Menu

4. Pediatrics MCQs

Practice Set 262 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 5221

Topic: 4. Pediatrics

A 6-year-old child sustains a Salter-Harris Type II fracture of the distal femur. What is the most common direction of displacement in this fracture?

. Posterior displacement of the metaphysis.
. Anterior displacement of the metaphysis.
. Medial displacement of the epiphysis.
. Lateral displacement of the metaphysis.
. Pure physeal widening.

Correct Answer & Explanation

. Posterior displacement of the metaphysis.

Explanation

Salter-Harris Type II fractures involve a fracture through the physis and a portion of the metaphysis, leaving the epiphysis intact. In the distal femur, the most common direction of displacement of the metaphysis is posterior, as the distal fragment (epiphysis) typically displaces anteriorly and superiorly due to the pull of the gastrocnemius muscles. This makes posterior displacement of the metaphysis (proximal fragment) the common presentation on X-ray. Pure physeal widening would be a Type I fracture.

Question 5222

Topic: 4. Pediatrics

What is the typical long-term consequence of radiation therapy to a long bone in a prepubescent child for Ewing's Sarcoma?

. Increased bone density in the irradiated field.
. Accelerated growth of the treated limb.
. Growth arrest leading to limb length discrepancy and skeletal deformities.
. Increased risk of osteoporosis.
. Improved joint mobility and reduced pain.

Correct Answer & Explanation

. Growth arrest leading to limb length discrepancy and skeletal deformities.

Explanation

Radiation therapy, particularly in growing children, can damage the physeal growth plates, leading to premature growth arrest in the irradiated bone segment. This commonly results in limb length discrepancies, angular deformities, and other skeletal abnormalities, requiring orthopedic management. It does not increase bone density, accelerate growth, or typically improve joint mobility long-term.

Question 5223

Topic: Pediatric Upper Extremity & Spine

A 16-year-old male sustains a supracondylar femur fracture after a direct blow to the distal thigh. On presentation, he has a weak dorsalis pedis pulse compared to the contralateral side. What is the most appropriate initial diagnostic study to evaluate vascular status?

. Duplex ultrasound.
. Computed tomography angiography (CTA).
. Ankle-brachial index (ABI).
. Magnetic resonance angiography (MRA).
. Immediate surgical exploration of the popliteal artery.

Correct Answer & Explanation

. Ankle-brachial index (ABI).

Explanation

Supracondylar femur fractures are notorious for their association with popliteal artery injury due to the proximity of the fracture fragments to the vessel. In any patient with suspected vascular compromise after a lower limb injury (diminished or absent pulse, pain, pallor, paresthesia, poikilothermia - the '5 Ps'), the initial screening tool is the Ankle-Brachial Index (ABI). An ABI less than 0.9 is highly suspicious for arterial injury. If the ABI is abnormal, or if there are clear hard signs of vascular injury, then a CTA or formal arteriogram is indicated. Immediate surgical exploration is reserved for definitive hard signs of vascular injury (e.g., expanding hematoma, pulsatile bleeding, absent pulse) without time for imaging, or after imaging confirms a repairable injury. Duplex ultrasound can be operator-dependent and MRA is not typically used acutely.

Question 5224

Topic: 4. Pediatrics

A 24-year-old male presents with a Salter-Harris Type IV fracture of the distal tibia following a twisting injury. The fracture line extends through the epiphysis, physis, and metaphysis. Which of the following is the most significant concern with this specific type of physeal injury?

. Nonunion.
. Malunion.
. Post-traumatic arthritis.
. Growth arrest or angular deformity.
. Compartment syndrome.

Correct Answer & Explanation

. Growth arrest or angular deformity.

Explanation

Salter-Harris Type IV fractures involve a fracture line extending through the epiphysis, physis, and metaphysis. These fractures are considered intra-articular and involve the growth plate. The most significant concern with Type IV (and Type V) physeal injuries is the high risk of growth arrest and subsequent angular deformity. This is because the fracture crosses the physis, potentially damaging the chondrocytes, and if not anatomically reduced, a bony bridge can form across the physis. While post-traumatic arthritis (due to articular involvement) and malunion are also risks, growth arrest is the unique and most feared complication of this specific physeal injury type. Nonunion is rare in pediatric fractures.

Question 5225

Topic: 4. Pediatrics

In a patient with Hereditary Multiple Exostoses, which gene is most commonly affected?

. FGFR3
. EXT1
. COL2A1
. STAT3
. PTPN11

Correct Answer & Explanation

. EXT1

Explanation

Mutations in the EXT1 gene are responsible for approximately 60-70% of Hereditary Multiple Exostoses (HME) cases, while EXT2 accounts for 20-30%. Both genes encode glycosyltransferases crucial for heparan sulfate proteoglycan synthesis. FGFR3 is associated with achondroplasia. COL2A1 is associated with Stickler syndrome and other chondrodysplasias. STAT3 and PTPN11 are not primarily linked to HME.

