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 461
Topic: Pediatric Upper Extremity & Spine
A 14-year-old girl is diagnosed with Adolescent Idiopathic Scoliosis. Upright radiographs demonstrate a main thoracic curve of 55 degrees and a lumbar curve of 35 degrees. On lateral bending films, the thoracic curve corrects to 40 degrees, and the lumbar curve corrects to 30 degrees. According to the Lenke classification system, what type of curve pattern does she have?
Correct Answer & Explanation
. Lenke Type 3
Explanation
This is a Lenke Type 3 (Double Major) curve. The main thoracic curve is structural (>25 degrees on bending), and the lumbar curve is also structural (fails to correct to <25 degrees on side bending).
Question 462
Topic: Pediatric Upper Extremity & Spine
In the surgical planning for Adolescent Idiopathic Scoliosis using the Lenke classification, which curve type is defined specifically as a 'Double Major' curve?
Correct Answer & Explanation
. Lenke 3
Explanation
In the Lenke classification system, Lenke 3 is defined as a Double Major curve. This indicates both the Main Thoracic and Lumbar/Thoracolumbar curves are structural, but the Main Thoracic curve is larger.
Question 463
Topic: Pediatric Upper Extremity & Spine
In the Lenke classification of Adolescent Idiopathic Scoliosis, a structural curve is determined by side-bending radiographs. Which of the following defines a structural proximal thoracic curve?
Correct Answer & Explanation
. Cobb angle > 25 degrees
Explanation
In the Lenke classification for adolescent idiopathic scoliosis, a minor curve is considered structural if the Cobb angle remains 25 degrees or greater on side-bending radiographs. Additionally, regional kyphosis of 20 degrees or more also defines a structural curve.
Question 464
Topic: Pediatric Upper Extremity & Spine
A 14-year-old female with adolescent idiopathic scoliosis (AIS) has a standing PA radiograph demonstrating a main thoracic curve of 55 degrees and a lumbar curve of 35 degrees. On supine side-bending radiographs, the lumbar curve corrects to 15 degrees. What is her Lenke curve type, and what is the standard surgical strategy?
Correct Answer & Explanation
. Lenke 1 (Selective thoracic fusion)
Explanation
This is a Lenke 1 (Main Thoracic) curve pattern because the compensatory lumbar curve is non-structural (corrects to less than 25 degrees on side-bending). The standard surgical approach is a selective thoracic fusion, sparing the lumbar spine to preserve motion.
Question 465
Topic: Pediatric Upper Extremity & Spine
A patient presents with median nerve compression symptoms above the elbow. Imaging reveals a supracondylar process. The ligament of Struthers connects this process to which anatomical structure?
Correct Answer & Explanation
. Medial epicondyle
Explanation
The ligament of Struthers is a fibrous band that extends from an anomalous supracondylar process on the anteromedial humerus to the medial epicondyle. It can compress the median nerve and brachial artery.
Question 466
Topic: Pediatric Upper Extremity & Spine
A patient presents with an inability to flex the interphalangeal joint of the thumb and the distal interphalangeal joint of the index finger after a supracondylar humerus fracture. The affected nerve normally passes between the two heads of which muscle?
Correct Answer & Explanation
. Pronator teres
Explanation
The clinical presentation describes anterior interosseous nerve (AIN) palsy. The AIN is a branch of the median nerve, which enters the forearm by passing between the superficial and deep heads of the pronator teres.
Question 467
Topic: Pediatric Upper Extremity & Spine
A baseball pitcher undergoes ulnar collateral ligament (UCL) reconstruction. The graft is secured anatomically to the sublime tubercle. On which specific anatomical structure is the sublime tubercle located?
Correct Answer & Explanation
. Anteromedial aspect of the coronoid process
Explanation
The anterior bundle of the UCL is the primary restraint to valgus stress at the elbow. It originates on the anterior undersurface of the medial epicondyle and inserts on the sublime tubercle of the anteromedial coronoid process.
Question 468
Topic: Pediatric Upper Extremity & Spine
A 14-year-old male presents with a leg length discrepancy. A scanogram confirms the right femur is 3.5 cm shorter than the left. He is at Risser 4, and his bone age matches his chronologic age. Which of the following is the most appropriate management?
Correct Answer & Explanation
. Contralateral femoral shortening osteotomy
Explanation
Because the patient is near skeletal maturity (Risser 4), an epiphysiodesis will yield minimal correction. For a 3.5 cm discrepancy at maturity, a contralateral acute shortening osteotomy is reliable and avoids the higher complication rates associated with lengthening procedures.
Question 469
Topic: Pediatric Upper Extremity & Spine
According to the Lenke Classification system for Adolescent Idiopathic Scoliosis, what defines a structural proximal thoracic (PT) curve?
