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Pediatric Upper Extremity & Spine MCQs

Practice Set 31 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 601

Topic: Pediatric Upper Extremity & Spine
A newborn is noted to have severe bilateral radial deviation of the wrists, absent thumbs, and an absent radius on radiographs. An echocardiogram reveals an atrial septal defect (ASD). Which of the following syndromes is most likely?
. TAR syndrome (Thrombocytopenia-Absent Radius)
. Holt-Oram syndrome
. Fanconi anemia
. VACTERL association
. Cornรฉlia de Lange syndrome

Correct Answer & Explanation

. Holt-Oram syndrome

Explanation

Holt-Oram syndrome is an autosomal dominant condition characterized by radial longitudinal deficiency (often bilateral with absent thumbs) and congenital heart defects, most commonly an ASD or VSD. TAR syndrome typically features an absent radius but importantly has present thumbs, distinguishing it from other causes of radial clubhand.

Question 602

Topic: Pediatric Upper Extremity & Spine

A 6-year-old boy falls on an outstretched hand and sustains an extension-type supracondylar humerus fracture. Upon neurologic examination, he is unable to flex the interphalangeal joint of his thumb and the distal interphalangeal joint of his index finger. Which of the following nerves is most likely injured?

. Radial nerve
. Ulnar nerve
. Anterior interosseous nerve
. Posterior interosseous nerve
. Musculocutaneous nerve

Correct Answer & Explanation

. Anterior interosseous nerve

Explanation

Anterior interosseous nerve (AIN) injury is the most common neurologic complication in extension-type supracondylar humerus fractures. It presents clinically as an inability to form the "OK" sign due to weakness of the flexor pollicis longus and flexor digitorum profundus.

Question 603

Topic: Pediatric Upper Extremity & Spine

A 13-year-old premenarchal female presents for evaluation of a spinal deformity. Radiographs reveal a right thoracic curve with a Cobb angle of 32 degrees. Her Risser stage is 0. What is the most appropriate management?

. Observation with radiographs in 6 months
. Schroth physical therapy
. Thoracolumbosacral orthosis (TLSO) bracing
. Posterior spinal fusion
. Vertebral body tethering

Correct Answer & Explanation

. Thoracolumbosacral orthosis (TLSO) bracing

Explanation

TLSO bracing is indicated in skeletally immature patients (Risser 0-2, premenarchal) with adolescent idiopathic scoliosis who have a curve magnitude between 25 and 45 degrees. Bracing has been shown to significantly decrease the risk of curve progression to surgical magnitude.

Question 604

Topic: Pediatric Upper Extremity & Spine

A 6-year-old boy presents with a displaced extension-type supracondylar humerus fracture. His hand is pink and well-perfused, but he cannot flex the interphalangeal joint of his thumb or the distal interphalangeal joint of his index finger. Which of the following nerve structures is most likely injured?

. Ulnar nerve
. Radial nerve
. Anterior interosseous nerve
. Posterior interosseous nerve
. Musculocutaneous nerve

Correct Answer & Explanation

. Anterior interosseous nerve

Explanation

The anterior interosseous nerve (AIN) is the most commonly injured nerve in extension-type supracondylar humerus fractures. It innervates the flexor pollicis longus and the flexor digitorum profundus to the index and middle fingers.

Question 605

Topic: Pediatric Upper Extremity & Spine

A 6-year-old boy sustains a completely displaced, extension-type supracondylar humerus fracture. On initial presentation, his hand is pulseless but pink, warm, and has a capillary refill time of 1.5 seconds. After successful closed reduction and percutaneous pinning, the radial pulse remains unpalpable, but the hand remains pink and warm with excellent capillary refill. What is the most appropriate next step in management?

. Immediate exploration of the brachial artery
. Vascular surgery consultation for an emergent angiogram
. Observation and hospital admission for close monitoring
. Immediate release of the anterior forearm fascia
. Removal of the pins and transition to open reduction

Correct Answer & Explanation

. Observation and hospital admission for close monitoring

Explanation

A 'pulseless but pink' hand after anatomic closed reduction and pinning of a supracondylar humerus fracture is an indication for observation. As long as perfusion is clinically adequate, collateral circulation is sufficient, and the pulse often returns within a few days.

Question 606

Topic: Pediatric Upper Extremity & Spine

A 12-year-old premenarchal female presents with Adolescent Idiopathic Scoliosis (AIS). Her standing PA spine radiograph reveals a right thoracic curve of 34 degrees. Her Risser stage is 0. According to the standard guidelines, what is the most appropriate management?

