FREE Orthopedics MCQS 2022 1951.-2000.

1951. (1091) Q5-1451:

The timing of maximal progression of idiopathic scoliosis is most closely correlated with:

1) C hronological age

3) Peak height velocity

2) Skeletal age

5) Tanner stage

4) Risser sign

The cause of scoliosis or its progression is still not known. However, the timing of the progression is most closely correlated with the peak velocity of growth. The other factors are more weakly correlated: a chronological or skeletal age of 10 to 12 years, Risser sign of 0, or Tanner sign of 0 to 1.

■Correct Answer:Peak height velocity

1952. (1092) Q5-1452:

Which of the following events typically occurs first in adolescent girls:

1) Risser sign turning to 1

3) Menarche

2) Peak height velocity

5) Tanner sign of 3

4) Skeletal maturity

Typically, the peak height velocity is the first of these events to occur in adolescent girls. Skeletal maturity is the last event to occur.

■Correct Answer:Peak height velocity

1953. (1093) Q5-1453:

A 15-year-old with idiopathic scoliosis develops a temperature of 39.5° C 8 days after posterior spinal fusion with instrumentation. Blood and urine cultures show no growth, and chest X-ray is normal. Your next step should be which of the following:

1) Begin intravenous cephalosporin treatment

3) Aspirate the wound for culture

2) Begin intravenous vancomycin treatment

5) Debride the wound and remove the bone graft

4) Debride the wound and remove the instrumentation

There is a significant likelihood of a deep wound infection, although other possibilities exist, including superficial wound infection, atelectasis, and drug-related fever. Therefore, confirmation of the diagnosis is the next step. The wound should be aspirated for culture next. If infection is confirmed, the wound should be opened and debrided.

■Correct Answer:Aspirate the wound for culture

1954. (1094) Q5-1454:

Nine days after surgery, a 16-year-old boy with idiopathic scoliosis has a temperature of 39.5° C . Wound aspiration reveals gram-positive cocci in clusters. Your next step in management is:

1) Begin intravenous cephalosporin and monitor the response

3) Begin hyperbaric oxygen and intravenous antibiotics

2) Begin intravenous vancomycin and monitor the response

5) Open and debride the wound, and remove the instrumentation

4) Open and debride the wound, leaving the instrumentation in place

Open debridement is the treatment of choice if an early deep wound infection is confirmed after spinal fusion. The instrumentation is left in place to stabilize the wound and promote fusion. The wound is closed as long as it can be cleaned up adequately during surgery, and muscle has a healthy appearance. If this cannot be achieved or if several debridements fail, the wound may be left open.

■Correct Answer:Open and debride the wound, leaving the instrumentation in place

1955. (1095) Q5-1455:

A thoracic curve of more than 50° due to an idiopathic adolescent scoliosis curve has an increased risk of causing all except which of the following consequences in adulthood, when compared to the general population:

1) Restrictive lung disease

3) Back pain

2) Obstructive lung disease

5) Increase in curvature

4) Less positive body image

Idiopathic adolescent scoliosis is likely to progress in adulthood if it exceeds 50°. The rate of progression in adults is slower than during adolescence; about 1° per year. Nevertheless, it is likely to have some effect on pulmonary function later during adulthood. The effect is one of restrictive rather than obstructive lung disease. There is an increase in the risk of back pain, although it is rarely disabling. Patients with idiopathic scoliosis as a group have a more negative body image, although it is not a serious life impairment. In all of these parameters, there are individual exceptions.

■Correct Answer:Obstructive lung disease

1956. (1096) Q5-1456:

A 13-year-old girl with idiopathic adolescent scoliosis has a 32° right thoracolumbar curve. Her Risser sign is 1. Her curve measured 29° 4 months ago. You recommend:

1) Observing until the curve reaches 34°

3) Physical therapy to control the curve

2) Ordering a magnetic resonance image of the spine

5) A thoracolumbosacral orthosis

4) Electrical stimulation to the paraspinal muscles

Idiopathic scoliosis in skeletally immature patients should be braced if it is greater than 30° and significant growth remains (estimated by a Risser sign of 0, 1, or 2). Studies have shown that patients with idiopathic scoliosis without atypical findings do not need magnetic resonance imaging. Physical therapy and electrical stimulation have been shown not to have any effect on the progression of idiopathic scoliosis.

