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 1681
Topic: 4. Pediatrics
The parents of a 15-month-old child report that he is not yet walking. Further evaluation, rather than reassurance and observation, should be conducted if the child is not performing what other activity?
Correct Answer & Explanation
. Sitting
Explanation
A child not ambulating at age 15 months is still within normal limits. The child should be able to sit by age 9 months. The remaining milestones listed are reached later in development.
Question 1682
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?
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 1683
Topic: Pediatric Upper Extremity & Spine
A 12-year-old premenarchal female (Risser stage 0) is diagnosed with adolescent idiopathic scoliosis (AIS). Standing posteroanterior radiographs reveal a right thoracic curve measuring 34 degrees. What is the most appropriate initial, evidence-based management strategy to prevent curve progression to surgical magnitude?
Correct Answer & Explanation
. Observation with repeat radiographs every 12 months
Explanation
According to the Bracing in Adolescent Idiopathic Scoliosis Trial (BrAIST), TLSO bracing is indicated and highly effective for skeletally immature patients (Risser 0-2, premenarchal) with curves between 25 and 45 degrees. Bracing significantly decreases the progression of high-risk curves to the surgical threshold (generally >50 degrees).
Question 1684
Topic: Pediatric Upper Extremity & Spine
A 13-year-old premenarchal female presents for routine evaluation of adolescent idiopathic scoliosis. Standing posteroanterior radiographs demonstrate a right thoracic curve measuring 35 degrees using the Cobb method. Her Risser stage is 1. What is the most appropriate management to halt curve progression?
Correct Answer & Explanation
. Thoracolumbosacral orthosis (TLSO) bracing for 16-23 hours per day
Explanation
The indications for bracing in Adolescent Idiopathic Scoliosis (AIS) include a growing child (Risser stage 0-2, premenarchal or < 1 year postmenarchal) with a progressive curve between 25 and 45 degrees. The goal of bracing is to halt curve progression and prevent the need for surgery. Bracing for 16-23 hours per day (dose-dependent) with a rigid TLSO has been shown in the BRAIST trial to significantly decrease the rate of progression to the surgical threshold.
Question 1685
Topic: 4. Pediatrics
What is the primary indication for performing an arthroscopic synovectomy on a patient with hemophilia that is the result of factor VIII deficiency?
Correct Answer & Explanation
. Recurrent joint bleeding despite optimal medical management
Explanation
DISCUSSION: Improved medical management has changed musculoskeletal outcomes for individuals with hemophilia. Patients with severe hemophilia receiving prophylactic administration of factor VIII may never develop a target joint that requires further orthopaedic intervention. Patients with moderate hemophilia and those patients with severe hemophilia not receiving prophylactic treatment will still develop joints that have recurrent hemarthroses. When recurrent hemarthrosis continues despite optimal medical management, synovectomy is indicated. While synovectomy is predictable in its ability to decrease joint bleeding, it does not necessarily improve joint range of motion or prevent the development of hemophilic arthropathy over time. It will not reverse articular damage to the joint once it has developed. REFERENCES: Dunn AL, Busch MT, Wyly JB; et al: Arthroscopic synovectomy for hemophilic joint disease in a pediatric population. J Pediatr Orthop 2004;24:414-426. Journeycake JM, Miller KL, Anderson AM, et al: Arthroscopic synovectomy in children and adolescents with hemophilia. J Pediatr Hematol Oncol 2003;25:726-731.
Question 1686
Topic: 4. Pediatrics
A 7-year-old boy is seen in the emergency department with an isolated and displaced supracondylar humerus fracture and absent radial and ulnar pulses. Despite a moderately painful attempt at realignment, examination reveals that his hand remains pulseless. What is the next most appropriate step in management?
Correct Answer & Explanation
. Perform closed reduction and pinning in the OR and reassess the vascular status.
Explanation
DISCUSSION: Displaced supracondylar humerus fractures in children may have associated vascular compromise. Decreased blood flow may be due to vessel injury, entrapment within the fracture site, kinking from fracture displacement, or from vessel spasm. Optimal initial treatment in the emergency department includes gentle realignment of the limb and vascular assessment. Angiography is not required in isolated injuries as the level of the vessel compromise is always at the site of the fracture. When blood flow is not restored, the next best step in treatment is to proceed urgently to the operating room. A formal closed reduction and pinning is performed, and then the vascular status is reassessed. Exploration and vascular repair is required if the hand is cool, white, and without pulses. REFERENCES: Ay S, Akinci M, Kamiloglu S, et al: Open reduction of displaced pediatric supracondylar humeral fractures through the anterior cubital approach. J Pediatr Orthop 2005;25:149-153. 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. Dormans JP, Squillante R, Sharf H: Acute neurovascular complications with supracondylar humerus fractures in children. J Hand Surg Am 1995;20:1-4.
Question 1687
Topic: 4. Pediatrics
A 14-year-old boy presents with severe ankle pain after twisting his leg while sliding into a base. Radiographs reveal a fracture of the anterolateral distal tibial epiphysis. What is the precise pathomechanics responsible for this specific fracture pattern?
