Pediatric Orthopaedics Practice Questions

Q: A 4-year-old child complains of a painful limb. What is the most likely cause?

Perthe's disease. ***Perthe's disease*** - **Avascular necrosis** of the femoral head typically presents in children aged **4-8 years** with painful limping, matching this case perfectly. - The hallmark presentation is a **painful limp** with hip pain that may radiate to the knee, often worse with activity. *Poliomyelitis* - This is a **viral infection** affecting the anterior horn cells of the spinal cord, causing **flaccid paralysis** rather than limb pain. - The condition is now extremely rare due to **vaccination programs** and would present with weakness, not isolated pain. *Infantile coxa vara* - This is a **developmental deformity** of the hip that typically presents in **infancy to early childhood** (under 3 years). - The condition is usually **painless** and presents with limping due to limb length discrepancy, not pain. *Congenital talipes equinovarus (CTEV)* - This is a **congenital foot deformity** present at birth, characterized by inward and downward turning of the foot. - The condition affects the **foot and ankle**, not causing limb pain, and would be evident from birth rather than presenting at age 4.

Q: What is the most commonly accepted etiology for Perthes disease?

Trauma. ### Explanation **Legg-Calvé-Perthes Disease (LCPD)** is an idiopathic avascular necrosis (AVN) of the proximal femoral epiphysis in children. While the exact primary trigger remains a subject of debate, **Trauma** is the most commonly accepted etiology in the context of competitive exams like NEET-PG. **Why Trauma is the Correct Answer:** The underlying pathophysiology of Perthes disease involves an interruption of the blood supply to the femoral head. Recurrent **micro-trauma** or a single traumatic event is believed to increase intra-articular pressure or directly damage the fragile subsynovial vessels (the primary blood supply to the developing femoral head). This mechanical disruption leads to ischemia, bone infarction, and subsequent collapse. **Why Other Options are Incorrect:** * **Pyogenic & Tubercular Infection (A & B):** These cause Septic Arthritis or Osteomyelitis. While infection can lead to joint destruction, Perthes is strictly a non-infectious, aseptic process. * **Unknown (D):** Although often termed "idiopathic," the mechanical/vascular theory triggered by trauma is the most widely accepted academic explanation for the initiation of the ischemic process. **High-Yield Clinical Pearls for NEET-PG:** * **Demographics:** Most common in boys (4:1 ratio) aged 4–8 years. * **Clinical Feature:** Painless limp or hip/knee pain with restricted **abduction and internal rotation**. * **Radiological Sign:** **Crescent Sign** (subchondral fracture) is an early finding; "Mushroom-shaped head" is a late finding. * **Classification:** Catterall (extent of involvement) and Herring (Lateral Pillar height) are used for prognosis. * **Management:** The goal is "Containment" of the femoral head within the acetabulum.

Q: All of the following are seen in Rickets except –

Gunstock deformity. **Explanation:** The correct answer is **Gunstock deformity** (Cubitus varus). This deformity is a classic late complication of a **Supracondylar fracture of the humerus** in children, usually resulting from malunion. It is not a feature of Rickets. **Why the other options are seen in Rickets:** * **Bow legs (Genu varum):** Rickets causes defective mineralization of the osteoid matrix, leading to "soft" bones. When a child starts weight-bearing, the softened long bones of the lower limbs bend under gravity, resulting in bow legs. * **Pot belly:** This occurs due to generalized muscular hypotonia (low muscle tone) and weakness of the abdominal wall muscles, which is a systemic manifestation of Vitamin D deficiency. * **Craniotabes:** This is often the earliest clinical sign of Rickets (seen in infants <6 months). it refers to the softening of the skull bones (occipital and parietal), which give a "ping-pong ball" sensation upon pressure. **High-Yield Clinical Pearls for NEET-PG:** * **Radiological Signs of Rickets:** Cupping, fraying, and splaying of the metaphysis (best seen at the distal radius and ulna). * **Rachitic Rosary:** Palpable enlargement of the costochondral junctions (rounded beads). In contrast, **Scorbutic rosary** (Scurvy) is sharp/angular due to subluxation of the sternum. * **Harrison’s Sulcus:** A horizontal groove along the lower margin of the thorax at the insertion of the diaphragm. * **Biochemical profile:** Low/Normal Calcium, Low Phosphate, and **Elevated Alkaline Phosphatase (ALP)**—ALP is the most sensitive marker for disease activity.

Q: Posterior iliac horns are seen in which of the following conditions?

