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4. Pediatrics MCQs

Practice Set 78 of 334

This practice set contains high-yield board review questions covering key concepts in 4. Pediatrics. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 1541

Topic: 4. Pediatrics
A toddler is brought in by his parents for evaluation of gait problems. Birth history and neurologic examination are unremarkable. After evaluating femoral torsion, tibial torsion, and foot contour, the diagnosis is excessive internal tibial torsion. The parents should be advised to expect which of the following outcomes?
. Resolution by age 3 or 4 years without active treatment in most patients
. Resolution by age 8 or 9 years without active treatment in most patients
. Resolution with casting as the most effective treatment
. Resolution with bracing and shoe modification as the most effective treatment
. Resolution with surgery as the most effective treatment

Correct Answer & Explanation

. Resolution by age 3 or 4 years without active treatment in most patients

Explanation

DISCUSSION: Excessive internal tibial torsion is a common cause of intoeing in toddlers. In most children, this resolves spontaneously by 3 to 4 years of age. Intoeing in elementary age children is usually the result of excessive femoral anteversion. Studies have shown that active intervention (casting, splinting, and shoe modifications) has no demonstrable effect on the natural history or resolution of tibial torsion. Surgery is rarely indicated in adolescents with severe internal tibial torsion that has not resolved and is resulting in cosmetic and functional problems.

Question 1542

Topic: 4. Pediatrics

A Spanish speaking child sustained the injury seen in Figure A after a fall at school. He was casted in the emergency department without the assistance of an interpreter and advised to return to see an orthopaedic surgeon in 1 week. However, the family returns to the emergency department with the child 3 months later, still in the cast. What is the most likely reason the child did not attend the recommended orthopaedic follow-up visit.?

. The child is a victim of neglect
. The child had no symptoms of pain
. He was allowed to return to school wearing the cast
. Concerns of cost
. Follow-up instructions were not effectively communicated

Correct Answer & Explanation

. The child is a victim of neglect

Explanation

The most likely reason the child did not attend the recommended orthopaedic followup visit was a language barrier preventing effective communication of the intended follow-up instructions.Communication skills and cultural competence is a key element in good orthopaedic care. Poor communication can often lead to devastating outcomes. In this example, poor communication resulted in this patient being lost to follow-up. Language barriers must be accommodated and alternative methods of communication must be utilized.Levinson et al. examined how patients present their medical issues in clinical encounters and how physicians respond to these clues in routine primary care and surgical settings. They showed that good communication relies mostly on the physicians ability to identify patient clues within the clinical encounter. Poor communication between the physician tended to delay clinical visits, poor follow-up and unsatisfactory outcomes.Figure A is an AP radiograph of the elbow in a skeletally immature patient. Figure B is a lateral radiograph of the elbow with a posterior fat pad sign, suggestive of an occult fracture.Incorrect Answers:

Question 1543

Topic: 4. Pediatrics
Figures 20a and 20b show the sagittal and coronal T1-weighted MRI scans of a patient’s left knee. Abnormal findings include
. enchondroma of the proximal tibia.
. a bone bruise of the lateral femoral condyle.
. a tear of the lateral collateral ligament.
. a tear of the discoid lateral meniscus.
. a physeal fracture of the proximal femur.

Correct Answer & Explanation

. a tear of the discoid lateral meniscus.

Explanation

DISCUSSION: The MRI scans show meniscal tissue extending across the entire lateral compartment, revealing a discoid lateral meniscus. The increased signal within the lateral meniscal tissue indicates a tear. Discoid lateral menisci are congenital variants that often present with mechanical symptoms in adolescents. The other structures in the knee are normal.

Question 1544

Topic: 4. Pediatrics
The addition of which of the following food supplements may lead to a decrease in neural tube defects?
. Vitamin D-1,25
. Vitamin B-12
. Niacin
. Folic acid
. Thiamine

Correct Answer & Explanation

. Folic acid

Explanation

The use of folic acid in developed countries has led to a decrease in neural tube defects. The incidence of neural tube defects is increased in third-world countries.