■Correct Answer:A thoracolumbosacral orthosis

1957. (1097) Q5-1457:

Which of the following factors are not related to the success of brace treatment for idiopathic scoliosis?

1) C urve size at start of treatment

3) Number of hours worn

2) C urve correction in brace

5) Positive family history of scoliosis

4) Gender

A lower chance of curve control with brace treatment has been shown with curves greater than 40°, correction of less than 50% in brace, brace worn fewer than 16 hours per day, or male gender. Positive family history has not been shown to be related to curve progression or chance of control.

■Correct Answer:Positive family history of scoliosis

1958. (1098) Q5-1458:

A 12-year-old patient has a rigid, 135° scoliosis. Gradually increasing halo-gravity traction is planned in correcting the curve. The maximum weight that should be used is:

1) 15% of body weight

3) 25% of body weight

2) 20% of body weight

5) 35% to 45% of body weight

4) 30% of body weight

Halo-gravity traction is a safe and effective means of gradually correcting large curves. It allows balanced force application and continuous neurological monitoring. C ranial and peripheral nerves should be monitored. The weight can be increased gradually up to 35% to 45% of body weight, as documented in published series.

■Correct Answer:35% to 45% of body weight

1959. (1099) Q5-1459:

In evaluating infants for Blount disease, which diagnostic parameter allows correct classification of the greatest number of children:

1) Langenskjold rating

3) Tibial metaphyseal-diaphyseal  (M-D) angle

2) Tibiofemoral angle

5) Femoral intercondylar distance divided by height

4) Femoral M-D angle divided by tibial M-D angle

The tibial metaphyseal-diaphyseal  (M-D) angle, no matter what threshold is set, has a significant number of false-positives or false-negatives. Using the ratio of femoral to tibial M-D angle improves diagnostic accuracy significantly. The Langenskjold rating, tibiofemoral angle, and intercondylar distances, although conceptually important, have low diagnostic accuracy for an individual patient.

■Correct Answer:Femoral M-D angle divided by tibial M-D angle

1960. (1100) Q5-1460:

Which of the following statements best characterizes a Dega osteotomy as a distinct osteotomy from a Salter osteotomy:

1) The Dega osteotomy is stabilized by threaded pins.

3) The Salter osteotomy hinges upon the triradiate cartilage.

2) The Dega osteotomy lengthens the ipsilateral limb.

5) The Dega osteotomy should only be done after triradiate cartilage closure.

4) The Dega osteotomy hinges upon the medial pelvic cortex.

The Dega osteotomy, originally described in Poland in 1964, is an incomplete transiliac osteotomy. The medial pelvic cortex is largely preserved, and the osteotomy hinges upon this point. Both osteotomies are best performed in young children, before triradiate cartilage closure. The Salter osteotomy is stabilized by pins, so the Dega needs no internal fixation. The Salter osteotomy lengthens the limb because it is a complete osteotomy.

■Correct Answer:The Dega osteotomy hinges upon the medial pelvic cortex.

1961. (1101) Q5-1461:

After the bone age of 15 years, boys will achieve the most growth from which of the following regions:

1) Distal femoral epiphysis

3) Distal tibial epiphysis

2) Proximal tibial epiphysis

5) Spine

4) Ilium and pelvis

After the age of 15 in boys (13 in girls), most of the growth (4.5 cm on average) occurs in the spine.

■Correct Answer:Spine

1962. (1102) Q5-1462:

The most accurate way to monitor the motor tracts during spinal surgery is to stimulate which of the following regions:

1) Tibial nerve

3) Motor cortex

2) Peroneal nerve

5) Proximal spinal cord

4) Gastrocnemius

The most accurate way to monitor the motor tracts of the spinal cord is to stimulate the motor cortex. Stimulation at the level of the spinal cord conducts mainly antidromically through sensory pathways. Stimulation of the tibial and peroneal nerve is performed for monitoring sensory pathways only; these are an important indicator of spinal cord integrity but do not monitor the motor pathways per se. Stimulation of the gastrocnemius does not have any value for monitoring.

