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Pediatric Upper Extremity & Spine MCQs

Practice Set 13 of 33

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

Question 241

Topic: Pediatric Upper Extremity & Spine

In a 13-year-old female with adolescent idiopathic scoliosis, which of the following radiographic parameters best defines a 'structural' minor curve that must be included in the fusion construct according to the Lenke classification system?

. Coronal Cobb angle > 25 degrees on side-bending radiographs
. Coronal Cobb angle > 40 degrees on standing PA radiographs
. Apical vertebral rotation > Grade 2
. Thoracic kyphosis > +20 degrees
. Sagittal vertical axis > 5 cm

Correct Answer & Explanation

. Coronal Cobb angle > 25 degrees on side-bending radiographs

Explanation

The Lenke classification defines a minor curve as structural if it lacks sufficient flexibility. Specifically, if the coronal Cobb angle remains > 25 degrees on lateral side-bending radiographs, it is considered structural and should be included in the fusion construct.

Question 242

Topic: Pediatric Upper Extremity & Spine
A 6-year-old boy sustains a Gartland type III supracondylar humerus fracture. Upon presentation, his hand is pale and pulseless. After urgent closed reduction and percutaneous pinning, the hand becomes pink and warm with brisk capillary refill, but the radial pulse remains impalpable. What is the most appropriate next step in management?
. Immediate open surgical exploration of the brachial artery
. Perform a CT angiogram of the upper extremity
. Observe and admit for serial neurovascular checks
. Remove the pins and perform open reduction
. Administer intravenous heparin

Correct Answer & Explanation

. Observe and admit for serial neurovascular checks

Explanation

In a 'pink, pulseless' hand after reduction of a pediatric supracondylar humerus fracture, as long as peripheral perfusion (warmth, color, capillary refill) is adequate, the current standard of care is careful clinical observation. The lack of a palpable pulse is often due to vasospasm or non-flow-limiting intimal injury.

Question 243

Topic: Pediatric Upper Extremity & Spine

A 7-year-old boy has a swollen and deformed right arm after falling off his bicycle. Radiographs reveal a completely displaced posterolateral supracondylar humeral fracture. Examination reveals a warm, pink hand and forearm but absent pulses. What is the next most appropriate step in management?

General Orthopedics Board Review 2026: High-Yield MCQs (Set 14) - Figure 37

. Angiography
. Immediate closed reduction and casting in extension
. Surgical exploration and repair of the artery, followed by skeletal stabilization
. Closed reduction and pinning, followed by reassessment of the vascular status
. Magnetic resonance angiography (MRA)

Correct Answer & Explanation

. Surgical exploration and repair of the artery, followed by skeletal stabilization

Explanation

The incidence of vascular injury in supracondylar humeral fractures is directly related to the degree and direction of displacement. Significant posterior lateral displacement tends to result in brachial artery and median nerve injuries, and posterior medial displacement may lead to radial nerve injury. The brachial artery is always injured at the level of the fracture; therefore, angiography or MRA will not assist in locating the injury. The treatment of choice is surgical reduction and stabilization of the fracture, followed by reassessment of the vascular status. If the hand is pink and warm or pulses can be detected with doppler, it is reasonable to follow the extremity closely after surgery. If the arm becomes pulseless and white, immediate anterior exploration of the arm is indicated. The artery is often entrapped in the fracture and once extricated, will provide adequate blood flow. If the artery is injured, a primary repair or vein graft is needed. Shaw BA: The role of angiography in assessing vascular injuries associated with supracondylar humerus fractures remains controversial. J Pediatr Orthop 1998;18:273. Sabharwal S, Tredwell SJ, Beauchamp RD, et al: Management of pulseless pink hand in pediatric supracondylar fractures of humerus. J Pediatr Orthop 1997;17:303-310.

Question 244

Topic: Pediatric Upper Extremity & Spine
A 6-year-old boy sustains a completely displaced, extension-type Gartland type III supracondylar humerus fracture. Prior to operative intervention, a thorough neurologic examination reveals that he is unable to actively flex the interphalangeal joint of his thumb and the distal interphalangeal joint of his index finger. Which of the following nerves has most likely been injured?
. Radial nerve
. Ulnar nerve
. Anterior interosseous nerve (AIN)
. Posterior interosseous nerve (PIN)
. Musculocutaneous nerve

Correct Answer & Explanation

. Anterior interosseous nerve (AIN)

Explanation

The patient demonstrates an inability to flex the interphalangeal joint of the thumb (innervated by the flexor pollicis longus) and the distal interphalangeal joint of the index finger (innervated by the flexor digitorum profundus). This motor deficit, often tested by asking the patient to make an 'A-OK' sign, is indicative of an anterior interosseous nerve (AIN) palsy. The AIN is a branch of the median nerve and is the most commonly injured nerve in pediatric extension-type supracondylar humerus fractures.