Question 1545

Topic: Pediatric Hip
Figure 46 shows the radiograph of an obese 12-year-old boy who has had left hip pain for the past 3 months. What is the best course of action?
. Decreased activities and physical therapy
. Left hip reduction and internal fixation
. Left hip pinning in situ
. Bilateral hip pinning in situ
. Spica cast immobilization

Correct Answer & Explanation

. Left hip pinning in situ

Explanation

The patient has an obvious slipped capital femoral epiphysis of the left hip for which the recommended treatment is percutaneous pinning in situ. Development of a contralateral slip is less likely at this age; therefore, observation of the right hip is indicated because there is no general agreement regarding prophylactic fixation. Typically, there is no role for spica casting. Physical therapy is not indicated as a primary treatment, and reduction is contraindicated, as it has been associated with osteonecrosis.

Question 1546

Topic: 4. Pediatrics
Figure 29a shows the clinical photograph of a 26-year-old woman who has had the leg deformity since birth. She reports difficulty with walking and weight bearing and notes increased discomfort and swelling when the leg is dependent. She denies any history of trauma or family history of a similar disorder. Examination reveals a fixed equinovarus deformity of the foot but no evidence of a limb-length discrepancy. No other cutaneous findings or soft-tissue masses are noted. Sagittal and axial T1- and T2-weighted MRI scans are shown in Figures 29b and 29c. What is the most likely diagnosis?
. Poliomyelitis
. Neurofibromatosis (von Recklinghausen disease)
. Lymphangiomatosis
. Congenital band syndrome
. Chronic venous stasis disease

Correct Answer & Explanation

. Lymphangiomatosis

Explanation

Because the MRI scans show marked dilation and proliferation of lymphatic channels that completely involve all the leg muscles and the clinical photograph shows the severe swelling associated with this disease, the most likely diagnosis is lymphangiomatosis. Poliomyelitis affects the anterior horn cells and manifests as muscle atrophy. Neurofibromatosis can have a similar clinical appearance but usually is associated with other systemic and cutaneous findings. Congenital band syndrome results in amputated or shortened extremities. Chronic venous stasis disease usually is not associated with joint contractures, and typically it affects older individuals. Surgical excision is the only known treatment; this patient underwent an above-knee amputation.

Question 1547

Topic: 4. Pediatrics
A 4-year-old child was born with bilateral congenital radial clubhands. Which of the following associated conditions is a contraindication to centralization of the hands on the ulna?
. Congenital scoliosis
. Hypoplastic thumb
. Tracheoesophageal fistula
. Imperforate anus
. Lack of elbow flexion

Correct Answer & Explanation

. Lack of elbow flexion

Explanation

Patients born with bilateral radial clubhands may have difficulty getting their hands to their mouth. The centralization procedure would take away that ability if there is a lack of elbow flexion.

Question 1548

Topic: 4. Pediatrics
Among patients with adolescent idiopathic scoliosis, a thoracolumbosacral orthosis is most effective for which type of curve?
. Apex of the curve is at T3
. Apex of the curve is at T8
. Apex of the curve is at L1
. Apex of the curve is at L2

Correct Answer & Explanation

. Apex of the curve is at T8

Explanation

A thoracolumbosacral orthosis is most effective for bracing of curves when the apex is at T7 or below. Bracing is used for patients who are skeletally immature (Risser stage 0, 1, or 2), and it is recommended that the brace be worn 16 to 23 hours per day and continued until skeletal maturity or until the curve progresses to beyond 45 degrees, at which point bracing is no longer considered effective.

Question 1549

Topic: Pediatric Hip

A 40-year-old man has had hip pain with increased activity over the past year. Examination reveals restriction of motion and tenderness with combined hip flexion, adduction, and internal rotation. An AP radiograph is shown in Figure 34. What is the most likely diagnosis? Review Topic

. Developmental dysplasia of the hip
. Osteonecrosis
. Perthes disease
. Pseudogout
. Femoral acetabular impingement

Correct Answer & Explanation

. Developmental dysplasia of the hip

Explanation

Femoral acetabular impingement (FAI) is a pathologic entity leading to pain, reduced range of motion in flexion and internal rotation, and development of secondary arthritis of the hip. There are two types of FAI: cam impingement and pincher impingement. Cam impingement is seen when a nonspherical femoral head produces a cam effect when the prominent portion to the femoral head rotates into the joint. This mechanism produces shear forces that damage articular cartilage. Radiographs reveal early joint degeneration and flattening of the head neck junction (the so-called “pistol grip deformity”) as seen in this image. The pincher type of impingement involves abnormal contact between the femoral head neck junction and the acetabulum, in the presence of a spherical femoral head.