Question 5226

Topic: 4. Pediatrics

A lipoma of the corpus callosum is a rare congenital malformation. What is its typical clinical presentation in adults?

. Rapidly progressive focal neurological deficits
. Acute onset of severe headaches
. Asymptomatic, found incidentally on imaging
. Seizures with associated visual disturbances
. Signs of increased intracranial pressure

Correct Answer & Explanation

. Asymptomatic, found incidentally on imaging

Explanation

Lipomas of the corpus callosum are congenital lesions and are often asymptomatic in adults, discovered incidentally during neuroimaging performed for unrelated reasons. While some patients may present with seizures, headaches, or other neurological symptoms, the majority remain asymptomatic throughout their lives as these lesions are slow-growing and generally non-aggressive.

Question 5227

Topic: 4. Pediatrics

A 5-year-old child sustains a Salter-Harris Type II fracture of the distal tibia. Which zone of the physis is involved in this fracture pattern?

. Germinal zone
. Proliferative zone
. Hypertrophic zone
. Zone of ossification
. Metaphysis

Correct Answer & Explanation

. Hypertrophic zone

Explanation

A Salter-Harris Type II fracture involves the physis (growth plate) and extends through the metaphysis, leaving the epiphysis and articular cartilage intact. The fracture line typically propagates through the hypertrophic zone of the physis, which is the weakest layer due to its large, less cohesive chondrocytes. The germinal and proliferative zones are typically spared, explaining the good prognosis for growth arrest with this type. The metaphysis is the adjacent bone but not the primary zone of physeal involvement.

Question 5228

Topic: 4. Pediatrics

Which characteristic is more typical of the 'healing' phase of a Non-Ossifying Fibroma on a radiograph?

. Increased lucency and expansion.
. Disappearance of the sclerotic rim.
. Migration of the lesion away from the metaphysis into the diaphysis.
. Development of a dense, homogenous central ossification.
. Formation of multiple small cysts within the lesion.

Correct Answer & Explanation

. Development of a dense, homogenous central ossification.

Explanation

In the healing or latent phase, a NOF typically shows increasing central sclerosis, eventually becoming a dense, homogenous area of ossified bone as the fibrous tissue is replaced. The lesion also tends to migrate away from the physis into the diaphysis due to bone growth. Increased lucency, loss of sclerotic rim, or cyst formation are not signs of healing NOF.

Question 5229

Topic: 4. Pediatrics

What is the typical growth pattern of a Non-Ossifying Fibroma in relation to the physis?

. It originates in the physis and expands into the metaphysis.
. It originates in the diaphysis and grows towards the physis.
. It originates in the metaphysis and migrates away from the physis as the bone grows.
. It causes premature fusion of the physis.
. It causes widening of the physis.

Correct Answer & Explanation

. It originates in the metaphysis and migrates away from the physis as the bone grows.

Explanation

Non-Ossifying Fibromas originate in the metaphysis (specifically the cortex near the growth plate). As the child grows, the growth plate migrates away from the lesion, causing the lesion to appear to 'migrate' or be pushed into the diaphysis (diaphyseal migration). It does not originate in the physis, nor does it typically cause premature fusion or widening of the physis.

Question 5230

Topic: 4. Pediatrics

When biopsying a lesion in a child's physis-crossing region (e.g., proximal tibia), what is the MOST important technical consideration?

. Using a smaller gauge needle to minimize physis damage.
. Avoiding the physis entirely by targeting only the metaphyseal component.
. Performing the biopsy under general anesthesia for better patient cooperation.
. Placing the biopsy parallel to the physis if possible, and minimizing its disruption.
. Ensuring a large enough tissue sample for molecular diagnostics.

Correct Answer & Explanation

. Placing the biopsy parallel to the physis if possible, and minimizing its disruption.

Explanation

When a lesion crosses or is in close proximity to the physis, the most important consideration is to minimize damage to the physis itself to prevent growth arrest or angular deformity. If possible, the biopsy should be placed parallel to the physis or through an area that will be resected during definitive surgery. Minimizing disruption of the physis is key. While using a smaller needle and general anesthesia are good practices, protecting the growth plate is paramount for long-term function in a growing child.

Question 5231

Topic: 4. Pediatrics

A 6-year-old child sustains a Salter-Harris Type II fracture of the distal tibia. The fracture is displaced. What is the optimal management strategy?

. Open reduction and internal fixation with screws.
. Percutaneous pinning with K-wires across the physis.
. Closed reduction and long leg cast immobilization.
. Observation and protected weight bearing.
. Immediate referral for growth plate ablation.