. Observation with repeat radiographs in 6 months
. Physical therapy focusing on core strengthening
. Thoracolumbosacral orthosis (TLSO) brace wear for 16-23 hours daily
. Posterior spinal fusion with pedicle screw instrumentation
. Anterior vertebral body tethering (AVBT)

Correct Answer & Explanation

. Thoracolumbosacral orthosis (TLSO) brace wear for 16-23 hours daily

Explanation

Bracing is indicated for a growing child (Risser 0-2, premenarchal) with a scoliotic curve between 25 and 45 degrees. A TLSO worn for at least 16-18 hours per day is the standard of care to halt progression.

Question 607

Topic: Pediatric Upper Extremity & Spine
A 6-year-old boy presents with a completely displaced (Gartland type III) supracondylar humerus fracture. On initial exam, his hand is pale and pulseless. Following closed reduction and percutaneous pinning, the hand becomes warm and pink with a capillary refill of 2 seconds, but the radial pulse remains unpalpable. What is the most appropriate next step in management?
. Immediate vascular exploration
. Perform a CT angiogram of the upper extremity
. Open reduction and internal fixation to decompress the artery
. Observation and close clinical monitoring
. Remove the pins and cast the arm in extension

Correct Answer & Explanation

. Observation and close clinical monitoring

Explanation

In a pediatric supracondylar humerus fracture presenting with a 'pink, pulseless' hand after a successful anatomical reduction and stabilization, the extremity is well-perfused via collateral circulation. The standard of care is observation and close monitoring, as routine vascular exploration is not indicated if perfusion is adequate.

Question 608

Topic: Pediatric Upper Extremity & Spine
A neonate is evaluated for bilateral radial deviation of the hands. Radiographs reveal complete absence of the radii bilaterally. However, the child has well-formed, pentadactyl hands with fully functional thumbs bilaterally. Laboratory evaluation is notable for a profoundly low platelet count. This clinical picture is pathognomonic for which of the following syndromes?
. Fanconi anemia
. Holt-Oram syndrome
. VACTERL association
. TAR (Thrombocytopenia-Absent Radius) syndrome
. Apert syndrome

Correct Answer & Explanation

. TAR (Thrombocytopenia-Absent Radius) syndrome

Explanation

TAR (Thrombocytopenia-Absent Radius) syndrome is classically characterized by bilateral absence of the radius combined with thrombocytopenia. A pathognomonic and differentiating feature of TAR syndrome is that the thumb is uniformly present and often functional, unlike other radial longitudinal deficiencies (such as Fanconi anemia, Holt-Oram syndrome, and VACTERL association) where the thumb is typically absent or severely hypoplastic.

Question 609

Topic: Pediatric Upper Extremity & Spine
A newborn is evaluated for a right radial clubhand and an absent thumb. To rule out the most life-threatening associated condition in this patient, which of the following screening tests must be obtained?
. Renal ultrasound
. Echocardiogram
. Chromosomal breakage analysis with diepoxybutane (DEB)
. Radiographs of the cervical spine
. Bone marrow aspiration

Correct Answer & Explanation

. Chromosomal breakage analysis with diepoxybutane (DEB)

Explanation

Radial longitudinal deficiency is associated with several syndromes, including VATER/VACTERL, Holt-Oram, TAR, and Fanconi anemia. Fanconi anemia is the most life-threatening of these due to its high risk of aplastic anemia and leukemia. It is diagnosed via chromosomal breakage testing induced by diepoxybutane (DEB) or mitomycin C. While echocardiogram and renal ultrasounds are also part of the workup for VACTERL and Holt-Oram, ruling out Fanconi anemia is paramount.

Question 610

Topic: Pediatric Upper Extremity & Spine

A newborn is evaluated for a right radial longitudinal deficiency. Physical exam shows an absent right thumb and radius. Complete blood counts are entirely normal at birth, but the pediatrician is concerned about a condition that commonly presents with aplastic anemia later in childhood. Which of the following tests is used to definitively diagnose this genetic condition?

. Chromosomal breakage test with diepoxybutane (DEB)
. Bone marrow aspirate showing ringed sideroblasts
. Flow cytometry for CD55 and CD59
. Hemoglobin electrophoresis
. Whole exome sequencing for TBX5 mutation

Correct Answer & Explanation

. Chromosomal breakage test with diepoxybutane (DEB)

Explanation

The patient is suspected of having Fanconi anemia, an autosomal recessive disorder characterized by radial ray anomalies (absent radius and thumb) and progressive bone marrow failure. The definitive diagnostic test is chromosomal breakage analysis using clastogenic agents like diepoxybutane (DEB) or mitomycin C. Normal complete blood counts at birth are common, as pancytopenia typically develops between ages 5 and 10.

Question 611

Topic: Pediatric Upper Extremity & Spine

A neonate is evaluated for bilateral congenital forearm anomalies. Radiographs demonstrate bilateral absent radii, but both thumbs are present and well-formed. Which of the following diagnostic tests is the most urgent next step in the workup of this patient?