Question 1550

Topic: 4. Pediatrics
Figures 39a and 39b show the radiographs of an otherwise healthy 10-year-old boy who has had thigh pain and a limp for the past 9 months. Examination reveals that the left lower extremity is 1 cm shorter, with reduced flexion, abduction, and internal rotation on the left side. The patient is at the 50th percentile for height and the 90th percentile for weight. Serum studies will most likely show
. an elevated thyroid-stimulating hormone level.
. an elevated estrogen level.
. elevated blood urea nitrogen and creatinine levels.
. a growth hormone deficiency.
. normal laboratory values.

Correct Answer & Explanation

. normal laboratory values.

Explanation

The patient has a slipped capital femoral epiphysis (SCFE) at a younger than average age (average age 13.5 years for boys and 12.0 years for girls); therefore, an etiology that is not idiopathic must be considered. Hypothyroidism can result in a SCFE, but these children typically fall into the category of less than the 10th percentile for height. SCFE may develop in children with a growth hormone deficiency who have undergone hormonal replacement. Osteodystrophy caused by chronic renal failure may result in a SCFE, but the bone quality is markedly osteopenic on radiographs and the children are chronically ill with both low height and weight percentiles. An elevated estrogen level results in physeal closure and is protective to physeal slippage. Therefore, this child will most likely have normal laboratory values.

Question 1551

Topic: Pediatric Upper Extremity & Spine

A 13-year-old girl with adolescent idiopathic scoliosis is otherwise healthy with a normal neurologic examination and she began her menstrual cycle 3 months ago. Standing radiographs show a high left thoracic curve from T1-T6 that measures 29 degrees, a right thoracic curve from T7-L1 that measures 65 degrees, and a left lumbar curve from L1-L5 that measures 31 degrees, correcting to 12, 37, and 10 degrees, respectively, on bending films. Her Risser sign is 1. What is the most appropriate management? Review Topic

. Bracing
. Posterior spinal fusion of only the right thoracic curve
. Posterior spinal fusion from T2-L4
. Vertebral body stapling to halt progression of the curve
. Anterior and posterior spinal fusion

Correct Answer & Explanation

. Posterior spinal fusion of only the right thoracic curve

Explanation

The patient has typical adolescent idiopathic scoliosis with a right thoracic curve. This represents a Lenke-1B curve pattern; therefore, only treatment of the thoracic curve is required. The proximal thoracic and thoracolumbar curves are very flexible. The patient is Risser 1 and has just started her menstrual cycles; therefore, she is at significant risk for further curve progression. Bracing is not appropriate for a curve of this magnitude and will not halt the progression of this curve, nor will vertebral body stapling stop this curve. Vertebral body stapling is sometimes useful in small thoracic curves of less than 35 degrees and skeletally immature patients. Anterior and posterior spinal fusion is not required because the patient has no other risk factors, such as neurofibromatosis nor is she at risk for crankshaft. Anterior fusion is an option, but it is not listed.

Question 1552

Topic: 4. Pediatrics

-A 10-year-old boy sustained a displaced Salter-Harris type II supination/plantar flexion fracture of the left ankle. He underwent closed reduction under conscious sedation; however, postreduction radiographs showed continued 5-mm anterior widening of the tibial physis. What is the most likely cause of the widening?

. Interposed bony fragment
. Interposition of the periosteum
. Interposition of the anterior tibial tendon
. Persistent malrotation of the physis
. Fibular plastic deformation and malalignment

Correct Answer & Explanation

. Interposed bony fragment

Explanation

Question 1553

Topic: Pediatric Upper Extremity & Spine
A 7-year-old girl who sustained a type III posteromedial extension supracondylar fracture underwent a closed reduction at the time of injury. Figure 27a shows the position of the fracture fragments prior to percutaneous medial and lateral pin fixation. Following surgery, healing was uneventful and the patient regained a full painless range of motion. Fifteen months after the injury, she now reports loss of elbow motion and moderate pain with activity. A current AP radiograph is shown in Figure 27b. What is the most likely cause of her symptoms?
. Latent osteomyelitis from the percutaneous pins
. Muscle weakness because of a lack of postinjury rehabilitation
. Tardy ulnar nerve paralysis from injury by the medial pin
. Osteonecrosis of the trochlea, producing joint incongruity
. A new acute process

Correct Answer & Explanation

. Osteonecrosis of the trochlea, producing joint incongruity

Explanation

The patient sustained a very distal supracondylar fracture of the humerus. Fractures in this area can disrupt the blood vessels supplying the lateral ossification center of the trochlea. With disturbance of the blood supply in this area, local osteonecrosis occurs and disrupts the support for the overlying articular surface, producing joint incongruity and localized degenerative arthritis.