■Correct Answer:Motor cortex

1963. (1103) Q5-1463:

Which of the following most definitively makes the diagnosis of Sever disease:

1) Sclerosis of the calcaneal apophysis on x-ray

3) Tenderness over the Achilles tendon

2) Irregularity of the calcaneal apophysis

5) Limitation of subtalar motion

4) Tenderness over the calcaneal apophysis

There are no radiographic findings diagnostic of Sever disease. Sclerosis and irregularity are normal findings, although they are often mistakenly called evidence of disease. The diagnosis of Sever disease is made by tenderness over the calcaneal apophysis.

■Correct Answer:Tenderness over the calcaneal apophysis

1964. (1104) Q5-1464:

A 12-year-old boy comes to your office 2 weeks after a distal radius physeal fracture, which has been splinted in the emergency department. The epiphysis is displaced dorsally by 50%, and the articular surface has a dorsal tilt of 17°. You recommend:

1) C losed manipulation with sedation

3) Open reduction, internal fixation

2) C losed manipulation under anesthesia with relaxation

5) Percutaneous pin fixation in current position

4) C ast application and observation

Distal radial physeal fractures are common injuries. Reduction should be done gently and not repeated multiple times. Fractures presenting late like this one are difficult to manipulate atraumatically, but have good remodeling potential. Therefore, a cast should be applied to limit any further displacement, but no manipulation or operation is recommended.

■Correct Answer:C ast application and observation

1965. (1105) Q5-1465:

Which of the following lowers the chance of a good result from stretching of muscular torticollis in infants:

1) Palpable mass in the sternocleidomastoid muscle

3) Rotation to neutral

2) Age at presentation less than 1 month

5) High birth weight

4) Absence of plagiocephaly

Stretching produces good results in more than 90% of infants. Presence of a palpable mass in the sternomastoid predicts a lower success rate than absence of such a mass. The other factors are either positive or neutral.

■Correct Answer:Palpable mass in the sternocleidomastoid muscle

1966. (1106) Q5-1466:

A 14-year-old boy suffers a hip dislocation in a motor vehicle accident. It is reduced by closed means. The risk of avascular necrosis is:

1) Less than 5%

3) 20%

2) 10%

5) 50%

4) 40%

Avascular necrosis is a risk of traumatic hip dislocation. The risk is closest to 10%.

■Correct Answer:10%

1967. (1107) Q5-1467:

Which of the following statements is true of the King classification of idiopathic scoliosis:

1) It takes into account sagittal alignment of curves.

3) It classifies all possible curve patterns.

2) It defines structural and nonstructural curves.

5) It has more curve types than the Lenke system.

4) It has a lower interobserver reliability than the Lenke system.

The Lenke system is more comprehensive than the King system, for the latter considers the entire range or thoracolumbar and lumbar curve possibilities, as well as the sagittal plane. The Lenke system also appears to have a higher interobserver reliability.

■Correct Answer:It has a lower interobserver reliability than the Lenke system.

1968. (1108) Q5-1468:

The most common form of chondrodysplasia punctata is much more common in girls than in boys. Which of the following explains this:

1) Autosomal dominant inheritance

3) X-linked recessive inheritance

2) X-linked dominant inheritance

5) The imprinting phenomenon

4) Autosomal recessive inheritance

X-linked dominant inheritance would explain the preponderance of girls with this condition, because they have twice as great a chance of having an affected x-chromosome. One affected x-chromosome is sufficient to convey the disease in a dominant condition. The imprinting phenomenon refers to a condition that varies depending upon whether the mother or the father passed it on (as in Angelman versus Prader-Willi syndromes).

