Pediatric Orthopaedics Practice Questions

Q: What is the commonest congenital deformity?

Congenital club foot. **Explanation:** **Congenital Clubfoot (CTEV - Congenital Talipes Equinovarus)** is the most common congenital musculoskeletal deformity, occurring in approximately 1 to 2 per 1,000 live births. It is characterized by a complex three-dimensional deformity involving four components: **C**avus, **A**dduction (forefoot), **V**arus (heel), and **E**quinus (ankle). The high incidence and its classic presentation make it a frequent topic in postgraduate entrance exams. **Analysis of Options:** * **Congenital Clubfoot (Correct):** Its high prevalence (1:1000) and well-documented genetic/environmental etiology make it the most frequent among the listed options. * **Congenital Club Hand:** This is a longitudinal radial deficiency. While significant, it is much rarer than CTEV, occurring in approximately 1 in 30,000 to 100,000 births. * **Absence of Femur (PFFD):** Proximal Femoral Focal Deficiency is a rare developmental defect (1 in 50,000 births) involving the hip and femur. * **Absence of Fibula:** Fibular hemimelia is the most common long-bone deficiency, but its overall incidence (1 in 40,000) is still significantly lower than that of clubfoot. **High-Yield Clinical Pearls for NEET-PG:** 1. **Standard Treatment:** The **Ponseti Method** (serial casting) is the gold standard. The order of correction follows the acronym **CAVE** (Cavus first, then Adduction and Varus, finally Equinus). 2. **Pirani Score:** Used to assess the severity of CTEV and monitor progress during casting. 3. **Kite’s Angle:** On X-ray (AP view), the angle between the talus and calcaneus is **decreased** in CTEV (parallelism). 4. **Relapse Prevention:** After casting, a **Steenbeek or Denis Browne splint** is used (held in 70° external rotation) until age 3–4 years.

Q: Vertical talus is associated with:

Congenital flat foot. **Explanation:** **Congenital Vertical Talus (CVT)**, also known as **"Rocker-Bottom Foot,"** is a rare form of rigid congenital flat foot. The core pathology involves a fixed dorsal dislocation of the navicular on the head of the talus. Because the talus is locked in a vertical position (plantarflexed), the midfoot is displaced dorsally, resulting in the loss of the medial longitudinal arch and a characteristic convex appearance of the sole. **Analysis of Options:** * **A. Congenital flat foot (Correct):** CVT is the most severe form of rigid flat foot present at birth. Unlike flexible flat foot, it does not resolve with age and requires surgical intervention. * **B. Ankle dislocation:** While the talonavicular joint is dislocated, the ankle joint (talocrural joint) itself remains intact. * **C. Talus fracture:** Vertical talus is a congenital structural deformity, not a traumatic injury. Fractures of the talus in children are rare and usually result from high-energy trauma (e.g., Aviator’s fracture). * **D. Pes cavus:** This is a high-arched foot, the clinical opposite of the flat foot seen in CVT. Pes cavus is often associated with neuromuscular conditions like Friedreich’s ataxia or Charcot-Marie-Tooth disease. **NEET-PG High-Yield Pearls:** 1. **Radiological Hallmark:** On a lateral X-ray in forced plantarflexion, the talus remains vertical and does not align with the first metatarsal (the **Meary’s angle** remains increased). 2. **Associations:** Up to 50% of cases are associated with neuromuscular disorders like **Myelomeningocele** or chromosomal abnormalities (Trisomy 13, 15, 18). 3. **Differential Diagnosis:** Must be distinguished from **Calcaneovalgus foot**, which is a flexible postural deformity that corrects with passive stretching. 4. **Treatment:** The "Reverse Ponseti" technique (serial casting) followed by surgical pinning is the modern management approach.

Q: What is the known etiology of Perthes disease?

Unknown. **Explanation:** **Legg-Calvé-Perthes Disease (LCPD)** is an idiopathic avascular necrosis of the femoral head occurring in children, typically between ages 4 and 8. **1. Why the correct answer is "Unknown":** Despite extensive research, the exact primary cause of Perthes disease remains **unknown (idiopathic)**. The underlying pathophysiology involves a temporary interruption of the blood supply to the capital femoral epiphysis, leading to bone infarction and subsequent remodeling. While various theories suggest associations with hypercoagulability (Protein C or S deficiency), venous obstruction, or delayed skeletal maturity, none have been definitively proven as the universal etiology. **2. Why the other options are incorrect:** * **Options A & B (Pyogenic/Tubercular Infection):** Perthes is a non-infectious, aseptic process. While Septic Arthritis (Pyogenic) or TB Hip can mimic the clinical presentation (limp and pain), they involve inflammatory markers (raised ESR/CRP) and joint destruction driven by pathogens, which are absent in Perthes. * **Option C (Trauma):** While a history of minor trauma is often reported by parents, it is generally considered an incidental finding that brings the pre-existing condition to medical attention rather than being the causative factor. **Clinical Pearls for NEET-PG:** * **Classic Presentation:** A painless (or mildly painful) limp in a young boy (Male:Female ratio = 4:1). * **Radiological Sign:** The **"Crescent Sign"** (subchondral fracture) is a pathognomonic early sign. * **Staging:** Commonly classified using the **Waldenström stages** (Initial, Fragmentation, Reossification, and Healed). * **Prognosis:** The most important prognostic factor is the **age at onset**; children younger than 6 years generally have better outcomes due to higher remodeling potential.

