Pediatric Orthopaedics Practice Questions

Q: What is the typical position of the lower limb in a post-polio deformity of the hip?

Flexion, Abduction, External rotation. ### Explanation The characteristic deformity of the hip in **Post-Polio Residual Paralysis (PPRP)** is **Flexion, Abduction, and External Rotation (FABER)**. **1. Why Flexion, Abduction, and External Rotation is Correct:** In Polio, muscle involvement is often asymmetrical and patchy. The deformity is primarily driven by the **contracture of the Iliotibial Band (ITB)** and the **Tensor Fasciae Latae (TFL)**. * **Flexion:** The TFL and Sartorius (often spared) act as flexors. * **Abduction:** The ITB is a strong abductor; its contracture pulls the hip outward. * **External Rotation:** The short external rotators are frequently stronger than the paralyzed internal rotators. Furthermore, the patient often adopts this "frog-leg" position to stabilize the pelvis during gait or sitting, leading to fixed contractures over time. **2. Why the Other Options are Incorrect:** * **Extension & Adduction (Options A & D):** These are the opposite of the typical polio pattern. Adduction deformities are more common in Cerebral Palsy (due to spasticity) or late-stage Hip Osteoarthritis. * **Internal Rotation (Options A & B):** Internal rotation is rare in PPRP because the muscles responsible (Gluteus Medius/Minimus anterior fibers) are often weaker than the external rotators. **3. Clinical Pearls for NEET-PG:** * **Ober’s Test:** Used to clinical assess the contracture of the Iliotibial Band. * **Soutter’s Release:** A surgical procedure (muscle slide) used to correct hip flexion contractures in polio. * **The "Pelvic Obliquity":** ITB contracture at the hip can lead to a secondary scoliosis and pelvic tilt. * **Triad of PPRP Hip:** Flexion, Abduction, and External Rotation is the classic "triple deformity" frequently tested in orthopedic exams.

Q: Which of the following is the MOST common skeletal manifestation in Type-1 Neurofibromatosis?

Scoliosis. ### Explanation **Neurofibromatosis Type 1 (NF-1)**, also known as von Recklinghausen disease, is an autosomal dominant multisystem disorder caused by a mutation in the *NF1* gene on chromosome 17. While it is primarily a neurocutaneous syndrome, skeletal manifestations occur in approximately 50% of patients. **Why Scoliosis is the Correct Answer:** Scoliosis is the **most common** skeletal abnormality in NF-1, affecting 10–30% of patients. It typically presents in two forms: 1. **Dystrophic (Short-segment):** Characterized by sharp angulation involving 4–6 vertebrae, often associated with vertebral body scalloping, rib penciling, and a high risk of rapid progression. 2. **Non-dystrophic:** Resembles adolescent idiopathic scoliosis and is more common but less severe. **Analysis of Incorrect Options:** * **A. Cortical thinning of long bones:** While cortical thinning and bowing (especially of the tibia) occur, they are less frequent than spinal deformities. * **B. Pseudoarthrosis:** Congenital pseudoarthrosis of the tibia is a classic "pathognomonic" sign of NF-1, but it is rare, occurring in only about 5% of cases. * **C. Sphenoid dysplasia:** This is a characteristic craniofacial feature of NF-1 (often leading to pulsating exophthalmos), but it is significantly less common than scoliosis. **High-Yield Clinical Pearls for NEET-PG:** * **Chromosome:** 17 (NF-1), 22 (NF-2). * **Pathognomonic Orthopaedic Sign:** Congenital pseudoarthrosis of the tibia (CPT). * **Radiological Sign:** "Dumbbell-shaped" tumors (neurofibromas) exiting the intervertebral foramina. * **Dystrophic Scoliosis Criteria:** Look for "penciling of ribs" and "vertebral scalloping" on X-rays. These cases often require early surgical intervention (posterior or combined fusion).

Q: Which muscle is involved in congenital muscular torticollis?