Question 1554

Topic: 4. Pediatrics
A 16-year-old male fell from a roof onto his right shoulder and presents with decreased pulses in his right upper extremity. Imaging reveals a posterior sternoclavicular dislocation. What is the best treatment at this time?
. Nonoperative treatment with a sling and swathe for six weeks
. Nonoperative treatment with immediate active range of motion of the shoulder
. Closed reduction in the emergency room
. Open reduction and percutaneous pinning with thoracic surgery back-up
. Open reduction and ligament reconstruction with thoracic surgery back-up

Correct Answer & Explanation

. Open reduction and ligament reconstruction with thoracic surgery back-up

Explanation

DISCUSSION: Symptomatic acute posterior sternoclavicular dislocations in adolescents should undergo open reduction and ligament (costoclavicular) reconstruction with thoracic surgery back-up. In patients younger than age 20-25, this is usually a physeal injury, as the medial clavicular physis does not close until this age range. Chronic anterior or posterior dislocations are recommended to be treated conservatively, especially if not symptomatic. The review article by Wirth and Rockwood notes the following complications with posterior dislocation: respiratory distress, venous congestion or arterial insufficiency, brachial plexus compression, and myocardial conduction abnormalities. They recommend reconstruction of the costoclavicular ligaments with resection of the medial clavicular head as needed for unstable injuries.

Question 1555

Topic: Pediatric Hip

During total hip arthroplasty for a patient with Crowe Type IV developmental dysplasia of the hip (DDH), a subtrochanteric shortening osteotomy is planned. Which of the following is the most critical reason for performing the shortening osteotomy in this specific patient population?

. To correct excessive femoral anteversion inherent to the dysplastic femur
. To prevent stretch-induced palsy of the sciatic nerve during reduction of the high-riding hip
. To improve the bony ingrowth potential of the extensively porous-coated stem
. To allow simultaneous correction of an associated fixed pelvic obliquity
. To bypass the narrowest portion of the diaphyseal isthmus

Correct Answer & Explanation

. To correct excessive femoral anteversion inherent to the dysplastic femur

Explanation

In Crowe Type IV DDH, the femoral head is completely dislocated and migrated proximally. Bringing the femoral head down to the true acetabulum (which is biomechanically optimal) requires significant lengthening of the limb. Lengthening the leg by more than 4 cm poses a very high risk of stretch injury to the sciatic nerve. A subtrochanteric shortening osteotomy allows the component to be seated in the true acetabulum while protecting the sciatic nerve from excessive tension.

Question 1556

Topic: 4. Pediatrics

A 40-year-old female with bilateral Crowe IV developmental dysplasia of the hip (DDH) presents for primary total hip arthroplasty. To bring the acetabular component down to the true anatomical hip center and avoid permanent sciatic nerve injury from excessive lengthening, a femoral shortening osteotomy is planned. What is the primary anatomical advantage of performing this shortening osteotomy in the subtrochanteric region rather than the supracondylar region?

. It completely eliminates the risk of heterotopic ossification.
. It allows simultaneous correction of the excessive femoral anteversion while preserving the metaphyseal bone for rigid proximal stem fixation.
. It avoids disruption of the descending branch of the lateral femoral circumflex artery.
. It preserves the origin of the vastus lateralis, significantly improving postoperative abductor strength.
. It prevents the need for any diaphyseal stem fixation by relying purely on metaphyseal fit.

Correct Answer & Explanation

. It allows simultaneous correction of the excessive femoral anteversion while preserving the metaphyseal bone for rigid proximal stem fixation.