Correct Answer & Explanation

. Closed reduction and long leg cast immobilization.

Explanation

Salter-Harris Type II fractures involve the physis and metaphysis, sparing the epiphysis and joint surface, and generally have a good prognosis. For displaced fractures, closed reduction is the preferred treatment to avoid surgical disruption of the physis. Once reduced, a long leg cast provides stable immobilization. Open reduction and internal fixation, particularly with screws across the physis, carries a significant risk of growth arrest. Percutaneous pinning can be used in unstable reductions, but pins should ideally avoid crossing the physis or, if necessary, be smooth and removed early. Observation is for minimally displaced or undisplaced fractures. Growth plate ablation is not indicated.

Question 5232

Topic: 4. Pediatrics
A 14-year-old male sustains a Salter-Harris Type III fracture of the distal tibia. Which of the following is true regarding its management?
. Non-operative management is always indicated due to physeal involvement.
. Open reduction is required for any displacement greater than 1mm.
. Growth arrest is the most common complication.
. It is an intra-articular fracture requiring anatomical reduction.
. Percutaneous pinning should cross the physis in a divergent pattern.

Correct Answer & Explanation

. It is an intra-articular fracture requiring anatomical reduction.

Explanation

A Salter-Harris Type III fracture involves the epiphysis and physis, meaning it extends into the joint. Therefore, it is an intra-articular fracture, and anatomical reduction (often requiring open reduction and internal fixation with screws parallel to the physis) is crucial to restore joint congruity and prevent premature degenerative arthritis. While growth arrest can occur, post-traumatic arthritis is a major concern. Non-operative management is only for truly non-displaced fractures. Percutaneous pinning should avoid crossing the physis if possible, or use smooth pins to minimize physeal damage.

Question 5233

Topic: 4. Pediatrics

A 6-month-old infant presents with a spiral fracture of the tibia, with no history of significant trauma provided by the parents. What is the most critical next step in evaluation?

. Apply a long leg cast and discharge.
. Obtain a skeletal survey to rule out child abuse.
. Prescribe antibiotics for suspected osteomyelitis.
. Refer to pediatric orthopedics for immediate surgery.
. Order a bone scan to assess fracture healing.

Correct Answer & Explanation

. Obtain a skeletal survey to rule out child abuse.

Explanation

A spiral fracture of the tibia in a non-ambulatory infant with an inconsistent or absent history of trauma should raise strong suspicion for non-accidental trauma (child abuse), also known as a 'toddler's fracture' when walking, but concerning in an infant. The most critical next step is to obtain a skeletal survey (babygram) to look for other occult fractures of varying ages, which would confirm a diagnosis of child abuse. While the fracture needs stabilization, ruling out child abuse takes precedence. Antibiotics and immediate surgery are not indicated based on the initial presentation. A bone scan is not for initial diagnosis of abuse.

Question 5234

Topic: 4. Pediatrics

In a child, what is the most common direction of a supracondylar humerus fracture displacement?

. Anteriorly and medially
. Posteriorly and medially
. Posteriorly and laterally
. Anteriorly and laterally
. Direct impaction without displacement

Correct Answer & Explanation

. Posteriorly and medially

Explanation

The most common type of supracondylar humerus fracture in children is the extension-type injury, resulting from a fall onto an outstretched hand with the elbow extended. This typically leads to posterior and medial displacement of the distal fragment relative to the proximal humerus. Understanding this common displacement pattern is critical for reduction and fixation.

Question 5235

Topic: 4. Pediatrics

What is the common mechanism of injury for a medial epicondyle avulsion fracture in a pediatric athlete?

. Direct blow to the medial elbow
. Fall onto an outstretched hand with elbow extension
. Repetitive varus stress during throwing
. Repetitive valgus stress during throwing
. Hyperextension injury

Correct Answer & Explanation

. Repetitive valgus stress during throwing

Explanation

Medial epicondyle avulsion fractures in pediatric athletes commonly occur due to repetitive valgus stress during the acceleration phase of throwing. The strong pull of the flexor-pronator mass and the tension on the ulnar collateral ligament complex avulse the unfused medial epicondyle physis. Direct blows or falls can cause fractures, but this specific mechanism is highly associated with throwing athletes.

Question 5236

Topic: 4. Pediatrics

A 10-year-old child falls on an outstretched hand and sustains a supracondylar humerus fracture. Radiographs show significant displacement with an intact radial pulse but a pale, pulseless hand upon examination in the emergency department. Which is the MOST appropriate initial management step?