Sternocleidomastoid. ### Explanation **Correct Answer: B. Sternocleidomastoid** **Medical Concept:** Congenital Muscular Torticollis (CMT), also known as "Wry Neck," is a common pediatric condition caused by the shortening or fibrosis of the **Sternocleidomastoid (SCM)** muscle. Pathologically, there is an replacement of muscle fibers with fibrous tissue, often presenting as a firm, non-tender mass (pseudotumor) within the muscle belly shortly after birth. This leads to a characteristic deformity where the infant’s head is **tilted toward the affected side** and the **chin is rotated toward the opposite shoulder**. **Analysis of Incorrect Options:** * **A. Deltoid:** This muscle is involved in shoulder abduction and is frequently associated with Axillary nerve injuries or intramuscular injection fibrosis, but it plays no role in neck positioning. * **C. Digastric & D. Mylohyoid:** These are suprahyoid muscles involved in swallowing and depressing the mandible. They are not involved in the rotational or lateral flexion movements of the neck seen in torticollis. **Clinical Pearls for NEET-PG:** * **Associated Conditions:** Always screen for **Developmental Dysplasia of the Hip (DDH)**, as there is a 10–20% clinical association between CMT and DDH. * **Clinical Presentation:** "Cock-robin" appearance (Head tilt to the same side, chin rotation to the opposite side). * **Complications:** If left untreated, it can lead to **Plagiocephaly** (flattening of the skull) and facial asymmetry. * **Treatment:** Initial management is conservative (stretching exercises). Surgical intervention (SCM release) is indicated if the condition persists beyond 1 year of age.

Q: Which of the following statements is false regarding the Salter-Harris classification of physeal injuries?

Type V represents an injury to the perichondrial ring.. The **Salter-Harris classification** is a fundamental system used to describe fractures involving the growth plate (physis) in children. ### **Explanation of the Correct Answer** **Option D is false** because **Type V** injuries represent a **crush or compression injury** to the physis, not the perichondrial ring. In Type V, the germinal cells of the growth plate are crushed, which often leads to premature physeal closure and significant growth arrest. Injuries specifically involving the perichondrial ring are categorized under the **Rang’s classification** (as Type VI). ### **Analysis of Other Options** * **Option A:** True. The classification is specifically designed to categorize injuries based on the involvement of the **physis** relative to the metaphysis and epiphysis. * **Option B:** True. **Type II** (fracture through the physis and metaphysis) is the **most common** variety, accounting for approximately 75% of all physeal fractures. * **Option C:** True. **Type IV** is a vertical fracture that crosses the **metaphysis, physis, and epiphysis**. Because it crosses the germinal layer and involves the articular surface, it carries a high risk of growth disturbance and requires anatomical reduction. ### **NEET-PG High-Yield Pearls** * **Mnemonic (SALTER):** * **S** (Type I): **S**eparated (Straight across physis) * **A** (Type II): **A**bove (Metaphysis) - *Most common* * **L** (Type III): **L**ower (Epiphysis) * **T** (Type IV): **T**hrough/Two (Metaphysis + Epiphysis) * **ER** (Type V): **ER**asure/Crush (Compression) * **Thurston-Holland Sign:** The triangular metaphyseal fragment seen in **Type II** fractures. * **Prognosis:** Types I and II generally have a good prognosis; Types III and IV require anatomical reduction to prevent joint incongruity; Type V has the worst prognosis due to growth arrest.

Q: A 7-year-old boy has a fracture of the lateral condyle of the femur. He developed malunion because the fracture was not reduced anatomically. What would malunion of the lateral condyle of the femur produce?