■Correct Answer:X-linked dominant inheritance

1969. (1109) Q5-1469:

A 9-year-old boy injures his elbow in a fall from a 12-foot height. Radiographs reveal a posterior dislocation of the elbow with a fracture of the medial epicondyle which is displaced. The ossification center is 5 mm in diameter. You recommend:

1) Open reduction internal fixation with a smooth pin

3) Open reduction and fixation with a suture

2) Open reduction internal fixation with a small screw

5) C losed reduction of the dislocation and application of a splint

4) Open reduction with excision of the fragment and suture of the medial collateral ligament

A recent long-term study has shown that open reduction of displaced medial epicondyle fractures does not yield superior results to closed treatment. This applies even when the elbow is initially dislocated. Excision of the epicondyle with suture of the ligament yields the highest incidence of late problems, such as flexion contractures and degenerative changes.

■Correct Answer:C losed reduction of the dislocation and application of a splint

1970. (1110) Q5-1470:

The most accurate and practical means of determining pregnancy status in adolescent females undergoing surgery is:

1) Self report

3) Serum HC G

2) Morning urine human chorionic gonadotropin (HC G)

5) Serum estrogen levels

4) Serum alpha fetoprotein

Anesthesia and surgery can be detrimental to a fetus, especially during the first trimester. Patient self-report is not accurate in many cases. Immunospot testing of the first morning urine for human chorionic gonadotropin is 99.4% sensitive and specific, rapid, and inexpensive. Serum HC G testing is less rapid and more expensive; therefore, not appropriate for surgical screening. The other tests are not used to ascertain pregnancy status.

■Correct Answer:Morning urine human chorionic gonadotropin (HC G)

1971. (1111) Q5-1471:

Which of the following is considered a critical element in surgically correcting posttraumatic elbow flexion contractures in adolescents:

1) Lengthening of the biceps muscle

3) Perioperative indomethacin

2) Lengthening of the triceps muscle

5) Postoperative continuous passive motion and physical therapy

4) Pre- or postoperative radiation

Bae and Waters have shown that adolescents with significant posttraumatic elbow flexion contractures can gain an average of 54Â

° of motion with surgical release. They believe postoperative physical therapy and continuous passive motion are considered critical to success of surgical release. Lengthening of the biceps or triceps is not recommended. Measures to prevent postoperative heterotopic ossification did not influence the outcome.

■Correct Answer:Postoperative continuous passive motion and physical therapy

1972. (1112) Q5-1472:

Which of the following statements is true concerning atlanto-occipital dislocations in children:

1) The dens-basion distance is greater than 10 mm.

3) The injury is not survivable.

2) The power ratio is greater than 1.0.

5) No single plain radiographic finding is always diagnostic.

4) Spinal cord injury always accompanies this dislocation.

Pediatric atlanto-occipital dislocation is increasing in frequency due to improved emergency care. Although the injuries are sometimes fatal and are often accompanied by severe spinal cord injury, this is not always the case. Although the dens-basion distance should be less than 10 mm and the power ratio should be less than 1 in normals, these are not always abnormal in children with such injuries. C linical and radiographic correlation, with computer tomography or magnetic resonance imaging if needed, are called for to maximize diagnosis.

■Correct Answer:No single plain radiographic finding is always diagnostic.

1973. (1113) Q5-1473:

Equinovarus positioning of the foot is normal during which stage of embryonic life:

1) No stage

3) Thirteenth to fifteenth week

2) Eighth to tenth week

5) Twentieth to twenty-third week

4) Seventeenth to nineteenth week

As the foot matures, it passes through a normal stage when it resembles a clubfoot in the eighth to tenth week. After this, the foot normally corrects itself.

■Correct Answer:Eighth to tenth week

1974. (1114) Q5-1474:

Which of the following is a similarity between congenital pseudarthrosis of the clavicle and congenital pseudarthrosis of the tibia:

1) Both are common in neurofibromatosis

3) Both have a low rate of union after treatment with autograft unless it is vascularized

2) Both are common in cleidocranial dysplasia

5) Both may present with tapered, atrophic bone ends at the pseudarthrosis

4) Both are more common on the left side

C ongenital pseudarthrosis of the clavicle and tibia may present in infants with a gap between two tapered, atrophic bone ends. However, they are dissimilar in other respects. Pseudarthrosis of the clavicle is seen almost exclusively on the right side, while that of the tibia is seen on either side. Pseudarthrosis of the clavicle may be seen in cleidocranial dysostosis, although tibial pseudarthrosis is not. Pseudarthrosis of the clavicle has a high rate of union with simple bone graft, while that of the tibia does not. One-half of patients with pseudarthrosis of the tibia have neurofibromatosis, while this is almost never seen in congenital pseudarthrosis of the clavicle.