Nail patella syndrome. **Explanation:** **Nail-Patella Syndrome (NPS)**, also known as **Fong’s Disease** or Hereditary Osteo-onychodysplasia (HOOD), is an autosomal dominant disorder caused by a mutation in the **LMX1B gene**. The presence of **posterior iliac horns** is considered a **pathognomonic** radiological feature of this condition, occurring in approximately 80% of cases. These are bilateral, symmetrical bony outgrowths arising from the posterior aspect of the iliac bones. **Why the other options are incorrect:** * **Fisher’s Syndrome:** A variant of Guillain-Barré syndrome characterized by the triad of ataxia, areflexia, and ophthalmoplegia. It is a neurological condition with no specific orthopedic bony outgrowths. * **Crouzon Syndrome:** A branchial arch syndrome involving craniosynostosis (premature fusion of skull bones), resulting in midface hypoplasia and proptosis, but not iliac abnormalities. * **Pierre Robin Sequence:** Characterized by the triad of micrognathia, glossoptosis, and cleft palate. It affects the craniofacial structures rather than the pelvic girdle. **High-Yield Clinical Pearls for NEET-PG:** * **Tetrad of NPS:** 1. **Nails:** Hypoplastic or absent (especially the thumb). 2. **Patella:** Hypoplastic or absent (leads to recurrent dislocations). 3. **Elbows:** Limited extension/supination due to radial head hypoplasia. 4. **Iliac Horns:** Pathognomonic radiological sign. * **Systemic Involvement:** Up to 40% of patients develop **nephropathy** (resembling glomerulonephritis), which is the most serious complication and can lead to renal failure. * **Lester’s Sign:** Hyperpigmentation of the pupillary margin of the iris (seen in some NPS patients).

Q: Which of the following characteristics are TRUE or FALSE about osteopetrosis in a child? 1. Growth retardation 2. Mental retardation 3. Multiple fractures 4. Cataract 5. Hepatosplenomegaly

1, 3, 5 True & 2, 4 False. **Explanation:** **Osteopetrosis** (Albers-Schönberg disease or Marble Bone Disease) is a rare genetic disorder characterized by **defective osteoclast function**. This leads to a failure of bone resorption, resulting in excessively dense but brittle bones. **Why Option A is correct:** 1. **Growth Retardation (True):** Defective remodeling of the primary spongiosa into lamellar bone interferes with longitudinal growth, leading to short stature. 2. **Mental Retardation (False):** Intelligence is typically **normal** in osteopetrosis. Neurological deficits are usually mechanical (e.g., cranial nerve compression due to bony overgrowth of foramina), not cognitive. 3. **Multiple Fractures (True):** Despite increased bone density on X-ray ("chalky bones"), the lack of a proper trabecular pattern makes the bones extremely brittle and prone to pathological fractures. 4. **Cataract (False):** Cataracts are not a feature of this disease. However, **optic atrophy** and blindness are common due to compression of the optic nerve in the optic canal. 5. **Hepatosplenomegaly (True):** As the marrow cavity is obliterated by dense bone, the body resorts to **extramedullary hematopoiesis** in the liver and spleen to compensate for life-threatening anemia and thrombocytopenia. **High-Yield NEET-PG Pearls:** * **Radiological Signs:** "Bone-within-a-bone" appearance, "Sandwich vertebrae" (Rugger-Jersey spine), and "Erlenmeyer flask deformity" of the distal femur. * **Complications:** Pancytopenia (leading to infections and bleeding), cranial nerve palsies (II, VII, and VIII), and osteomyelitis (especially of the mandible). * **Treatment:** Bone marrow transplant is the mainstay for the infantile (malignant) form to provide functional osteoclasts.

Q: Which of the following is not a component of Kocher's criteria when diagnosing septic arthritis of the hip?

C-reactive protein (CRP) > 20 mg/L.. **Explanation:** Kocher’s criteria is a high-yield clinical prediction tool used to differentiate **Septic Arthritis** from Transient Synovitis in a child with a painful hip. The diagnosis is critical because septic arthritis is a surgical emergency. **Why Option D is the correct answer:** While C-reactive protein (CRP) is a highly sensitive marker for inflammation and is often used in clinical practice to monitor treatment response, it was **not** part of the original four criteria described by Kocher et al. Later studies (Cady et al.) suggested adding CRP >20 mg/L as a fifth independent predictor, but it remains excluded from the classic "Kocher’s Criteria." **Analysis of Incorrect Options (The 4 Original Criteria):** 1. **Non-weight-bearing (Option A):** Inability to bear weight on the affected side is a primary clinical indicator. 2. **ESR > 40 mm/hr (Option B):** An elevated Erythrocyte Sedimentation Rate indicates systemic inflammation. 3. **WBC Count > 12,000/mm³ (Option C):** Peripheral leukocytosis is the third laboratory component. 4. **Fever > 38.5°C (101.3°F):** (Not listed in options but is the 4th criterion). **Clinical Pearls for NEET-PG:** * **Probability of Septic Arthritis:** * 1/4 criteria: 3% * 2/4 criteria: 40% * 3/4 criteria: 93% * 4/4 criteria: **99%** * **Gold Standard Diagnosis:** Joint aspiration (Arthrocentesis) showing a synovial WBC count >50,000/mm³ (predominantly neutrophils). * **Most Common Organism:** *Staphylococcus aureus*. * **Management:** Emergency incision and drainage (Arthrotomy) + intravenous antibiotics.

Q: What is the most common complication of a lateral condylar fracture in children?