Genu valgum. **Explanation:** The lateral condyle of the femur forms the lateral half of the distal femoral articular surface. In a growing child, the distal femoral epiphysis is responsible for significant longitudinal growth. **Why Genu Valgum is Correct:** When a fracture of the lateral condyle undergoes malunion (specifically if it is displaced or results in premature physeal closure/overgrowth), it alters the mechanical alignment of the knee. If the lateral condyle is displaced superiorly or fails to grow at the same rate as the medial side, the lateral support of the joint is compromised. This leads to an outward deviation of the tibia relative to the femur, resulting in a **"knock-knee"** deformity, known as **Genu Valgum**. **Analysis of Incorrect Options:** * **Genu Varum (B):** This "bow-legged" deformity occurs when there is a medial compartment collapse or malunion of the **medial condyle**. * **Genu Recurvatum (C):** This refers to hyperextension of the knee. It typically occurs due to malunion of the proximal tibia or an anterior physeal arrest of the distal femur/proximal tibia, rather than a single condylar injury. * **Dislocation of the knee (D):** While malunion causes joint incongruity and secondary osteoarthritis, it does not typically cause acute or chronic dislocation, which requires high-energy ligamentous disruption. **NEET-PG Clinical Pearls:** * **Lateral Condyle of Humerus:** The most common site for non-union in children (leads to Cubitus Valgus and Tardy Ulnar Nerve Palsy). * **Lateral Condyle of Femur:** Malunion here leads to Genu Valgum. * **Milch Classification:** Used for condylar fractures; anatomical reduction is mandatory to prevent growth arrest and angular deformities. * **Growth Contribution:** The distal femoral epiphysis contributes approximately 70% of the femur's length and 40% of the overall limb length.

Q: Which of the following statements about Caffey's disease is FALSE?

Caused by Salmonella. **Caffey’s Disease**, also known as **Infantile Cortical Hyperostosis**, is a self-limiting inflammatory disorder of infants characterized by the triad of irritability, soft tissue swelling, and bone lesions. ### Explanation of Options: * **Why D is the Correct Answer (False Statement):** Caffey’s disease is **not an infection**. Its exact etiology is unknown, though it is often associated with a mutation in the **COL1A1 gene**. It is never caused by *Salmonella* or any other pathogen. *Salmonella* is, however, the most common cause of osteomyelitis in patients with Sickle Cell Anemia—a common distractor in NEET-PG questions. * **Option A (True):** The disease typically presents in early infancy, almost always **before 6 months of age**. * **Option B (True):** The **mandible (jaw)** is the most commonly involved bone (75-80% of cases), followed by the clavicle and long bones. While it mimics the appearance of osteomyelitis clinically (fever, swelling), it is a non-infectious process. * **Option C (True):** The hallmark radiographic feature is **subperiosteal new bone formation** (cortical hyperostosis), which gives the bone a thickened appearance. ### High-Yield Clinical Pearls for NEET-PG: * **Triad:** Irritability, fever/swelling, and cortical thickening. * **Laboratory Findings:** Elevated ESR, CRP, and Alkaline Phosphatase (mimics infection/inflammation). * **Most Common Site:** Mandible (Mandibular involvement helps differentiate it from Child Abuse/Non-Accidental Injury). * **Treatment:** Usually self-limiting; resolves spontaneously within months. NSAIDs (like Naproxen or Aspirin) or steroids are used for symptomatic relief. * **Differential Diagnosis:** Osteomyelitis, Hypervitaminosis A, Scurvy, and Ewing’s Sarcoma.

Q: What is the management of posteromedial bowing of the tibia in a 6-month-old boy?