■Correct Answer:Both may present with tapered, atrophic bone ends at the pseudarthrosis

1975. (1115) Q5-1475:

A 13-year-old boy has a left slipped capital femoral epiphysis which has displaced 75%. He is unable to bear weight on the limb. The other hip has no clinical or radiographic abnormalities. Your preferred treatment is which of the following:

1) Gentle reduction of the slip and fixation with a cannulated screw

3) C uneiform osteotomy

2) Hip spica cast

5) Free vascularized fibular grafting

4) Subtrochanteric osteotomy

This is an unstable slip. It has a much higher chance of avascular necrosis than a stable slip. Since the degree of the slip will increase the shear forces across the healing physis and decrease the function of the hip, some method of improving this is justified. Gentle reduction of the epiphysis, without forceful internal rotation, may increase the risk of avascular necrosis. Avascular necrosis is a significant risk in many series of cuneiform (metaphyseal; Fish) osteotomies. Subtrochanteric osteotomy is not justified in patients with an acute slip until it is healed. It has a high rate of chondrolysis. Free vascularized bone graft may be an option if avascular necrosis develops, but is not indicated at this time. A hip spica cast is also often followed by chondrolysis

and delayed epiphyseodesis.

■Correct Answer:Gentle reduction of the slip and fixation with a cannulated screw

1976. (1116) Q5-1476:

Of all slipped capital femoral epiphyses, which percentage is unstable:

1) 5%

3) 25%

2) 15%

5) 50%

4) 35%

Unstable slipped capital femoral epiphysis places the patient at a high risk of avascular necrosis (up to 47%). Fortunately, it comprises only about 5% of all slips.

■Correct Answer:5%

1977. (1117) Q5-1477:

The normal value for the hallux valgus angle is:

1) 0° to 5°

3) 10° to 20°

2) 5° to 10°

5) 30° to 40°

4) 20° to 30°

The angle between the first metatarsal and its proximal phalanx is normally one of mild (10° to 20°) valgus. It is not normal for it to be too straight. An increase in this angle beyond this value is often noted by the patient as a bunion.

■Correct Answer:10° to

20°

1978. (1118) Q5-1478:

A 13-year-old girl is seen in clinic for bunion. She is asymptomatic but has a hallux valgus angle of 29°, an intermetatarsal angle of 15°, and a medial prominence over the first metatarsal head. The family asks whether anything can be done to prevent future problems with the foot. You recommend:

1) Osteotomy of the first metatarsal base

3) Double osteotomy of the first metatarsal

2) Hemiepiphyseodesis of the medial physis of the first metatarsal

5) Shoe modifications if symptoms develop

4) Mitchell osteotomy

Bunions may often be treated conservatively, and it is impossible to predict which ones will later develop symptoms. Surgical reconstruction of bunions in adolescents has a higher rate of recurrence than in adults in many reported series. For all of these reasons, nonoperative treatment is preferred for asymptomatic patients.

■Correct Answer:Shoe modifications if symptoms develop

1979. (1119) Q5-1479:

Which of the following tendons is not usually contracted in a patient with untreated vertical talus:

1) Anterior tibialis

3) Peroneus brevis

2) Posterior tibialis

5) Achilles

4) Extensor digitorum longus

A vertical talus is a fixed dorsolateral dislocation of the talonavicular joint. The forefoot is in calcaneus and the hindfoot is in equinus. Therefore, all of the tendons listed except for the posterior tibialis are contracted.