Correct Answer & Explanation
. Cobb angle > 25 degrees on side-bending radiographs or T2-T5 kyphosis > 20 degrees
Explanation
In the Lenke classification, a minor curve is considered structural if it does not correct to less than 25 degrees on side-bending radiographs, or if there is a regional kyphosis of at least 20 degrees.
Question 470
Topic: Pediatric Upper Extremity & Spine
A 12-year-old female presents with a 32-degree right thoracic curve. She has not reached menarche. Radiographs demonstrate open triradiate cartilages and a Risser stage of 0. What is the most appropriate management?
Correct Answer & Explanation
. Thoracolumbosacral orthosis (TLSO) bracing
Explanation
TLSO bracing is indicated for patients with Adolescent Idiopathic Scoliosis (AIS) who have a curve between 25 and 45 degrees and significant remaining growth (Risser 0-2, premenarchal, open triradiate cartilages).
Question 471
Topic: Pediatric Upper Extremity & Spine
In a patient with Adolescent Idiopathic Scoliosis, which of the following clinical milestones corresponds with the period of greatest risk for rapid curve progression?
Correct Answer & Explanation
. Peak height velocity
Explanation
The highest risk of curve progression in AIS occurs during the adolescent growth spurt, specifically at the time of peak height velocity. This typically occurs just prior to menarche and Risser 1, while triradiate cartilages are still open.
Question 472
Topic: Pediatric Upper Extremity & Spine
A 12-year-old girl with Down syndrome presents with a 45-degree thoracic scoliotic curve.
Compared to adolescent idiopathic scoliosis (AIS), how does the management and prognosis of scoliosis in patients with Down syndrome typically differ?
Correct Answer & Explanation
. There is a higher rate of progression and bracing is often poorly tolerated
Explanation
Scoliosis in Down syndrome has a higher incidence and progression rate than standard AIS. Furthermore, orthotic bracing is often poorly tolerated and less effective due to the patient's underlying hypotonia and body habitus.
Question 473
Topic: Pediatric Upper Extremity & Spine
In a 13-year-old female with adolescent idiopathic scoliosis, which of the following combinations of factors represents the highest risk for curve progression?
Correct Answer & Explanation
. Risser stage 0, open triradiate cartilage, and a 30-degree curve
Explanation
The risk of curve progression in AIS is highest in patients with significant skeletal immaturity (Risser 0, open triradiate cartilage, pre-menarchal) combined with a larger initial curve magnitude (>25 degrees).
Question 474
Topic: Pediatric Upper Extremity & Spine
In the Lenke classification system for adolescent idiopathic scoliosis, a proximal thoracic curve is considered "structural" and must be included in the fusion construct if the curve bends out to what minimum Cobb angle on side-bending radiographs?
Correct Answer & Explanation
. Greater than or equal to 25 degrees
Explanation
According to the Lenke classification, minor curves are considered structural if they do not bend out to less than 25 degrees (i.e., remain ≥25 degrees) on side-bending radiographs, or if there is kyphosis ≥ +20 degrees.
Question 475
Topic: Pediatric Upper Extremity & Spine
A 12-year-old female with Adolescent Idiopathic Scoliosis (AIS) presents with a right thoracic curve. Which of the following combinations of factors indicates the highest risk for curve progression?
Correct Answer & Explanation
. Curve of 25 degrees, Risser 0, pre-menarchal
Explanation
The risk of progression in AIS is highest during peak growth velocity. A curve of 25 degrees in a pre-menarchal patient with a Risser 0 score carries an approximately 68-100% risk of progression, according to Lonstein and Carlson criteria.
Question 476
Topic: Pediatric Upper Extremity & Spine
A 6-year-old boy falls from the monkey bars and sustains an extension-type supracondylar humerus fracture. Radiographs in the emergency department reveal a Gartland Type III fracture with posterolateral displacement of the distal fragment. Based on this specific displacement pattern, which neurological structure is at the highest risk of injury?
Correct Answer & Explanation
. Anterior interosseous nerve (AIN)
Explanation
In extension-type supracondylar humerus fractures, the direction of displacement of the distal fragment dictates which structures are at risk from the sharp proximal fragment. When the distal fragment is displaced posterolaterally, the proximal fragment is driven anteromedially. This anteromedial spike puts the median nerve (specifically its anterior interosseous nerve branch) and the brachial artery at the highest risk of injury. Conversely, if the distal fragment is displaced posteromedially (the most common pattern), the proximal fragment is driven anterolaterally, putting the radial nerve at risk. The ulnar nerve is most commonly injured in flexion-type supracondylar fractures or iatrogenically during medial pin placement for fixation.