Question 245

Topic: Pediatric Upper Extremity & Spine
A 6-year-old boy presents with a Gartland type III extension-type supracondylar humerus fracture. On examination, the radial pulse is absent, but the hand is warm and pink with brisk capillary refill. What is the most appropriate next step in management?
. Emergent CT angiogram of the upper extremity
. Immediate open vascular exploration via an anterior approach
. Urgent closed reduction and percutaneous pinning
. Observation and admission for 24 hours
. Prophylactic forearm fasciotomies

Correct Answer & Explanation

. Urgent closed reduction and percutaneous pinning

Explanation

A 'pulseless but pink' (well-perfused) hand following a displaced pediatric supracondylar humerus fracture indicates adequate collateral circulation. The initial treatment is urgent closed reduction and pinning to relieve pressure on the brachial artery.

Question 246

Topic: Pediatric Upper Extremity & Spine

In the Lenke classification of adolescent idiopathic scoliosis, a lumbar curve is considered a 'structural' minor curve if it bends out to what minimum Cobb angle on supine side-bending radiographs?

. 10 degrees
. 15 degrees
. 20 degrees
. 25 degrees
. 30 degrees

Correct Answer & Explanation

. 25 degrees

Explanation

In the Lenke classification, a minor curve is structural if it has a residual Cobb angle of 25 degrees or greater on supine lateral bending radiographs, or if there is kyphosis of at least +20 degrees.

Question 247

Topic: Pediatric Upper Extremity & Spine

A 14-year-old female with Adolescent Idiopathic Scoliosis has a right thoracic curve. She is Risser 0 and pre-menarchal. Her curve measures 35 degrees. What is the most appropriate treatment?

. Observation with serial radiographs every 6 months
. Physical therapy and core strengthening
. Thoracolumbosacral orthosis (TLSO) bracing
. Posterior spinal fusion
. Anterior spinal tethering

Correct Answer & Explanation

. Thoracolumbosacral orthosis (TLSO) bracing

Explanation

TLSO bracing is indicated for skeletally immature patients (Risser 0-2) with progressive curves measuring between 25 and 40 degrees to halt curve progression.

Question 248

Topic: Pediatric Upper Extremity & Spine

A 13-year-old premenarchal girl (Risser 0) has a right thoracic curve measuring 32 degrees. What is the most appropriate management?

. Observation with radiographs in 6 months
. Thoracolumbosacral orthosis (TLSO) bracing for 8 hours per day
. Thoracolumbosacral orthosis (TLSO) bracing for 16-23 hours per day
. Posterior spinal fusion
. Anterior spinal tethering

Correct Answer & Explanation

. Thoracolumbosacral orthosis (TLSO) bracing for 16-23 hours per day

Explanation

Bracing is indicated for skeletally immature patients (Risser 0-2) with curves between 25 and 45 degrees. A dose-response relationship exists, with 16-23 hours per day providing the most effective curve progression prevention.

Question 249

Topic: Pediatric Upper Extremity & Spine

In the Lenke classification for adolescent idiopathic scoliosis, a curve with a structural proximal thoracic curve, a structural main thoracic curve, and a nonstructural thoracolumbar curve is classified as which type?

. Type 1 (Main Thoracic)
. Type 2 (Double Thoracic)
. Type 3 (Double Major)
. Type 4 (Triple Major)
. Type 5 (Thoracolumbar/Lumbar)

Correct Answer & Explanation

. Type 2 (Double Thoracic)

Explanation

Lenke Type 2 is a Double Thoracic curve pattern, characterized by structural proximal and main thoracic curves, while the thoracolumbar/lumbar curve remains nonstructural.

Question 250

Topic: Pediatric Upper Extremity & Spine

A 13-year-old premenarchal girl presents for evaluation of a spinal deformity. Examination reveals a right thoracic prominence. Radiographs show a right-sided structural main thoracic curve of 36 degrees. Her Risser stage is 1. What is the most appropriate next step in management?

