This practice set contains high-yield board review questions covering key concepts in Pediatric Lower Extremity. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Question 261
Topic: Pediatric Lower Extremity
A 2-week-old infant is undergoing serial casting for idiopathic clubfoot using the Ponseti method. What is the correct sequence of deformity correction in this technique?
Correct Answer & Explanation
. Equinus, Varus, Adductus, Cavus
Explanation
The Ponseti method corrects deformities in the CAVE sequence: Cavus, Adductus, Varus, and finally Equinus. The cavus is corrected first by supinating the forefoot to align it with the hindfoot.
Question 262
Topic: Pediatric Lower Extremity
An infant is brought to the clinic with bilateral idiopathic clubfoot. The treating orthopedist decides to initiate serial casting using the Ponseti method. What is the correct sequence of deformity correction?
Correct Answer & Explanation
. Cavus, Adductus, Varus, Equinus
Explanation
The Ponseti method follows the CAVE sequence: Cavus, Adductus, Varus, and Equinus. The cavus is corrected first by supinating the forefoot to align it with the hindfoot, followed by correcting adductus and varus simultaneously, and finally equinus is addressed, often requiring an Achilles tenotomy.
Question 263
Topic: Pediatric Lower Extremity
A 12-year-old active boy complains of anterior knee pain exacerbated by jumping. Examination reveals a prominent, tender tibial tubercle. Radiographs show fragmentation of the tibial tubercle apophysis. What is the most appropriate initial management?
Correct Answer & Explanation
. Cylindrical cast immobilization for 6 weeks
Explanation
Osgood-Schlatter disease is a traction apophysitis of the tibial tubercle. It is self-limiting and best managed conservatively with activity modification, stretching, and non-steroidal anti-inflammatory drugs (NSAIDs).
Question 264
Topic: Pediatric Lower Extremity
When utilizing the Ponseti method for the serial casting and correction of idiopathic clubfoot (talipes equinovarus), which of the following sequences correctly represents the order in which the deformity components are addressed?
Correct Answer & Explanation
. Equinus -> Varus -> Adductus -> Cavus
Explanation
The Ponseti method dictates correcting the components of a clubfoot in a strict sequence, classically remembered by the mnemonic CAVE: Cavus, Adductus, Varus, Equinus. The first step involves elevating the first ray to correct the cavus. Next, the forefoot adductus and hindfoot varus are corrected simultaneously by abducting the foot around the fixed talar head. Finally, the equinus is corrected, which often necessitates a percutaneous Achilles tenotomy.
Question 265
Topic: Pediatric Lower Extremity
A 2-year-old boy is brought to the clinic for bilateral bowing of the lower extremities. The physician is trying to differentiate between physiological genu varum and infantile Blount's disease. Measurement of the metaphyseal-diaphyseal (MD) angle of Drennan on standing AP radiographs is performed. Which of the following MD angles most strongly indicates a high likelihood of progression to true infantile Blount's disease?
Correct Answer & Explanation
. 5 degrees
Explanation
The metaphyseal-diaphyseal (MD) angle, described by Drennan, is a critical radiographic parameter to differentiate physiological bowing from infantile tibia vara (Blount's disease). An MD angle greater than 16 degrees has a high positive predictive value for progression to Blount's disease. An angle between 10 and 16 degrees requires close follow-up, while an angle less than 10 degrees is typical for physiologic bowing.
Question 266
Topic: Pediatric Lower Extremity
A 4-year-old boy presents with a recurrent clubfoot deformity after successful initial Ponseti casting and Achilles tenotomy in infancy. The mother notes he drops his foot and walks on the lateral border. Examination reveals dynamic supination during the swing phase of gait. Passive range of motion allows the foot to be brought to neutral. What is the most appropriate management?
Correct Answer & Explanation
. Repeat Ponseti casting followed by a lateral sliding calcaneal osteotomy
Explanation
Dynamic supination during swing phase is a classic presentation of recurrent clubfoot deformity caused by an overactive tibialis anterior pulling against a weakened or lengthened antagonist. Since the deformity is flexible passively, the treatment of choice is transferring the tibialis anterior tendon to the lateral cuneiform to balance the foot dynamically. Bony procedures are reserved for fixed deformities.
