concepts of diagnosis and management of ACL injuries in skeletally immature athletes, Phys Sportsmed 38:90–101, 2010.

141. Are there ways to prevent ACL tears? Most ACL tears are a result of noncontact plays (e.g., landing a jump or making a cut on the field, rather than being tackled or hit). The number of prevention programs has exploded across the country in recent years, typically involving neuromuscular exercises to retrain athletes regarding the best way to jump, land, and cut. These studies have often been very successful. A recent meta-analysis showed that on average these programs reduced ACL tears 50% in women and up to 80% in men.

Sadoghi P, von Keudell A, Vavken P: Effectiveness of anterior cruciate ligament injury prevention training programs, J Bone Joint Surg Am 94:769–776, 2012.

142. A teenager has chronic knee pain, swelling, and occasional “locking” of the knee joint, and his x-ray reveals increased density and fragmentation at the weight- bearing surface of the medial femoral condyle. What condition does he likely have?
Osteochondritis dissecans. In this disease, there is focal necrosis of a region of subchondral bone, typically in the lateral half of the medial femoral condyle. The cause is unknown, but

antecedent trauma is common and children (usually boys) with this condition are typically very active. These cases present with activity-related pain; locking, buckling, and stiffness may be seen as well. A plain radiograph can reveal the diagnosis, but an MRI is more sensitive when the clinical suspicion is high and radiographic findings are equivocal. Extended immobilization and activity restriction is the primary treatment in skeletally immature patients who have a favorable natural history. The lesions typically heal without surgery. For older adolescents and skeletally mature individuals, surgery is frequently required to stabilize the lesion and encourage healing. If the fragment does not heal, it may detach and become a loose body. This is a major problem
because the lost articular cartilage cannot be replaced and the risk for arthritis is high.
143. What is the most likely diagnosis if a 12-year-old basketball player has painful swelling below both knees?
Osgood-Schlatter disease. This is a traction apophysitis and results from repetitive stress (pull of the patellar tendon) on the tibial tubercle, which is connected to the tibial shaft through a cartilaginous plate. The cartilage is unable to handle the tensile forces created by the quadriceps muscle, and it hypertrophies and becomes inflamed. This process often occurs around the time of the adolescent growth spurt and is related to the level of physical activity. Physical examination reveals tenderness to palpation and a very prominent tibial tubercle. The pain is exacerbated with resisted knee extension.
Appropriate clinical management includes the judicious use of anti-inflammatory medications, restricted activities, quadriceps stretching and strengthening, and cross training. The condition is usually self-limited and resolves with skeletal maturity, although the bump remains.
Immobilization, which may lead to diffuse atrophy, is rarely necessary.
144. What is the likely diagnosis in a fifth-grade football player with heel pain and a positive “squeeze test”?
Sever disease, or apophysitis of the calcaneus. Caused by traction on the calcaneus at the insertion sites of the gastrocnemius-soleus muscles, microavulsions occur where bone meets cartilage. Pain is reproduced with compression of the medial and lateral aspects of the heel (the “squeeze test”). Treatment involves Achilles stretching, viscoelastic heel cups, and nonsteroidal anti-inflammatory drugs. Failure to improve suggests a possible calcaneal stress fracture, and immobilization may be required.

Soprano JV, Fuchs SM: Common overuse injuries in the pediatric and adolescent athlete, Clin Pediatr Emerg Med 8, 8–11, 2007.

145. Which sports injuries are the most common in school-age children and adolescents?
Some 75% of injuries in school-age children involve the lower extremities, and a majority of injuries to the knee and ankle are reinjuries as a result of incomplete healing from a previous problem. Contusions and sprains are the most common types of injury, with fractures and dislocations accounting for an additional 10% to 20%. Cranial injuries are the most common cause of sports fatality.
Adolescent boys who participate in contact team sports, particularly football and wrestling, are at the highest risk for injuries. Among girls, softball and gymnastics have the highest injury rate.
Only 10% of sports injuries are caused by an opponent; most injuries are caused by stumbling, falling, or misstepping. The latter finding suggests that improving intrinsic factors (e.g., raising the level of physical fitness, avoiding overuse, and strengthening joint stability) may be more important for the prevention of injuries than external factors (e.g., rule changes, equipment).
146. What are the definitions of concussion and postconcussion syndrome?
In 2004, the Second International Conference on Concussion in Sports defined a sports concussion as a complex physiological process following head trauma resulting in rapid onset of short-lived functional impairment, though in some cases associated with prolonged post-concussive symptoms, and typically associated with a normal CT scan. Postconcussion syndrome has been defined as the persistence beyond 7 to 10 days of the injury of any one of the following symptoms not present before injury: headaches, easy fatigability, sleep disturbances, dizziness, irritability, aggressiveness,

anxiety, depression, missed work, relationship troubles, personality change, trouble with simple math, and trouble with short-term memory.