. Observation with repeat radiographs in 6 months
. Nighttime-only bending brace
. Thoracolumbosacral orthosis (TLSO) for 16-23 hours per day
. Posterior spinal fusion with instrumentation
. Anterior vertebral body tethering

Correct Answer & Explanation

. Thoracolumbosacral orthosis (TLSO) for 16-23 hours per day

Explanation

This patient has Adolescent Idiopathic Scoliosis (AIS) with a curve between 25-45 degrees, significant remaining growth (premenarchal, Risser 1), and is at high risk for progression. Full-time bracing (TLSO) with a dose-response goal of >18 hours daily has been shown to effectively decrease the progression of curves to the surgical threshold.

Question 251

Topic: Pediatric Upper Extremity & Spine

A 14-year-old girl is diagnosed with Adolescent Idiopathic Scoliosis. Her standing posteroanterior radiograph shows a 50-degree right thoracic curve and a 35-degree left lumbar curve. On dynamic side-bending radiographs, the thoracic curve corrects to 30 degrees and the lumbar curve corrects to 15 degrees. According to the Lenke Classification system, how is the lumbar curve defined?

. Major structural
. Minor structural
. Non-structural
. Compensatory structural
. Fractional curve

Correct Answer & Explanation

. Non-structural

Explanation

In the Lenke Classification system, a minor curve is considered non-structural if it bends out to less than 25 degrees on side-bending radiographs. Since her lumbar curve corrects to 15 degrees, it is non-structural, classifying this as a Lenke Type 1 (Main Thoracic) curve.

Question 252

Topic: Pediatric Upper Extremity & Spine

A 12-year-old girl is evaluated for a spinal deformity. She is premenarchal, has open triradiate cartilages, and is Risser 0. Radiographs reveal a right thoracic adolescent idiopathic scoliosis (AIS) curve of 35 degrees. What is the most appropriate management?

. Observation with follow-up radiographs in 6 months
. Part-time bracing (8-10 hours/day)
. Full-time bracing (16-23 hours/day)
. Posterior spinal fusion
. Physical therapy and core strengthening

Correct Answer & Explanation

. Full-time bracing (16-23 hours/day)

Explanation

In a highly immature patient (Risser 0, open triradiate cartilage, premenarchal) with an AIS curve between 25 and 44 degrees, full-time bracing (16-23 hours/day) is indicated to prevent curve progression. Observation is inappropriate given her extremely high risk of progression.

Question 253

Topic: Pediatric Upper Extremity & Spine

A 14-year-old Risser 0 female presents with adolescent idiopathic scoliosis. A standing posteroanterior radiograph demonstrates a right thoracic curve measuring 52 degrees and a left lumbar curve measuring 35 degrees. On supine lateral bending films, the thoracic curve reduces to 28 degrees and the lumbar curve reduces to 15 degrees. Sagittal alignment is normal. What is the most appropriate surgical strategy?

. Selective thoracic fusion
. Anterior lumbar interbody fusion
. Posterior spinal fusion from T4 to L4
. Vertical Expandable Prosthetic Titanium Rib (VEPTR) insertion
. Thoracolumbosacral orthosis (TLSO) bracing

Correct Answer & Explanation

. Selective thoracic fusion

Explanation

This patient has a Lenke Type 1 curve, defined by a structural main thoracic curve (residual bend >25 degrees) and a non-structural lumbar curve (bends to <25 degrees). The gold standard surgical treatment is a selective thoracic fusion, which corrects the primary deformity while preserving lumbar motion segments.

Question 254

Topic: Pediatric Upper Extremity & Spine

According to the Lenke Classification system for adolescent idiopathic scoliosis, a proximal thoracic curve is considered structural if a supine side-bending radiograph shows a residual Cobb angle of at least what magnitude?

. 10 degrees
. 15 degrees
. 20 degrees
. 25 degrees
. 35 degrees

Correct Answer & Explanation

. 25 degrees

Explanation

In the Lenke classification, minor curves are considered structural if they fail to bend out to less than 25 degrees on side-bending radiographs, or if there is a regional kyphosis of >20 degrees.

Question 255

Topic: Pediatric Upper Extremity & Spine

A 12-year-old premenarchal girl (Risser 0) presents with Adolescent Idiopathic Scoliosis. Standing radiographs demonstrate a right thoracic curve of 32 degrees. What is the most appropriate management?

. Observation with radiographs in 6 months
. Nighttime bending brace
. Thoracolumbosacral orthosis (TLSO) bracing
. Posterior spinal fusion with instrumentation
. Anterior vertebral body tethering

Correct Answer & Explanation

. Thoracolumbosacral orthosis (TLSO) bracing

Explanation

A patient with significant growth remaining (premenarchal, Risser 0) and a curve between 25 and 45 degrees meets the classic indications for bracing. A TLSO worn for 16-23 hours a day is standard of care to halt progression.