. Chromosomal breakage analysis
. Echocardiogram
. Complete blood count
. Renal ultrasound
. Skeletal survey for associated lower extremity anomalies

Correct Answer & Explanation

. Complete blood count

Explanation

This presentation is highly characteristic of Thrombocytopenia-Absent Radius (TAR) syndrome. A key distinguishing feature of TAR syndrome compared to Fanconi anemia and Holt-Oram syndrome is that the thumbs are present despite the absent radii. A complete blood count is crucial to evaluate for thrombocytopenia, which can be life-threatening in early infancy. Fanconi anemia (requires chromosomal breakage analysis) presents with absent radii AND absent thumbs. Holt-Oram syndrome (requires echocardiogram) involves heart defects and variable radial/thumb deficiencies.

Question 612

Topic: Pediatric Upper Extremity & Spine

A 12-year-old girl with adolescent idiopathic scoliosis (AIS) presents with a right thoracic curve. Which of the following factors is the most reliable predictor of future curve progression in this patient?

. Magnitude of the curve at initial presentation
. Presence of back pain
. Family history of surgical intervention for scoliosis
. A left lumbar compensatory curve
. Apical vertebral rotation of 10 degrees

Correct Answer & Explanation

. Magnitude of the curve at initial presentation

Explanation

The two most important overall predictors of curve progression in adolescent idiopathic scoliosis (AIS) are the magnitude of the curve at the time of diagnosis and the growth potential of the patient (indicated by age, menarchal status, and Risser sign). A larger curve magnitude at initial presentation correlates directly with a higher risk of relentless progression.

Question 613

Topic: Pediatric Upper Extremity & Spine

In a 12-year-old female with Adolescent Idiopathic Scoliosis (AIS), which of the following combinations of clinical and radiographic parameters is associated with the highest statistical risk of curve progression?

. Risser 4, curve of 35 degrees, pre-menarchal
. Risser 0, curve of 30 degrees, open triradiate cartilage
. Risser 2, curve of 15 degrees, post-menarchal
. Risser 5, curve of 45 degrees, Sanders stage 7
. Risser 1, curve of 20 degrees, closed triradiate cartilage

Correct Answer & Explanation

. Risser 0, curve of 30 degrees, open triradiate cartilage

Explanation

The risk of curve progression in AIS is highest during the adolescent peak height velocity. Markers of significant remaining skeletal growth include a low Risser stage (0), open triradiate cartilage, and pre-menarchal status. A curve of 30 degrees combined with Risser 0 and an open triradiate cartilage indicates a nearly 100% risk of progression.

Question 614

Topic: Pediatric Upper Extremity & Spine
A 15-day-old boy presents with deformity of the right hand. The boy was delivered prematurely and underwent an urgent arterial switch for transposition of great vessels. The patient is in stable condition. He has a radial club hand, and because the radial head cannot be palpated, total absence of radius is suspected. The thumb is absent and the index finger has camptodactyly. The forearm is short compared to the left side, and the patient flexes his elbow upon stimulation. Spontaneous finger motion is also present. A thorough physical examination is performed and a set of investigations is ordered. The results are as follows: complete blood count 10,000 mcu/L; platelet 254ร—10^3 mcu/L; neutrophils 50%; Hb 14.2 mg/dL; lymphocytes 40%; Hct 45; and monocytes 10%. No renal abnormalities were noted on ultrasonogram of the abdomen. A radiograph of the spine is normal. Diagnosis is:
. Vertebral defects, anal atresia, tracheoesophageal fistula with esophageal atresia, and radial and renal anomalies (VATER)
. Abnormalities of vertebrae, anus, cardiovascular tree, trachea, esophagus, renal system, and limb buds (VACTERL)
. Thrombocytopenia absent radii (TAR) syndrome
. Holt-Oram syndrome
. Fanconi's anemia

Correct Answer & Explanation

. Holt-Oram syndrome

Explanation

The patient has a radial club hand with a cardiac defect. Because the spine radiograph is normal, the diagnosis cannot be VATER or VACTERL anomaly as both involve vertebrae. Blood work up is normal, making this diagnosis Holt-Oram syndrome.

Question 615

Topic: Pediatric Upper Extremity & Spine

The principal abnormality associated with Holt-Oram syndrome is:

. Platelet deficiency
. C ardiac defects
. Pancytopenia
. Malignancy
. Vertebral defects

Correct Answer & Explanation

. C ardiac defects

Explanation

Holt-Oram syndrome is associated with cardiac defects. The most common defect is aldosterone secretion.