Observation. **Explanation:** **Posteromedial bowing of the tibia** is a congenital condition characterized by a calcaneovalgus foot deformity and a posterior-medial angulation of the tibia. 1. **Why Observation is Correct:** The natural history of posteromedial bowing is **spontaneous resolution** of the angular deformity. Most of the bowing corrects itself within the first 2–4 years of life through remodeling. In a 6-month-old infant, the primary management is observation and passive stretching exercises for the associated calcaneovalgus foot. No aggressive intervention is required for the bow itself at this age. 2. **Why Other Options are Incorrect:** * **Osteotomy (A):** Surgical correction via osteotomy is contraindicated in infancy because the bone remodels naturally. It is only considered in late childhood if there is a significant residual angular deformity (rare). * **Cast with Ponseti method (B):** The Ponseti method is the gold standard for *Congenital Talipes Equinovarus (CTEV)*, which involves **adduction and inversion**. Posteromedial bowing presents with the opposite (calcaneovalgus) deformity, which usually resolves with simple stretching. * **ORIF (C):** There is no fracture or instability requiring internal fixation. Posteromedial bowing is a developmental remodeling issue, not a traumatic one. 3. **Clinical Pearls for NEET-PG:** * **The "Rule of Two":** Posteromedial bowing is associated with **Leg Length Discrepancy (LLD)**. While the bow corrects, the affected limb is often 3–4 cm shorter at skeletal maturity. This LLD is the most common reason for future surgery (e.g., epiphysiodesis). * **Anterolateral Bowing:** Unlike posteromedial bowing, **anterolateral bowing** is highly pathological and is a precursor to **Congenital Pseudarthrosis of the Tibia (CPT)**, often associated with Neurofibromatosis Type 1. * **Anteromedial Bowing:** Associated with **fibular hemimelia**.

Q: A 2-year-old male child has been limping since he started walking. Examination reveals a short right lower limb with limited abduction at the hip. The Trendelenburg sign is positive, however, telescoping is absent. What is the most probable diagnosis?

Congenital coxa vara. **Explanation:** The clinical presentation of a 2-year-old with a painless limp, limb shortening, and limited abduction points toward a proximal femoral deformity. **Why Congenital Coxa Vara is correct:** Congenital (Developmental) Coxa Vara is characterized by a decreased neck-shaft angle (less than 120°). 1. **Limp & Trendelenburg Sign:** The decreased angle brings the greater trochanter closer to the ilium, causing **abductor insufficiency** (shortened moment arm of the gluteus medius), leading to a positive Trendelenburg sign and a lurching gait. 2. **Limited Abduction:** The high position of the greater trochanter causes mechanical impingement against the ilium during abduction. 3. **Absence of Telescoping:** This is the **crucial differentiator**. In Coxa Vara, the femoral head is stable within the acetabulum, so telescoping is absent. **Why incorrect options are wrong:** * **Congenital Dislocation of the Hip (DDH):** While it presents with shortening and limited abduction, **telescoping would be positive** because the femoral head is not contained in the socket. * **Perthes' Disease:** This typically affects older children (4–8 years). While it causes limited abduction, it is an avascular necrosis and usually presents with pain and a more acute onset than a limp present since the first steps. * **Kienböck's Deformity:** This refers to avascular necrosis of the **lunate bone** in the wrist, unrelated to hip pathology. **High-Yield Clinical Pearls for NEET-PG:** * **Radiographic Hallmark:** A decreased neck-shaft angle and the presence of a **Fairbank’s triangle** (an inverted V-shaped secondary ossification center in the lower part of the femoral neck). * **Hilgenreiner’s Epiphyseal Angle (HEA):** Used to assess progression; an angle **>60°** usually requires surgical correction (Valgus Osteotomy). * **Telescoping Sign:** Positive in DDH and pathological fractures; negative in Coxa Vara and Perthes.

Q: Fraying at the ends of long bones is seen in which of the following conditions?