Question 267
Topic: Pediatric Lower Extremity
A newborn male is noted to have a limb length discrepancy and deformity of the right lower extremity. Radiographs reveal partial absence of the fibula, anteromedial bowing of the tibia, and a foot with three digits. Which of the following foot deformities is most characteristically associated with this condition?
Correct Answer & Explanation
. Equinovarus
Explanation
Fibular hemimelia is the most common congenital long bone deficiency. It is characterized by partial or complete absence of the fibula, anteromedial bowing of the tibia, absence of lateral rays of the foot, and an equinovalgus foot deformity. Associated findings include femoral shortening (PFFD), cruciate ligament deficiency, and a ball-and-socket ankle joint.
Question 268
Topic: Pediatric Lower Extremity
In the Ponseti method for the management of idiopathic clubfoot, what is the correct sequence of deformity correction?
Correct Answer & Explanation
. Cavus, Adductus, Varus, Equinus
Explanation
The sequence of correction in the Ponseti method is Cavus, Adductus, Varus, and finally Equinus (CAVE). Elevating the first ray corrects the cavus and unlocks the midfoot for further corrective casting.
Question 269
Topic: Pediatric Lower Extremity
A 6-month-old boy with idiopathic clubfoot was successfully treated with the Ponseti method. After serial casting and a percutaneous Achilles tenotomy, his foot is fully corrected. What is the most common cause of relapse in this patient over the next few years?
Correct Answer & Explanation
. Failure to perform a prophylactic tibialis anterior transfer
Explanation
The most common cause of clubfoot relapse following successful correction with the Ponseti method is non-compliance with the foot abduction brace. The brace must be worn full-time initially, then at night until age 3 to 4 years.
Question 270
Topic: Pediatric Lower Extremity
An 8-year-old girl is evaluated for severe in-toeing. On examination, she has 80 degrees of internal hip rotation and 10 degrees of external hip rotation bilaterally. The thigh-foot angle is neutral. What is the most likely diagnosis and its expected natural history?
Correct Answer & Explanation
. Internal tibial torsion; typically resolves by age 10
Explanation
Increased internal hip rotation and decreased external rotation indicate increased femoral anteversion. This condition typically peaks around age 5-6 and spontaneously resolves or compensates by age 10-12 without surgical intervention.
Question 271
Topic: Pediatric Lower Extremity
A neonate is diagnosed with bilateral clubfeet. The parents ask about the specific sequence of deformity correction using the Ponseti method. What is the correct order of correction?
Correct Answer & Explanation
. Cavus, Adductus, Varus, Equinus (CAVE)
Explanation
The Ponseti method corrects clubfoot deformities in a very specific sequence: Cavus (by supinating the forefoot), Adductus, Varus, and finally Equinus (CAVE). Equinus is usually corrected last, often requiring a percutaneous Achilles tenotomy.
Question 272
Topic: Pediatric Lower Extremity
The Ponseti method is the internationally recognized gold standard for the conservative management of idiopathic congenital talipes equinovarus (clubfoot). During the serial casting process, the complex triplanar deformities are sequentially corrected. Which of the following represents the correct order of deformity correction according to the strict Ponseti protocol?
Correct Answer & Explanation
. Cavus, Adductus, Varus, Equinus
Explanation
The Ponseti method requires meticulous serial casting that strictly follows a specific order of correction to accommodate the specific pathoanatomy of the talocalcaneonavicular joint block. The mnemonic CAVE dictates the correct sequence: First, the Cavus is corrected (by elevating the first ray to align the forefoot with the hindfoot). Second, the Adductus and third, the Varus, are corrected simultaneously by abducting the midfoot around the head of the talus. Finally, the Equinus is corrected last (often requiring a percutaneous Achilles tenotomy to achieve 15-20 degrees of dorsiflexion before the final cast is placed). Correcting equinus prematurely leads to a 'rocker-bottom' foot deformity.
Question 273
Topic: Pediatric Lower Extremity
In the Ponseti method for the treatment of congenital idiopathic clubfoot, what is the correct anatomical sequence of deformity correction?
Correct Answer & Explanation
. Cavus, Adductus, Varus, Equinus
Explanation
The Ponseti method requires sequential correction of the clubfoot deformities in a specific order: Cavus (corrected by elevating the first ray), Adductus, Varus, and finally Equinus (often requiring a percutaneous Achilles tenotomy). This sequence is commonly remembered by the mnemonic CAVE.