Question 616

Topic: Pediatric Upper Extremity & Spine
A 15-day-old boy presents with deformity of the right hand. The boy was delivered prematurely and underwent an urgent arterial switch for transposition of great vessels. The patient is in stable condition. He has a radial club hand, and because the radial head cannot be palpated, total absence of radius is suspected. The thumb is absent and the index finger has camptodactyly. The forearm is short compared to the left side, and the patient flexes his elbow upon stimulation. Spontaneous finger motion is also present. A thorough physical examination is performed and a set of investigations is ordered. The results are as follows: complete blood count 10,000 mcu/L; platelet 254ร—10^3 mcu/L; neutrophils 50%; Hb 14.2 mg/dL; lymphocytes 40%; Hct 45; and monocytes 10%. No renal abnormalities were noted on ultrasonogram of the abdomen. A radiograph of the spine is normal. The next step in the management of the radial club hand is:
. Stretching
. Soft-tissue distraction
. Radialization
. Centralization
. Pollicization

Correct Answer & Explanation

. Stretching

Explanation

For the first 6 to 9 months, parents and therapists perform passive stretching. Serial casting and splinting may also be used. Sometimes, preoperative soft-tissue distraction is performed, usually before a wrist stabilization procedure.

Question 617

Topic: Pediatric Upper Extremity & Spine
A 5-year-old child falls from monkey bars and sustains a completely displaced (Gartland Type III) extension-type supracondylar humerus fracture. On examination, the radial pulse is absent, but the hand is warm, pink, and has capillary refill under 2 seconds. What is the most appropriate next step in management?
. Immediate open exploration of the brachial artery
. CT angiography of the upper extremity
. Closed reduction and percutaneous pinning
. Observation and elevation of the arm
. Immediate fasciotomy of the forearm

Correct Answer & Explanation

. Closed reduction and percutaneous pinning

Explanation

In a 'pulseless, pink' hand associated with a supracondylar humerus fracture, the initial treatment is emergent closed reduction and percutaneous pinning. Often, the pulse returns once the fracture is reduced, and vascular exploration is not indicated unless the hand becomes cool and pale.

Question 618

Topic: Pediatric Upper Extremity & Spine
A 6-year-old girl falls onto an outstretched hand, sustaining a completely displaced, extension-type supracondylar humerus fracture (Gartland Type III). Which nerve is anatomically at the greatest risk of injury and most commonly injured in this specific fracture pattern?
. Radial nerve
. Ulnar nerve
. Anterior interosseous nerve (AIN)
. Posterior interosseous nerve (PIN)
. Musculocutaneous nerve

Correct Answer & Explanation

. Anterior interosseous nerve (AIN)

Explanation

In extension-type supracondylar humerus fractures, the proximal fragment is displaced anteriorly, placing the anterior interosseous nerve (AIN, a branch of the median nerve) at the highest risk. Clinically, this manifests as an inability to flex the IP joint of the thumb and the DIP joint of the index finger (a positive 'OK' sign test). Note: In flexion-type fractures, the ulnar nerve is more commonly injured.

Question 619

Topic: Pediatric Upper Extremity & Spine

A 45-year-old male is involved in a motor vehicle collision resulting in a spinal cord injury. Neurological examination reveals preserved motor function below the neurological level of injury, and more than half of the key muscles below the neurological level have a muscle grade of 3 or greater. Sensory function is preserved. Which ASIA Impairment Scale (AIS) grade does this represent?

. AIS A
. AIS B
. AIS C
. AIS D
. AIS E

Correct Answer & Explanation

. AIS D

Explanation

The ASIA Impairment Scale (AIS) D is defined as motor incomplete, with motor function preserved below the neurological level, and at least half of the key muscles below the neurological level of injury having a muscle grade of 3 or greater. AIS C has less than half with grade 3 or greater. AIS B is sensory incomplete (no motor function), and AIS A is complete (no motor or sensory in S4-S5).

Question 620

Topic: Pediatric Upper Extremity & Spine
A 6-year-old boy presents to the emergency department following a fall from monkey bars. Radiographs reveal an extension-type Gartland III supracondylar humerus fracture. After closed reduction and percutaneous pinning, the patient's radial pulse is absent, but the hand is pink, warm, and has a capillary refill time of less than 2 seconds. What is the most appropriate next step in management?
. Observation with close neurovascular monitoring
. Immediate exploration of the brachial artery
. Removal of the pins and extension of the elbow to 20 degrees
. CT angiography of the upper extremity
. Prophylactic forearm fasciotomy

Correct Answer & Explanation

. Observation with close neurovascular monitoring

Explanation

A pulseless, pink, and well-perfused hand following reduction and pinning of a supracondylar humerus fracture should be observed, as collateral circulation is adequate. Arterial exploration is strictly indicated only if the hand is pulseless, pale, and poorly perfused (ischemic) after reduction.

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