Correct Answer & Explanation
. Avulsion by the anterior inferior tibiofibular ligament during an external rotation force
Explanation
The juvenile Tillaux fracture is a Salter-Harris Type III fracture of the anterolateral aspect of the distal tibial epiphysis. It uniquely occurs in adolescents because the distal tibial physis closes asymmetrically: from central, to anteromedial, to posteromedial, and finally the anterolateral portion. An external rotation force causes the strong anterior inferior tibiofibular ligament (AITFL) to avulse the unfused anterolateral epiphysis.
Question 1688
Topic: 4. Pediatrics
A 14-year-old boy presents with an ankle injury after a twisting fall. Radiographs reveal an isolated Salter-Harris III fracture of the anterolateral distal tibial epiphysis. What is the primary pathomechanical mechanism of this specific fracture pattern?
Correct Answer & Explanation
. Avulsion by the anterior inferior tibiofibular ligament (AITFL) due to external rotation
Explanation
A juvenile Tillaux fracture is a Salter-Harris III fracture of the anterolateral distal tibia. It occurs because the distal tibial physis closes in a predictable pattern: central, then medial, and finally lateral. External rotation of the foot causes the intact AITFL to avulse the anterolateral epiphysis, which is the last portion of the physis to fuse.
Question 1689
Topic: Pediatric Upper Extremity & Spine
A 14-year-old girl with adolescent idiopathic scoliosis presents for evaluation. Standing radiographs show a right thoracic curve of 55°, a left lumbar curve of 35°, and a proximal thoracic curve of 20°. On side-bending films, the thoracic curve reduces to 30°, the lumbar curve to 15°, and the proximal thoracic to 10°. The apical lumbar vertebra is L2, and the center sacral vertical line (CSVL) touches the medial border of the left L2 pedicle. Sagittal T5-T12 kyphosis is +25°. Based on the Lenke classification, what is the correct curve type and modifier?
Correct Answer & Explanation
. 1AN
Explanation
The patient has a Lenke 1 (Main Thoracic) curve. The main thoracic curve is structural (>25° on bending). The lumbar curve is non-structural as it bends out to <25° (15°). The proximal thoracic is also non-structural (<25° on bending). The lumbar modifier is B because the CSVL falls between the lateral margin of the apical vertebral body and the medial border of the pedicle. The sagittal modifier is N (Normal, 10°-40°). Therefore, the classification is 1BN.
Question 1690
Topic: Pediatric Upper Extremity & Spine
In the Bracing in Adolescent Idiopathic Scoliosis Trial (BRAIST), what factor was most strongly correlated with the prevention of curve progression to a surgical magnitude (>=50 degrees)?
Correct Answer & Explanation
. Dose-response hours of brace wear
Explanation
The BRAIST trial demonstrated a strong dose-response relationship between brace wear and success. Patients who wore the brace for more than 12.9 hours per day had success rates exceeding 90%.
Question 1691
Topic: 4. Pediatrics
A 3-year-old child presents with a congenital scoliosis. Radiographs demonstrate a unilateral unsegmented bar with fully segmented contralateral hemivertebrae at the same levels. What is the most appropriate management?
Correct Answer & Explanation
. Observation until age 10
Explanation
A unilateral unsegmented bar with contralateral hemivertebrae is the most highly progressive congenital curve pattern, often progressing 5 to 10 degrees per year. Early definitive in situ fusion is indicated to prevent severe deformity.
Question 1692
Topic: Pediatric Upper Extremity & Spine
A 16-year-old girl undergoes a posterior spinal fusion from T4 to L3 for adolescent idiopathic scoliosis (Lenke 1A). On postoperative day 4, she develops severe bilious emesis, abdominal distension, and weight loss. Upright abdominal films show a dilated stomach and proximal duodenum with abrupt cutoff. What is the anatomic mechanism of this complication?
Correct Answer & Explanation
. Compression of the duodenum between the superior mesenteric artery and the aorta
Explanation
Superior Mesenteric Artery (SMA) syndrome is a known complication following scoliosis correction. Lengthening of the spine alters the angle of the SMA, compressing the third portion of the duodenum against the aorta.
Question 1693
Topic: Pediatric Upper Extremity & Spine
A 12-year-old girl with adolescent idiopathic scoliosis has a 35-degree right thoracic curve. Her Risser stage is 1. Her menarche occurred 2 months ago. What is the most appropriate management?
Correct Answer & Explanation
. Observation with radiographs in 6 months
Explanation
In a growing child (Risser 0-2) with an AIS curve between 25 and 45 degrees, bracing is indicated to halt progression. Given her recent menarche and Risser 1 status, she has significant growth remaining, making bracing the gold standard.
Question 1694
Topic: Pediatric Upper Extremity & Spine
A 12-year-old premenarcheal female presents with a right thoracic curve of 32 degrees.