Eisenberg MA, Meehan WP III, Mannix R: Duration and course of post-concussive symptoms, Pediatrics
133:999–1006, 2014.
ME, Walter KD, and the Council on Sports Medicine and Fitness: Clinical report—sport-related concussion in children and adolescents, Pediatrics 126:597–615, 2010.

147. What is the value of “brain rest” in the treatment of concussion?
COGNITIVE rest was proposed in 2004 based on the theory that activities that require concentration and attention may exacerbate the symptoms of concussion and thus delay recovery. Reduction of activities such as reading, text messaging, video game playing, computer use, and performing schoolwork has been urged by some as vital in concussion management. The underlying theory is that concussion results in a cerebral metabolic disruption with a decreased supply of adenosine triphosphate (ATP). Instituting cognitive rest conserves ATP supplies for injury recovery. Although the cognitive rest concept has been subject to debate, an increasing number of studies support its role as a tool in the management of concussions.

Brown NJ, Mannix RC, O’Brien MJ, et al: Effect of cognitive activity level on duration of post-concussion symptoms,
Pediatrics 133:e299–e304, 2014.
Halstead ME, McAvoy K, Devore CD, et al: Returning to learning following a concussion, Pediatrics 132: 948–957, 2013.

148. When should an athlete who has suffered a concussion be allowed to return to play?
No athlete should be allowed to return to the playing field on the day of the concussion nor thereafter if they are symptomatic at rest or with exertion. Although most overt symptoms will resolve within 1 week, younger athletes may require a longer recovery period for full cognitive function. Thus, a more conservative approach is used for pediatric and adolescent patients compared with adults. Graded return-to-play protocols with escalating exercises are recommended with a system in place to monitor symptoms and cognitive function. Postinjury neuropsychological testing (such as ImPACT testing) is often used as a guide to return, especially if preinjury testing
is available for comparison.

Heads Up to Clinicians: Concussion Training: www.cdc.gov/concussion/headsup/return_to_play.html. Accessed on Nov. 24, 2014.

Acknowledgments
The editors gratefully acknowledge contributions by Drs. Francis Y. Lee, John P. Dormans, Richard S. Davidson, Mark Magnusson, David P. Roye, and Joshua E. Hyman that were retained from the first four editions of Pediatric Secrets.

BONUS QUESTIONS
149. Are stretching exercises helpful for congenital muscular torticollis?
Yes. Studies have shown that management with manual stretching—particularly when initiated at an early age—significantly reduces the need for surgical correction.

Cheng JC, Wong MW, Tang SP, et al: Clinical determinants of the outcome of manual stretching in the treatment of congenital muscular torticollis in infants. A prospective study of eight hundred and twenty-one cases, J Bone Joint Surg 83:679–687, 2001.

150. What advice should be given to a parent about buying shoes for a toddler?
The best shoe is one that simulates the barefoot:
• The shoe should easily flex.
• The bottom of the shoe should be flat. Heels should be avoided because they tend to force the foot forward and cramp the toes.
• The shoe should be foot-shaped and generously fitted. The toe box should be wide and high to properly accommodate the toddler’s pudgy feet.
151. Which conditions are associated with coxa vara?
Coxa VARA is a condition of a decreased femur shaft–neck angle. The three most common associations are developmental coxa vara, avascular necrosis of the femoral head, and cleidocranial dysostosis.
152. How do the features of osteomyelitis in the neonate differ from those seen in the older child and adult?
• Multiple foci of infection are frequently seen.
• Septic arthritis is a frequent association, probably reflecting the spread of infection via blood vessels penetrating the epiphyseal plates.
• The pathogens causing neonatal osteomyelitis are the same as those responsible for sepsis neonatorum.
153. What predisposes a child or teenager to recurrent dislocation of the patella?
• Problems with alignment: Genu valgum, laterally displaced tibial tubercle, patella alta
• Developmental problems: Hypoplasia of the lateral femoral condyle, vastus medialis (VMO) insufficiency, abnormal attachment of the iliotibial tract
• Generalized ligamentous laxity: Down syndrome, Ehlers-Danlos syndrome, Marfan syndrome, Turner syndrome
154. Is there a genetic test for scoliosis?
Yes, but not one that works yet. A genetic test developed several years ago held promise to quantify the risk of progression for idiopathic scoliosis, but recently the effectiveness of this test in the real world was found to be suboptimal. Consistent genetic associations with idiopathic scoliosis are currently lacking. However, many research efforts continue looking for ways to genetically evaluate a patient’s risk for developing significant scoliosis because this is the
future of the field.