Rickets. **Explanation:** **Rickets** is characterized by a failure of mineralization of the osteoid matrix at the growth plate. In a growing child, this leads to an accumulation of uncalcified cartilage and disorganized osteoid. Radiologically, this manifests as **fraying** (shaggy, irregular margins of the metaphysis), **cupping** (concave deformity of the metaphysis), and **splaying** (widening of the ends of long bones). These changes are most prominent at sites of rapid growth, such as the distal radius, ulna, and around the knee. **Why other options are incorrect:** * **Scurvy:** Characterized by a defect in collagen synthesis. Classic radiological signs include the **White line of Frankel** (dense zone of provisional calcification), **Wimberger’s ring** (sclerotic rim around epiphysis), and **Pelkan spurs**, but not fraying. * **Osteogenesis Imperfecta:** A genetic disorder of Type 1 collagen. It presents with generalized osteopenia, multiple fractures, "popcorn" epiphyses, and cortical thinning, rather than metaphyseal fraying. * **Congenital Syphilis:** Typically shows **Wimberger’s sign** (erosion of the medial aspect of the proximal tibial metaphysis) and periostitis. While it involves the metaphysis, the specific "frayed" appearance is pathognomonic for Rickets. **High-Yield Clinical Pearls for NEET-PG:** * **Earliest radiological sign of Rickets:** Fraying and cupping of the distal ends of the radius and ulna. * **Earliest clinical sign of Rickets:** Craniotabes (softening of skull bones). * **Harrison’s Sulcus:** A horizontal groove along the lower border of the thorax corresponding to the insertion of the diaphragm, seen in Rickets. * **Rachitic Rosary:** Palpable/visible enlargement of the costochondral junctions.

Question 1

What is the typical position of the lower limb in a post-polio deformity of the hip?

Accepted Answer

Flexion, Abduction, External rotation

Answer

Extension, Adduction, Internal rotation

Answer

Extension, Abduction, Internal rotation

Answer

Flexion, Adduction, External rotation

Question 2

Which of the following is the MOST common skeletal manifestation in Type-1 Neurofibromatosis?

Accepted Answer

Scoliosis

Answer

Cortical thinning of long bones

Answer

Pseudoarthrosis

Answer

Sphenoid dysplasia

Question 3

Which muscle is involved in congenital muscular torticollis?

Accepted Answer

Sternocleidomastoid

Answer

Deltoid

Answer

Digastric

Answer

Mylohyoid

Question 4

Which of the following statements is false regarding the Salter-Harris classification of physeal injuries?

Accepted Answer

Type V represents an injury to the perichondrial ring.

Answer

It classifies injuries involving the physis (growth plate).

Answer

Type II is the most common type of physeal injury.

Answer

Type IV involves a fracture line passing through the epiphysis, physis, and metaphysis.

Question 5

Excision of the head of the radius in a child should not be done because:

Accepted Answer

It causes subluxation of the inferior radio-ulnar joint.

Answer

It produces instability of the elbow joint.

Answer

It leads to secondary osteoarthritis of the elbow.

Answer

It causes myositis ossificans.

Question 6

A 7-year-old boy has a fracture of the lateral condyle of the femur. He developed malunion because the fracture was not reduced anatomically. What would malunion of the lateral condyle of the femur produce?

Accepted Answer

Genu valgum

Answer

Genu varum

Answer

Genu recurvatum

Answer

Dislocation of the knee

Question 7

Which of the following statements about Caffey's disease is FALSE?

Accepted Answer

Caused by Salmonella

Answer

Usually occurs in infants < 6 months

Answer

Jaw Osteomyelitis

Answer

Cortical hyperostosis

Question 8

What is the management of posteromedial bowing of the tibia in a 6-month-old boy?

Accepted Answer

Observation

Answer

Osteotomy

Answer

Cast with Ponseti method

Answer

ORIF (Open Reduction Internal Fixation)

Question 9

A 2-year-old male child has been limping since he started walking. Examination reveals a short right lower limb with limited abduction at the hip. The Trendelenburg sign is positive, however, telescoping is absent. What is the most probable diagnosis?

Accepted Answer

Congenital coxa vara

Answer

Kienböck's deformity

Answer

Congenital dislocation of the hip

Answer

Perthes' disease

Question 10

Fraying at the ends of long bones is seen in which of the following conditions?

Accepted Answer

Rickets

Answer

Scurvy

Answer

Osteogenesis imperfecta

Answer

Congenital syphilis

Pediatric Orthopaedics — MCQs

Pediatric Orthopaedics — MCQs

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