. Immediate closed reduction and percutaneous pinning
. Application of a long arm splint and observation for 24 hours
. Emergent surgical exploration of the brachial artery
. Perform an arteriogram to assess the arterial injury
. Attempt gentle closed reduction under sedation, re-assess perfusion

Correct Answer & Explanation

. Attempt gentle closed reduction under sedation, re-assess perfusion

Explanation

In a supracondylar humerus fracture with signs of vascular compromise (pale, pulseless hand), the immediate priority is to restore perfusion. The most appropriate initial step is to attempt a gentle closed reduction under sedation. If perfusion is restored after reduction, then percutaneous pinning can proceed. If perfusion does not return after a successful reduction, or if the initial reduction is unsuccessful, then emergent surgical exploration of the brachial artery is indicated. Immediate surgical exploration without attempting reduction first is generally not recommended, as the vessel may be kinked or entrapped, not necessarily transected. An arteriogram takes too long in an emergent situation with active ischemia. Observation is inappropriate. Immediate pinning without addressing the vascular status is also incorrect.

Question 5237

Topic: 4. Pediatrics

A 10-year-old child presents with a lateral condyle fracture of the humerus. Which classification system is commonly used for this injury, and what is its primary focus?

. AO Classification; fracture pattern and comminution
. Mason-Hotchkiss Classification; radial head involvement
. Milch Classification; amount of articular involvement and stability
. Salter-Harris Classification; physis involvement and growth plate injury
. O'Driscoll Classification; coronoid process fracture size

Correct Answer & Explanation

. Milch Classification; amount of articular involvement and stability

Explanation

The Milch classification is commonly used for lateral condyle fractures of the humerus in children. It divides these fractures into Type I (fracture through the capitellar ossification center, stable) and Type II (fracture extending through the trochlea, less stable, usually involving the entire lateral condyle). The key distinction is the extent of articular involvement and stability, guiding treatment. Salter-Harris describes epiphyseal plate injuries in general but Milch is specific to lateral condyle. AO and Mason are for adults, O'Driscoll for coronoid.

Question 5238

Topic: 4. Pediatrics

On an 84-year-old lady's shoulder X-ray, you notice an anatomical variant where the acromion is not completely fused, appearing as a separate ossicle. This is known as:

. Sprengel's deformity
. Os acromiale
. Osgood-Schlatter lesion
. Accessory navicular
. Pelligrini-Stieda lesion

Correct Answer & Explanation

. Os acromiale

Explanation

An os acromiale is a developmental anomaly where one or more of the acromial ossification centers fail to fuse. It can predispose to subacromial impingement and rotator cuff tears. Sprengel's deformity is congenital elevation of the scapula. Osgood-Schlatter is apophysitis of the tibial tubercle. Accessory navicular is an extra bone in the foot. Pelligrini-Stieda lesion is calcification of the MCL at the femoral attachment.

Question 5239

Topic: 4. Pediatrics

Which of the following conservative treatments has the strongest evidence for improving pain in pediatric spondylolysis with active pars defect?

. Complete bed rest
. Opioid analgesics
. Lumbar bracing (e.g., Boston brace or rigid thoracolumbosacral orthosis)
. Regular stretching without activity modification
. High-impact sports activity continuation

Correct Answer & Explanation

. Lumbar bracing (e.g., Boston brace or rigid thoracolumbosacral orthosis)

Explanation

For pediatric spondylolysis with active pars lesions (e.g., confirmed by SPECT/CT or MRI edema) that are symptomatic, lumbar bracing combined with activity modification (restricting aggravating activities) has the strongest evidence for promoting healing and relieving pain. Complete bed rest is rarely indicated and detrimental. Opioids are inappropriate for chronic pediatric pain. Activity modification is key, not just stretching, and high-impact sports will hinder healing.

Question 5240

Topic: 4. Pediatrics

A 13-year-old elite baseball pitcher presents with insidious onset of shoulder pain during the late cocking phase of throwing. Radiographs demonstrate widening and lateral fragmentation of the proximal humeral physis. What is the most appropriate initial management?

. Arthroscopic labral repair
. Corticosteroid injection into the subacromial space
. Absolute rest from throwing for 3 months followed by a structured return-to-throw program
. Percutaneous in situ screw fixation of the physis
. Physical therapy focusing solely on anterior capsular stretching

Correct Answer & Explanation

. Absolute rest from throwing for 3 months followed by a structured return-to-throw program

Explanation

The patient has 'Little League Shoulder', which is a proximal humeral epiphysiolysis caused by repetitive rotational stress on the open physis during throwing. The standard of care is non-operative, primarily consisting of complete rest from throwing for 2 to 3 months, followed by physical therapy focusing on core/scapular mechanics, and finally a graduated return-to-throwing program.

Test Yourself

Switch to an interactive, timed exam simulation to truly master this topic.

On this Page