■Correct Answer:Posterior tibialis

1980. (1120) Q5-1480:

A 9-year-old boy is seen because of pain medially, in the arch of the foot. His ankle dorsiflexion is limited to 10° with the knee extended. Radiograph shows an accessory navicular, which corresponds to the point of his tenderness. You recommend:

1) Excision of the accessory navicular

3) Evans procedure (lateral column lengthening)

2) Excision of the accessory navicular with advancement of the posterior tibialis tendon

5) Activity restriction, stretching, arch support

4) Tendoachilles lengthening

Accessory navicular is seen in 10% to 14% of normal children. Sometimes, it becomes symptomatic in juveniles or adolescents, but this usually resolves by skeletal maturity. C onservative treatment, such as activity restriction, arch support, and stretching the Achilles if tight, will usually alleviate symptoms.

■Correct Answer:Activity restriction, stretching, arch support

1981. (1121) Q5-1481:

Which of the following disorders is due to a defect in anterior horn cells:

1) C harcot-Marie-Tooth

3) Friedreichâs ataxia

2) Duchenne dystrophy

5) Rett syndrome

4) Spinal muscular atrophy

C harcot-Marie-Tooth disease is due to a defect in peripheral nerves; Duchenne muscular dystrophy is due to a defect in dystrophin, affecting the muscle cell membrane; Friedreich ataxia is a degeneration of the spinocerebellar tracts. Rett syndrome is due to a defect in MEC P-2 protein, affecting the brain. Only spinal muscular atrophy is due to a defect in anterior horn

cells.

■Correct Answer:Spinal muscular atrophy

1982. (4041) Q5-1482:

Becker muscular dystrophy is due to a defect in the gene for which of the following:

1) Dystrophin

3) Myelin

2) Sarcoglycan

5) Fibroblast growth factor receptor

4) Sulfate transport

Becker muscular dystrophy has a defect in the same gene as Duchenne muscular dystrophy, namely the protein dystrophin. The mutation in Becker dystrophy results in a truncated protein that retains some function, whereas the mutation in Duchenne dystrophy is different and results in an unstable protein, which is degraded quickly.

■Correct Answer:Dystrophin

1983. (1122) Q5-1483:

Which of the following muscles is first affected in facioscapulohumeral dystrophy:

1) Orbicularis oris

3) Deltoid

2) Serratus anterior

5) Infraspinatus

4) Supraspinatus

In facioscapulohumeral dystrophy, the facial muscles are affected first, commonly presenting with an inability to whistle. The serratus muscles and scapular stabilizers are affected next. The deltoid, supraspinatus, and infraspinatus are typically not affected in this disease.

■Correct Answer:Orbicularis oris

1984. (1123) Q5-1484:

Emery-Dreifuss muscular dystrophy is unique among the dystrophies because of the development of which deformity:

1) Neck extension contracture

3) Knee flexion

2) Hip abduction

5) Scoliosis

4) Equinus contracture

Emery-Dreifuss muscular dystrophy is an x-linked disorder of emerin, which is a cell-membrane protein. Symptoms and signs develop within the first decade in most cases. A unique deformity, neck extension contracture, develops, in addition to elbow flexion contractures and peroneal wasting. The other deformities listed above are common in many dystrophies.

■Correct Answer:Neck extension contracture

1985. (1124) Q5-1485:

Electrodiagnostic testing in myopathies typically shows all of the following except:

1) Low amplitude electromyogram (EMG) potentials

3) Normal nerve conduction velocity

2) Polyphasic EMG potentials

5) Fibrillation potentials

4) Decreased duration of EMG response

Electrodiagnostic testing in myopathy typically shows low amplitude, polyphasic EMG potentials with a decreased duration of response. Nerve conduction velocity is normal, in contrast to findings in neuropathies. Fibrillations are not typically seen; these are more characteristic of neuropathy.

■Correct Answer:Fibrillation potentials

1986. (1125) Q5-1486:

In which region is direct anatomical extension from the metaphysis of a long bone to the adjacent joint not anatomically possible in the child:

1) Shoulder

3) Hip

2) Elbow

5) Ankle

4) Knee

The metaphysis of the proximal humerus lies partially within the shoulder joint; similarly, that of the proximal radius lies within the elbow. The metaphysis of the proximal femur lies within the hip joint and that of the distal lateral tibia within the ankle joint. There is no intra-articular metaphysis about the knee, however.