Q: Which classification system is NOT used for Perthes' disease?

Salter Harris Classification. **Explanation:** The correct answer is **D. Salter-Harris Classification**. This system is used to categorize **physeal (growth plate) fractures** in children based on the involvement of the epiphysis, physis, and metaphysis. It is not used for Perthes' disease, which is an idiopathic avascular necrosis of the femoral head. **Analysis of other options:** * **Catterall Classification:** Based on the extent of involvement of the femoral head seen on AP and lateral X-rays. It divides the disease into four groups (I-IV) based on the size of the necrotic segment. * **Salter-Thompson Classification:** A simplified version of Catterall’s, focusing on the extent of the **subchondral fracture (crescent sign)**. Group A involves less than half the head, while Group B involves more than half. * **Stulberg Classification:** This is used to assess the **long-term prognosis** and end-stage morphology of the hip after the disease has run its course. It classifies the femoral head shape (spherical, ovoid, or flat) and its congruency with the acetabulum. **High-Yield Clinical Pearls for NEET-PG:** * **Herring (Lateral Pillar) Classification:** Currently the most popular prognostic system. It is based on the height of the lateral pillar of the capital femoral epiphysis during the fragmentation stage. * **Age of Onset:** Typically occurs in children aged 4–8 years; more common in boys. * **Earliest Sign:** The earliest radiographic sign is often a **widening of the joint space** or a small, dense epiphysis. * **Gage’s Sign:** A V-shaped radiolucency on the lateral side of the epiphysis (a "Head-at-risk" sign).

Q: Which of the following conditions is NOT associated with a bird-face appearance?

Scleroderma. **Explanation:** The "bird-face" appearance (micrognathia and retrognathia) is characterized by a receding chin and a prominent nose, typically resulting from the failure of normal mandibular development or restricted growth at the temporomandibular joint (TMJ). **Why Scleroderma is the Correct Answer:** Scleroderma (Systemic Sclerosis) is associated with a **"Mask-like" facies** or "Mousier facies." The skin becomes tight, shiny, and loses its folds. Characteristic features include microstomia (small mouth) and radial furrowing around the lips (Maussage sign), but it does not typically produce the skeletal retrognathia seen in bird-face appearance. **Analysis of Incorrect Options:** * **Bilateral TMJ Ankylosis:** If this occurs during the growth period (childhood), the mandible fails to grow forward and downward. This leads to severe retrognathia and a classic bird-face deformity. * **Treacher Collins Syndrome:** An autosomal dominant disorder of craniofacial development (1st and 2nd branchial arches). It presents with mandibular hypoplasia, malar hypoplasia, and downward-slanting palpebral fissures, creating a bird-like profile. * **Pierre Robin Syndrome:** A triad of micrognathia, glossoptosis (tongue falling back), and cleft palate. The underdeveloped mandible is a hallmark feature, leading to the bird-face look. **High-Yield Clinical Pearls for NEET-PG:** * **Bird-face appearance:** Think of conditions causing **Mandibular Hypoplasia.** * **Stickler Syndrome:** Another high-yield association with bird-face appearance and Pierre Robin sequence. * **Hallermann-Streiff Syndrome:** Also known as "Bird-headed dwarfism." * **Scleroderma:** Look for "Raynaud’s phenomenon" and "CREST syndrome" in the history to differentiate it from primary skeletal deformities.

Q: A six-year-old child presented with a gradually progressive valgus deformity at his right elbow for the past 3 years. He has a history of cast application for 6 weeks after a fall on an outstretched hand 3 years ago. What is the probable fracture that occurred?

Malunited lateral condylar fracture of the humerus. ### Explanation The correct answer is **Malunited lateral condylar fracture of the humerus**. **1. Why it is correct:** Lateral condyle fractures are "fractures of necessity" (usually requiring ORIF) because they are intra-articular and prone to non-union due to the pull of the extensor muscles and bathing in synovial fluid. If treated conservatively with a cast (as in this case), they often result in **non-union** or malunion. This leads to a cessation of growth on the lateral side of the distal humerus while the medial side continues to grow. This asymmetrical growth results in a **progressive cubitus valgus** deformity. **2. Why the other options are incorrect:** * **Malunited supracondylar fracture:** This is the most common pediatric elbow fracture. Malunion here typically results in **Cubitus Varus** (Gunstock deformity) due to coronal tilt, not progressive valgus. * **Posterior dislocation of the elbow:** While it can cause stiffness or heterotopic ossification, it does not typically result in a progressive angular deformity over years. * **Fracture of the medial condyle:** This is rare in children. If it leads to growth arrest or malunion, it would result in a **cubitus varus** deformity. **3. Clinical Pearls for NEET-PG:** * **Tardy Ulnar Nerve Palsy:** A classic complication of long-standing cubitus valgus (secondary to lateral condyle non-union). The ulnar nerve gets stretched over the medial epicondyle. * **Milch Classification:** Used for lateral condyle fractures (Type I: through the epiphysis; Type II: through the physis—most common). * **Progressive vs. Static:** Supracondylar malunion is a **static** deformity (occurs at the time of healing), whereas lateral condyle non-union causes a **progressive** deformity (due to growth plate disturbance).