Question 477
Topic: Pediatric Upper Extremity & Spine
A 6-year-old boy is brought to the emergency department after falling from monkey bars. Radiographs confirm a Gartland type III extension-type supracondylar humerus fracture. On physical examination, the hand is well-perfused and pink, with brisk capillary refill, but the radial pulse is absent. What is the most appropriate next step in management?
Correct Answer & Explanation
. Urgent closed reduction and percutaneous pinning (CRPP) in the operating room.
Explanation
The management of a "pink, pulseless" hand in the setting of a displaced pediatric supracondylar humerus fracture is a classic orthopedic emergency scenario. The absence of a palpable pulse is often due to kinking, spasm, or tethering of the brachial artery over the proximal fracture fragment, rather than a complete transection. Because the hand remains pink and well-perfused (indicating adequate collateral circulation), the immediate next step is urgent closed reduction and percutaneous pinning (CRPP) in the operating room. Reduction relieves the tension on the neurovascular bundle, and the pulse often returns. If the hand were "white and pulseless" (ischemic), urgent reduction is still the first step, but if it remains ischemic after reduction, open vascular exploration is mandated. Delaying reduction for advanced imaging (CT angiogram or Doppler) in a pink, pulseless hand is contraindicated as it delays definitive treatment. Skeletal traction is a historical treatment rarely used today for this indication.
Question 478
Topic: Pediatric Upper Extremity & Spine
A 6-year-old boy sustains a Gartland type III extension-type supracondylar humerus fracture after falling from monkey bars. Radiographs demonstrate posteromedial displacement of the distal fracture fragment. Based on this specific displacement pattern, which neurological deficit is most likely to be present on initial physical examination?
Correct Answer & Explanation
. Inability to extend the metacarpophalangeal joints of the fingers
Explanation
In extension-type supracondylar humerus fractures, the direction of displacement of the distal fragment dictates which structures are at risk from the sharp proximal fragment. When the distal fragment is displaced posteromedially, the proximal fragment is driven anterolaterally. This anterolateral spike puts the radial nerve at the highest risk of injury. A radial nerve injury would present as an inability to extend the wrist and the metacarpophalangeal (MCP) joints of the fingers (Option B). Conversely, if the distal fragment is displaced posterolaterally, the proximal fragment is driven anteromedially, putting the median nerve (specifically the anterior interosseous nerve, AIN) at risk. AIN injury presents as an inability to flex the IP joint of the thumb and DIP joint of the index finger (the "OK" sign) (Option A). Options C, D, and E describe ulnar nerve deficits, which are more commonly associated with flexion-type supracondylar fractures or iatrogenic injury during medial pin placement.
Question 479
Topic: Pediatric Upper Extremity & Spine
A 6-year-old boy falls from the monkey bars and sustains an extension-type supracondylar humerus fracture. Radiographs demonstrate that the distal fragment is displaced posteromedially. Based on this specific displacement pattern, which of the following neurological deficits is MOST likely to be observed on physical examination?
Correct Answer & Explanation
. Inability to extend the wrist and digits
Explanation
Correct Answer: B (Inability to extend the wrist and digits)In extension-type supracondylar humerus fractures, the direction of distal fragment displacement dictates which neurovascular structures are at greatest risk due to the relative position of the proximal fragment spike. When the distal fragment displaces posteromedially, the sharp proximal fragment is driven anterolaterally. The radial nerve is located anterolaterally in the distal arm and is therefore the most commonly injured nerve in this specific displacement pattern, leading to an inability to extend the wrist and digits. Conversely, if the distal fragment displaces posterolaterally, the proximal fragment is driven anteromedially, placing the anterior interosseous nerve (AIN) and median nerve at risk (leading to an inability to flex the IP joint of the thumb and DIP of the index finger). Ulnar nerve injuries (numbness in the small finger, weak thumb adduction) are more commonly associated with flexion-type supracondylar fractures or iatrogenic injury during medial pinning.
Question 480
Topic: Pediatric Upper Extremity & Spine
A 15-year-old female presents with a progressive right thoracic curve measuring 55 degrees on Cobb angle, with significant truncal asymmetry. Her Risser sign is 4. She experiences mild back pain but no neurological deficits. What is the most appropriate management for this patient?
Correct Answer & Explanation
. Posterior spinal fusion
Explanation
For adolescent idiopathic scoliosis (AIS), surgical intervention, typically posterior spinal fusion, is indicated for curves greater than 45-50 degrees, especially in patients who are skeletally immature or approaching skeletal maturity (Risser 4 indicates near skeletal maturity). Brace treatment is generally recommended for progressive curves between 25-45 degrees in skeletally immature patients. Observation is for smaller curves or skeletally mature patients with non-progressive curves. Anterior vertebral body tethering is an emerging technique typically for younger, skeletally immature patients with significant growth remaining. Physical therapy is an adjunct but not a primary treatment for significant, progressive curves.
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