Question 256

Topic: Pediatric Upper Extremity & Spine

According to the Lenke classification for adolescent idiopathic scoliosis, a minor curve is considered 'structural' and should generally be included in the fusion construct if it demonstrates which characteristic on side-bending radiographs?

. Fails to correct to less than 25 degrees
. Fails to correct to 0 degrees
. Shows greater than Grade II Nash-Moe rotation
. Maintains a Cobb angle of >10 degrees
. Shows translation greater than 1 cm

Correct Answer & Explanation

. Fails to correct to less than 25 degrees

Explanation

In the Lenke classification, a secondary or minor curve is defined as structural if it remains greater than or equal to 25 degrees on maximum voluntary side-bending radiographs.

Question 257

Topic: Pediatric Upper Extremity & Spine

According to the Lenke Classification for Adolescent Idiopathic Scoliosis, what specific radiographic criterion defines a "structural" proximal thoracic curve?

. Cobb angle > 25 degrees on side-bending radiographs
. Cobb angle > 10 degrees on side-bending radiographs
. Kyphosis (T2-T5) of at least +20 degrees
. Apical vertebral translation > 2 cm
. Nash-Moe rotation of Grade 3

Correct Answer & Explanation

. Cobb angle > 25 degrees on side-bending radiographs

Explanation

In the Lenke classification, a minor curve is considered structural if it does not correct to less than 25 degrees on supine side-bending radiographs, or if there is a regional kyphosis of >20 degrees.

Question 258

Topic: Pediatric Upper Extremity & Spine

At what Risser stage and Cobb angle is rigid brace treatment typically indicated for Adolescent Idiopathic Scoliosis (AIS)?

. Risser 0-2 with a curve of 15-20 degrees
. Risser 0-2 with a curve of 25-40 degrees
. Risser 4-5 with a curve of 25-40 degrees
. Risser 0-2 with a curve > 50 degrees
. Risser 4-5 with a curve of 15-20 degrees

Correct Answer & Explanation

. Risser 0-2 with a curve of 25-40 degrees

Explanation

Bracing for AIS is indicated in skeletally immature patients (Risser 0-2, pre-menarchal) with a Cobb angle between 25 and 40 degrees, or documented curve progression of 5 degrees in curves between 20 and 25 degrees.

Question 259

Topic: Pediatric Upper Extremity & Spine

A 14-year-old female with adolescent idiopathic scoliosis (AIS) has a right main thoracic curve of 52 degrees and a left lumbar curve of 34 degrees. On side-bending radiographs, the thoracic curve corrects to 30 degrees and the lumbar curve corrects to 15 degrees. Thoracic kyphosis (T5-T12) is +15 degrees. According to the Lenke classification, what is the appropriate curve type and recommended fusion approach?

. Lenke 1 (Main Thoracic), selective thoracic fusion
. Lenke 2 (Double Thoracic), fusion extending to the upper thoracic spine
. Lenke 3 (Double Major), combined thoracic and lumbar fusion
. Lenke 5 (Thoracolumbar/Lumbar), selective lumbar fusion
. Lenke 6 (Thoracolumbar/Lumbar-Main Thoracic), combined fusion

Correct Answer & Explanation

. Lenke 1 (Main Thoracic), selective thoracic fusion

Explanation

This is a Lenke 1 curve because the main thoracic curve is structural (>25 degrees on bending) while the lumbar curve is nonstructural (<25 degrees on bending). The standard surgical treatment for a Lenke 1 curve is a selective thoracic fusion, sparing the lumbar spine.

Question 260

Topic: Pediatric Upper Extremity & Spine

A 10-year-old boy sustains a supracondylar humerus fracture. After reduction, he is unable to flex the interphalangeal joint of his thumb and the distal interphalangeal joint of his index finger. If this specific nerve injury persists, which of the following muscles will also demonstrate denervation on electromyography?

. Flexor carpi radialis
. Pronator teres
. Pronator quadratus
. Flexor digitorum superficialis
. Abductor pollicis brevis

Correct Answer & Explanation

. Pronator quadratus

Explanation

The patient has an anterior interosseous nerve (AIN) palsy, a branch of the median nerve. The AIN innervates the flexor pollicis longus, the flexor digitorum profundus to the index and long fingers, and the pronator quadratus.

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