■Correct Answer:Knee

1987. (1126) Q5-1487:

Which of the following skeletal dysplasias is not commonly associated with non-orthopedic complications:

1) McKusick metaphyseal chondrodysplasia

3) Morquio syndrome

2) Hurler syndrome

5) Multiple epiphyseal dysplasia

4) C hondroectodermal dysplasia

McKusick dysplasia is commonly associated with immune and gastrointestinal disorders. Hurler syndrome is associated with progressive mental retardation, hepatosplenomegaly, and cataracts. Morquio syndrome is associated with cardiorespiratory difficulties. C hondroectodermal dysplasia, or Ellis van C reveld syndrome, is associated with congenital heart disease. Multiple epiphyseal dysplasia, however, is not associated with systemic non-orthopaedic complications.

■Correct Answer:Multiple epiphyseal dysplasia

1988. (1127) Q5-1488:

Which of the following by itself is not an indication for surgery in a child with acute hematogenous osteomyelitis:

1) Fever higher than 38.5°

3) Presence of a sequestrum

2) Subperiosteal abscess

5) Adjacent septic arthritis

4) Intramedullary abscess

Surgery is indicated in situations in which antibiotics alone will not be curative, including subperiosteal abscess, sequestrum, intramedullary abscess, and adjacent septic arthritis. Fever alone is not an indication for surgery.

■Correct Answer:Fever higher than 38.5°

1989. (1128) Q5-1489:

Which of the following is not usually seen in chronic recurrent multifocal osteomyelitis:

1) Positive cultures for Staphylococcus epidermidis

3) Involvement of the spine, long bones, and feet

2) Gradual onset of symptoms

5) Improvement with nonsteroidal anti-inflammatory agents

4) Negative cultures

C hronic recurrent multifocal osteomyelitis is believed to be an idiopathic noninfectious inflammatory disease. It has gradual onset of symptoms, and sites most commonly involved are the spine, long bones, and feet. Nonsteroidal anti-inflammatory drugs typically improve symptoms. C ultures are negative.

■Correct Answer:Positive cultures for Staphylococcus epidermidis

1990. (1129) Q5-1490:

A 5-year-old child is bitten by a tick. Which of the following has been shown to aid in management:

1) Prompt tick removal

3) Immediate treatment with amoxicillin

2) Immediate treatment with doxycycline

5) Steroid administration

4) Prompt ELISA testing

Prompt tick removal is recommended because Lyme disease is more likely if the tick is attached for more than 24 hours. Immediate antibiotic administration is not recommended because the incidence of Lyme disease is low after any single tick bite and treatment is equally effective once the disease is diagnosed. Doxycycline is not recommended in children younger than 8

years old because of dental discoloration. Immediate testing for antibodies (ELISA) is not useful because antibodies do not rise for at least several weeks. Steroids are not recommended in this setting.

■Correct Answer:Prompt tick removal

1991. (1130) Q5-1491:

Which of the following measures has not been shown to decrease rates of injury in healthy children participating in recreational sports:

1) Knee braces during basketball and football

3) Helmets for bicyclists

2) Ankle braces in basketball

5) Break-away bases for baseball

4) Mouth guards for basketball

Knee braces have been shown not to reduce injury rates for children for children with sound knees. All other measures have been shown to reduce injury rates.

■Correct Answer:Knee braces during basketball and football

1992. (1131) Q5-1492:

Which recreational activity causes the most musculoskeletal injuries in children ages 5 to 14 in the United States:

1) Bicycles

3) Soccer

2) Football

5) Gymnastics

4) Trampolines

Bicycles are the leading cause of musculoskeletal injury in American children, with 415,000 injuries per year, followed by basketball, football, and roller sports.

■Correct Answer:Bicycles

1993. (1173) Q5-1538:

The effects of pediatric orthopedic conditions in later adulthood commonly determine treatment choices for children. At what threshold does limb length discrepancy increase the energy cost of walking in older adults:

1) 2 cm

3) 4 cm

2) 3 cm

5) No such effect has been proven at any discrepancy.

4) 5 cm

A limb length discrepancy of as little as 2 cm has shown to increase perceived exertion as well as oxygen consumption in older adults.