Q: Which of the following terms is synonymous with Blount's disease?

Infantile Tibia Vara. **Explanation:** **Blount’s Disease** is a developmental disorder characterized by disordered endochondral ossification of the medial aspect of the proximal tibial physis. This leads to a progressive varus deformity (bowing) of the legs. 1. **Why the correct answer is right:** The term **Infantile Tibia Vara** is synonymous with the early-onset form of Blount's disease (typically appearing between ages 2–5). It is the most common presentation of the condition. The underlying pathology involves excessive compressive forces across the medial growth plate, leading to growth suppression (Heuter-Volkmann Law) and subsequent medial tibial beaking. 2. **Why the incorrect options are wrong:** * **Genu Valgum:** This refers to "knock-knees," where the knees angle in and the ankles are apart. Blount’s disease causes Genu Varum (bow-legs). * **Genu Recurvatum:** This refers to hyperextension of the knee joint, which is not the primary deformity in Blount’s. * **Adolescent Tibia Vara:** While this is a form of Blount's disease (late-onset), it is not considered a *synonym* for the disease as a whole. "Tibia Vara" is the general clinical term, but "Infantile Tibia Vara" is the classic synonym used in textbooks to describe the primary entity. **High-Yield Clinical Pearls for NEET-PG:** * **Radiographic Hallmark:** The **Drennan’s Metaphyseal-Diaphyseal Angle (MDA)**. An angle **>16°** is highly suggestive of Blount’s rather than physiologic bowing. * **Langenskiöld Classification:** Used to stage the severity based on the degree of metaphyseal depression and epiphyseal changes (Stages I-VI). * **Risk Factors:** Early walking, obesity, and African-American ethnicity. * **Treatment:** Bracing (KAFO) is effective for Stage I-II in children <3 years; surgical osteotomy is required for advanced stages or older children.

Question 1

What is the commonest congenital deformity?

Accepted Answer

Congenital club foot

Answer

Congenital club hand

Answer

Absence of femur

Answer

Absence of fibula

Question 2

Vertical talus is associated with:

Accepted Answer

Congenital flat foot

Answer

Ankle dislocation

Answer

Talus fracture

Answer

Pes cavus

Question 3

What is the known etiology of Perthes disease?

Accepted Answer

Unknown

Answer

Pyogenic infection

Answer

Tubercular infection

Answer

Trauma

Question 4

Which classification system is NOT used for Perthes' disease?

Accepted Answer

Salter Harris Classification

Answer

Catterall classification

Answer

Salter Thompson classification

Answer

Stulberg classification

Question 5

A one-and-a-half-year-old child fell while holding her father's hand. She subsequently cried and held her forearm in a pronated position, refusing to move the affected extremity. What is the most appropriate management at this stage?

Accepted Answer

Supinate the forearm

Answer

Examine the child under general anesthesia

Answer

Elevate the limb and observe

Answer

Investigate for osteomyelitis

Question 6

Which of the following conditions is NOT associated with a bird-face appearance?

Accepted Answer

Scleroderma

Answer

Bilateral temporomandibular joint ankylosis

Answer

Treacher Collins syndrome

Answer

Pierre Robin syndrome

Question 7

A six-year-old child presented with a gradually progressive valgus deformity at his right elbow for the past 3 years. He has a history of cast application for 6 weeks after a fall on an outstretched hand 3 years ago. What is the probable fracture that occurred?

Accepted Answer

Malunited lateral condylar fracture of the humerus

Answer

Malunited supracondylar fracture of the humerus

Answer

Posterior dislocation of the elbow

Answer

Fracture of the medial condyle of the humerus

Question 8

In a newborn child, abduction and internal rotation producing a click sound is indicative of which sign?

Accepted Answer

Ortolani's sign

Answer

Telescoping sign

Answer

Lachman's sign

Answer

Mc Murray's sign

Question 9

Which of the following terms is synonymous with Blount's disease?

Accepted Answer

Infantile Tibia Vara

Answer

Genu Valgum

Answer

Genu Recurvatum

Answer

Adolescent tibia vara

Question 10

A one-year-old child presented with multiple fractures in various stages of healing. What is the most probable diagnosis in this case?

Accepted Answer

Battered baby syndrome

Answer

Scurvy

Answer

Rickets

Answer

Sickle cell disease

Pediatric Orthopaedics — MCQs

Pediatric Orthopaedics — MCQs

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