Question 274
Topic: Pediatric Lower Extremity
A newborn is diagnosed with idiopathic clubfoot (talipes equinovarus) and is started on the Ponseti method of serial casting. What is the correct sequence of deformity correction, and which deformity must be addressed first?
Correct Answer & Explanation
. Equinus is corrected first by percutaneous tenotomy
Explanation
In the Ponseti method (C-A-V-E sequence), the Cavus deformity must be corrected first by supinating the forefoot and elevating the first ray. This aligns the forefoot with the hindfoot, unlocking the midtarsal joint for subsequent abduction.
Question 275
Topic: Pediatric Lower Extremity
When utilizing the Ponseti method for the conservative management of idiopathic clubfoot, what is the anatomically correct sequence for correcting the components of the deformity?
Correct Answer & Explanation
. Cavus, Adductus, Varus, Equinus
Explanation
The Ponseti method dictates a strict sequential correction of the clubfoot deformities, easily remembered by the acronym CAVE: Cavus (by supinating the forefoot), Adductus, Varus, and finally Equinus (usually requiring a percutaneous Achilles tenotomy).
Question 276
Topic: Pediatric Lower Extremity
During the Ponseti method for the correction of idiopathic clubfoot (talipes equinovarus), the deformities are systematically corrected through a series of specific casts. What is the correct sequence of deformity correction using this technique?
Correct Answer & Explanation
. Cavus, Adductus, Varus, Equinus
Explanation
The mnemonic for the Ponseti method correction sequence is CAVE: Cavus (corrected first by elevating the first ray to align the forefoot with the hindfoot), Adductus, Varus, and finally Equinus (which often requires a percutaneous Achilles tenotomy to fully correct once the talonavicular joint is reduced).
Question 277
Topic: Pediatric Lower Extremity
The Ponseti method is the gold standard for the treatment of idiopathic clubfoot (talipes equinovarus). According to this technique, the serial casting process follows a specific order of deformity correction (CAVE). What is the first component of the deformity that must be corrected?
Correct Answer & Explanation
. Equinus
Explanation
In the Ponseti method, the deformities are corrected in a specific sequence summarized by the acronym CAVE: Cavus, Adductus, Varus, Equinus. The cavus is corrected first by elevating the first ray (supinating the forefoot) to align it with the hindfoot. Only then is the entire foot abducted around the head of the talus to correct adductus and varus.
Question 278
Topic: Pediatric Lower Extremity
An infant is diagnosed with idiopathic clubfoot (talipes equinovarus) and treatment with the Ponseti method is initiated. According to this standardized casting technique, what is the correct sequence of deformity correction?
Correct Answer & Explanation
. Equinus, Varus, Adductus, Cavus
Explanation
The Ponseti method systematically corrects clubfoot deformities in the specific order of the acronym CAVE: Cavus, Adductus, Varus, and finally Equinus. Equinus is typically corrected last, often requiring a percutaneous Achilles tenotomy.
Question 279
Topic: Pediatric Lower Extremity
In the Ponseti method for correcting idiopathic clubfoot, what is the correct anatomical sequence of deformity correction?
Correct Answer & Explanation
. Equinus, Varus, Adductus, Cavus
Explanation
The Ponseti method follows a strict, step-wise sequence for clubfoot correction, easily remembered by the acronym CAVE: Cavus (corrected by elevating the first ray), Adductus, Varus (adductus and varus corrected simultaneously by abducting the midfoot with counter-pressure on the lateral head of the talus), and finally Equinus (corrected last, often requiring a percutaneous Achilles tenotomy).
Question 280
Topic: Pediatric Lower Extremity
An infant is born with bilateral idiopathic clubfeet (talipes equinovarus). The orthopedic surgeon elects to begin treatment using the Ponseti method of serial casting. What is the correct sequence of deformity correction in this method?
Correct Answer & Explanation
. Adduction, Cavus, Varus, Equinus
Explanation
The Ponseti method requires sequential correction of the clubfoot deformities using the CAVE mnemonic: Cavus, Adductus, Varus, and finally Equinus. The first step involves elevating the first ray to correct the forefoot cavus, which aligns the forefoot with the midfoot.
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