Radiographs show open triradiate cartilages and a Risser stage of 0. What is the most appropriate management based on the Bracing in Adolescent Idiopathic Scoliosis Trial (BrAIST)?
Correct Answer & Explanation
. Observation with radiographs in 6 months
Explanation
The BrAIST study demonstrated the efficacy of bracing in preventing curve progression to the surgical threshold (>50 degrees) in patients with AIS who are still growing (Risser 0-2) with curves between 25 and 40 degrees. A dose-response curve showed optimal results with >18 hours of wear per day.
Question 1695
Topic: Pediatric Hip
Figure 36 shows the radiograph of a 14-year-old boy who has been treated in the past for Perthes’ disease with an abduction brace. He now has hip pain that limits his activity, and nonsteroidal anti-inflammatory drugs have failed to provide relief. What is the most appropriate treatment?
Correct Answer & Explanation
. Shelf acetabuloplasty
Explanation
Several authors have reported good success in relieving pain with shelf acetabuloplasty. This patient’s Perthes’ disease is in the healed phase; therefore, proximal femoral varus and Salter innominate osteotomies aimed at improving containment are not indicated. The medial one half of the patient’s femoral head is markedly deformed, and rotating it into a weight-bearing position with proximal femoral valgus osteotomy is unlikely to relieve pain. Hip arthrodesis can always be performed as a salvage procedure if the shelf acetabuloplasty fails.
Question 1696
Topic: 4. Pediatrics
A 14-year-old male complains of right ankle pain after a skateboarding fall. Radiographs reveal a Salter-Harris III fracture of the anterolateral aspect of the distal tibia. This specific fracture (juvenile Tillaux) is possible due to the asymmetric closure pattern of the distal tibial physis. What is the predictable chronological sequence of this physeal closure?
Correct Answer & Explanation
. Central, then medial, then lateral
Explanation
The distal tibial physis closes over a period of 18 months in a predictable sequence: central, then medial, and finally lateral. Because the anterolateral portion is the last to fuse, external rotation forces during this 18-month window pull on the AITFL, avulsing the unfused anterolateral epiphysis, resulting in a juvenile Tillaux fracture (Salter-Harris III).
Question 1697
Topic: 4. Pediatrics
A 14-year-old male presents with lateral ankle pain after a twisting injury playing soccer. Radiographs and a subsequent CT scan demonstrate a displaced Salter-Harris III fracture of the anterolateral aspect of the distal tibial epiphysis. What is the primary deforming force responsible for this specific fracture pattern?
Correct Answer & Explanation
. Anterior inferior tibiofibular ligament (AITFL)
Explanation
A Tillaux fracture is a Salter-Harris type III fracture of the anterolateral distal tibial epiphysis. It occurs in adolescents whose distal tibial physis has begun to close (which closes central to medial, then lateral). The avulsion is caused by tension from the anterior inferior tibiofibular ligament (AITFL) during external rotation forces.
Question 1698
Topic: 4. Pediatrics
A 13-year-old female sustains a triplane ankle fracture. Which of the following best describes the classical anatomical planes of injury in the three parts of this fracture?
A triplane fracture is a unique pediatric fracture occurring during the transitional phase of physeal closure. It classically involves a fracture line in the sagittal plane through the epiphysis, a transverse plane through the physis, and a coronal plane through the distal tibial metaphysis. On AP radiographs, it mimics a Salter-Harris III fracture, while on lateral radiographs, it mimics a Salter-Harris II fracture.
Question 1699
Topic: Pediatric Upper Extremity & Spine
A 6-year-old boy presents with a completely displaced extension-type supracondylar fracture of the humerus.
Which of the following clinical deficits represents the most common nerve injury associated with this specific fracture pattern?
Correct Answer & Explanation
. Inability to flex the interphalangeal joint of the thumb and distal interphalangeal joint of the index finger.
Explanation
The anterior interosseous nerve (AIN) is the most commonly injured nerve in extension-type supracondylar humerus fractures. Injury to the AIN manifests as weakness or inability to flex the interphalangeal joint of the thumb (flexor pollicis longus) and the distal interphalangeal joint of the index finger (flexor digitorum profundus), resulting in an inability to form the 'OK' sign.
Question 1700
Topic: Pediatric Upper Extremity & Spine
A 5-year-old boy presents with a Gartland type III extension-type supracondylar humerus fracture. Which specific physical examination finding is the hallmark of the most common nerve injury associated with this fracture pattern?
Correct Answer & Explanation
. Inability to flex the distal interphalangeal joint of the index finger
Explanation
The anterior interosseous nerve (AIN) is the most commonly injured nerve in extension-type supracondylar humerus fractures. The AIN is a purely motor branch of the median nerve that innervates the flexor pollicis longus (FPL), the flexor digitorum profundus (FDP) to the index and middle fingers, and the pronator quadratus. Injury results in the inability to form an 'OK' sign, manifesting as an inability to flex the IP joint of the thumb and the DIP joint of the index finger.
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