■Correct Answer:2 cm

1994. (1174) Q5-1539:

Anterior elbow release in children with cerebral palsy is likely to result in which of the following outcomes:

1) Decreased flexion posture during use

3) Increased use during bimanual activity

2) Decreased flexion contracture

5) Increased grip strength

4) Increased strength of elbow flexion

Anterior elbow release consists of lengthening of the lacertus fibrosus and the brachialis fascia. It may or may not include lengthening of the biceps tendon itself. Anterior elbow release effectively decreases the excessive flexion posture of the elbow during use, which one author has termed the âflexion posture angle.â It does not result in decreased (or increased) strength of elbow flexion if the biceps tendon is preserved. Unfortunately, increased use during bimanual activity and increased grip strength are usually not observed.

■Correct Answer:Decreased flexion posture during use

1995. (1175) Q5-1540:

Which of the following procedures is most likely to correct idiopathic toe walking with a single treatment:

1) Stretching program

3) Stretching cast

2) Ankle foot orthosis

5) Percutaneous tendoachilles lengthening

4) Botulinum toxin injection

Percutaneous tendoachilles lengthening is most likely to resolve idiopathic toe walking in a single treatment. The other methods have a higher likelihood of persistent toe walking.

■Correct Answer:Percutaneous tendoachilles lengthening

1996. (1176) Q5-1541:

C ore binding factor alpha 1 (C bfa1) is a transcription factor having which of the following effects:

1) C bfa1 induces cells to differentiate into osteoblasts.

3) C bfa1 inhibits endochondral ossification.

2) C bfa1 induces cells to differentiate into osteoclasts.

5) C bfa1 causes premature cell death.

4) C bfa1 impairs sulfation of proteoglycans.

C bfa1 is a transcription factor that causes cells to differentiate into osteoblasts. An abnormality in its gene causes cleidocranial dysplasia.

■Correct Answer:C bfa1 induces cells to differentiate into osteoblasts.

1997. (1177) Q5-1542:

Which of the following is found less often in children with lumbosacral agenesis as compared to controls:

1) C ervical spine anomalies

3) Hip dislocation

2) Maternal diabetes

5) Genu recurvatum

4) Spina bifida

Patients with lumbosacral agenesis often have knee flexion contractures as compared with controls. All of the other features listed are common in patients with lumbosacral agenesis.

■Correct Answer:Genu recurvatum

1998. (1178) Q5-1543:

Which of the following figures most closely approximates the prevalence of defects in the L5 pars interarticularis in a newborn:

1) Less than 1%

3) 5%

2) 3%

5) 15%

4) 10%

Pars interarticularis defects are not found in newborns, whereas the incidence is 5% in patients who are in the first grade. It remains close to this figure throughout later life.

■Correct Answer:Less than 1%

1999. (1179) Q5-1544:

Which of the following is the most common cause of low back pain in young athletes:

1) Thoracolumbar Scheuermann apophysitis

3) Slipped vertebral apophysis

2) Herniated nucleus pulposus

5) Avulsion of the spinous apophysis

4) Spondylolysis

Spondylolysis is the most common cause of back pain in young athletes, accounting for approximately 50% of cases. The other causes are significantly less common.

■Correct Answer:Spondylolysis

2000. (1180) Q5-1545:

A 7-year-old boy with cerebral palsy, total involvement type, has neuromuscular hip dysplasia. The migration index is 60%

without flattening. He has had pain in the groin for the past 6 months. Recommended treatment includes:

1) Adductor tenotomy

3) Proximal femoral resection

2) Adductor tenotomy and femoral osteotomy

5) Total hip arthroplasty

4) Hip arthrodesis

Pain in the spastic patient with subluxation without head deformity is most appropriately treated by reduction. Adductor tenotomy alone is not recommended when the hip subluxation exceeds 50% or the age is greater than 5 to 6 years. Femoral osteotomy should be added. Salvage procedures such as proximal femoral resection, arthrodesis, or arthroplasty are not indicated.

■Correct Answer:Adductor tenotomy and femoral osteotomy