Explanation

In Crowe IV DDH, the native femur is typically characterized by a narrow intramedullary canal and excessive anteversion. Bringing the hip to the true center often requires >4 cm of lengthening, risking severe sciatic nerve palsy, necessitating a shortening osteotomy. A subtrochanteric shortening osteotomy is preferred because it allows the surgeon to derotate the distal fragment to correct the excessive femoral anteversion while preserving the proximal metaphysis for secure fixation of the femoral stem.

Question 1557

Topic: Pediatric Hip

A radiograph of a 12-year-old boy who has had an insidious onset of pain in the right hip for the past 6 weeks shows diffuse narrowing of the joint space. Examination reveals that he is afrebile, and the range of motion of the hip is less than 50% of normal in all planes. Laboratory studies show an erythrocyte sedimentation rate of 21 mm/hr and a WBC of 11,000/mm3. What is the most likely diagnosis?

. Sickle cell crisis
. Idiopathic chondrolysis
. Hemophilic arthropathy
. Osteoid osteoma of the femoral neck
. Legg-Calve-Perthes disease

Correct Answer & Explanation

. Sickle cell crisis

Explanation

First, sickle cell crisis is a localized area of bone marrow infarction with excruciating pain. Swelling of the extremity and limitation of motion are usually mild. Temperature elevation is usually mild but is >39 degrees celsius in 29% of patients. It is also limited to 3-5 days in duration.This patient has no history of hemophilia given. Hemophilic arthropathy begins with a hemarthrosis.In osteoid osteoma the pain is typically unrelenting, sharp, boring, worse at night, and relieved with aspirin. It is not associated with joint space narrowing.The most common age for Legg-Calve-Perthes disease is 4-8 years. It causes AVN of the femoral head and widening of the medial joint space is an early radiographic finding.In Bleck’s report on Idiopathic Chondrolysis JBJS 1983 nine cases were seen at the reporting institution between 1973 and 1978. The average age was 11.5 years. All the patients were otherwise healthy and had no history of systemic illness of previous trauma. All the patients reported the insidious onset of pain in the anterior part of the hip. All had a decreased passive ROM. Radiographic examination showed regional osteoporosis, premature closure of the femoral capital physis, narrowing of the joint space, and lateral overgrowth of the femoral head on the neck. All laboratory examinations were negative for evidence of infection or rheumatoid arthritis. Treatment consists of administration of aspirin, active non-loading exercise of the hip, and protected weight-bearing with crutches.

Question 1558

Topic: Pediatric Hip

A 13-year-old boy who has a history of a pituitary adenoma has an unstable unilateral slipped capital femoral epiphysis. What is the indication for prophylactic pinning of the contralateral, unslipped side? Review Topic

. Patient gender
. Patient age
. Presentation with an unstable slipped epiphysis
. Coexisting endocrine disorder

Correct Answer & Explanation

. Patient gender

Explanation

Endocrine disorders post the highest risk for bilateral involvement, and prophylactic pinning of the uninvolved side is most often recommended. Risk of contralateral slippage is highest in the youngest patients. In a study by Riad and associates, all girls younger than age 10 and all boys younger than age 12 presenting with a unilateral slipped capital femoral epiphysis subsequently developed a contralateral slip. Initial presentation of an unstable slip has not been shown to be an independent risk factor for later contralateral slippage.

Question 1559

Topic: 4. Pediatrics
A 22-month-old girl has cerebral palsy. Which of the following findings is a good prognostic indicator of the child’s ability to walk in the future?
. Asymmetric tonic neck reflex
. Moro reflex
. Extensor thrust
. Positive parachute reaction
. Absent foot placement

Correct Answer & Explanation

. Positive parachute reaction

Explanation

DISCUSSION: For the parachute test, the examiner holds the child prone and then lowers the child rapidly toward the floor. The parachute reaction is normal or positive if the child reaches toward the floor. The Moro or startle reflex should not be present beyond age 6 months. Asymmetric tonic neck reflex, extensor thrust, and absent foot placement are abnormal findings at any age.

Question 1560

Topic: Pediatric Upper Extremity & Spine
The transverse diameter of the pedicle is most narrow at which of the following levels?
. T1
. T5
. T9
. T12
. L5

Correct Answer & Explanation

. T5

Explanation

DISCUSSION: Of the levels given, T5 has the most narrow pedicle in anatomic studies. One study in patients with scoliosis did note that T7 on the concave side was more narrow than T5, but T7 is not listed here as a possible answer.

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