Valgus deformity. **Explanation:** Lateral condylar fractures are the second most common elbow fractures in children (after supracondylar fractures). They are **Salter-Harris Type IV** injuries, meaning they involve the joint surface and the growth plate. **Why Valgus Deformity is Correct:** The lateral condyle includes the growth center for the lateral part of the distal humerus. A fracture here often leads to **lateral physeal arrest** (premature closure of the growth plate) or a **non-union**. While the lateral side stops growing, the medial side (trochlea) continues to grow normally. This asymmetrical growth results in an increasing outward angulation of the forearm, known as **Cubitus Valgus**. **Analysis of Incorrect Options:** * **Cubitus Varus (B):** This is the most common complication of **Supracondylar fractures** of the humerus (due to malunion), not lateral condyle fractures. * **Malunion (C):** While malunion can occur, **Non-union** is actually a more notorious and frequent complication of lateral condyle fractures due to the bathing of the fracture line in synovial fluid and the pull of the extensor muscles. * **Hyperextension (D):** This is not a typical complication of this fracture; it is more commonly associated with ligamentous laxity or malaligned supracondylar fractures. **High-Yield Clinical Pearls for NEET-PG:** * **Tardy Ulnar Nerve Palsy:** This is a classic late complication of lateral condyle fractures. The progressive **Cubitus Valgus** stretches the ulnar nerve as it rounds the medial epicondyle, leading to delayed paralysis (often years later). * **Milch Classification:** Used to categorize these fractures based on whether the fracture line passes lateral (Type I) or medial (Type II) to the trochlear groove. * **Management:** Because they are intra-articular, even minimally displaced fractures (>2mm) require **Open Reduction and Internal Fixation (ORIF)** to prevent non-union and subsequent deformity.

Q: French osteotomy is used in the treatment of which condition?

Cubitus varus. **Explanation:** **French osteotomy** is a specific surgical procedure used to correct **Cubitus varus** deformity, commonly known as "Gunstock deformity." This deformity most frequently occurs as a late complication of a malunited supracondylar fracture of the humerus in children. 1. **Why Cubitus Varus is Correct:** The French osteotomy is a **lateral closing wedge osteotomy** of the distal humerus. It involves removing a wedge of bone from the lateral side and fixing it with two screws and a tension-band wire (or a small plate). This procedure corrects the triplanar deformity (primarily the varus angulation and internal rotation) to restore the normal carrying angle of the elbow. 2. **Why Other Options are Incorrect:** * **Cubitus valgus:** While osteotomies can treat this (often caused by lateral condyle non-union), the French technique is specifically described for varus correction. * **Coxa vara:** This is a hip deformity (decreased neck-shaft angle). It is treated with proximal femoral osteotomies, such as the **Pauwel’s osteotomy** or **Borden’s osteotomy**, not the French osteotomy. * **Coxa valga:** This is an increased neck-shaft angle of the femur, usually managed with a **Varus Derotation Osteotomy (VDRO)**. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of Cubitus varus:** Malunited supracondylar fracture (due to inadequate reduction of the medial tilt/rotation). * **Deformity components:** It is a triplanar deformity (Varus + Internal rotation + Hyperextension). * **Indication for surgery:** Primarily cosmetic; it rarely affects elbow function or range of motion. * **Other osteotomies for Cubitus varus:** King’s osteotomy, Amspacher and Fowler osteotomy.

Q: Which of the following statements is FALSE regarding radial club hand?

Hand is deviated to the ulnar side.. ***Hand is deviated to the ulnar side*** - This statement is **FALSE** - in radial club hand, the hand deviates toward the **radial side** (thumb side), not the ulnar side. - The deviation occurs due to **absent or hypoplastic radius**, causing the hand to bend toward the deficient radial side. *Caused by deficiency of the radius and thumb* - This statement is **TRUE** - radial club hand results from **congenital absence or hypoplasia** of the radius bone. - Often associated with **thumb aplasia or hypoplasia**, as the thumb development is closely linked to radial formation. *Associated conditions include Holt-Oram syndrome and VACTERL association* - This statement is **TRUE** - radial club hand is frequently seen with **Holt-Oram syndrome** (cardiac and upper limb defects). - Also associated with **VACTERL association**, **TAR syndrome**, and **Fanconi anemia**. *Preferred management includes pollicization and centralization of the ulna* - This statement is **TRUE** - **centralization** involves positioning the carpus over the distal ulna for better alignment. - **Pollicization** converts the index finger into a functional thumb when the thumb is absent or severely hypoplastic.

Question 1

A 4-year-old child complains of a painful limb. What is the most likely cause?

Accepted Answer

Perthe's disease

Answer

Poliomyelitis

Answer

Infantile coxa vara

Answer

Congenital talipes equinovarus (CTEV)

Question 2

What is the most commonly accepted etiology for Perthes disease?

Accepted Answer

Trauma

Answer

Pyogenic infection

Answer

Tubercular infection

Answer

Unknown

Question 3

All of the following are seen in Rickets except –

Accepted Answer

Gunstock deformity

Answer

Bow legs

Answer

Pot belly

Answer

Craniotabes

Question 4

Posterior iliac horns are seen in which of the following conditions?

Accepted Answer

Nail patella syndrome

Answer

Fisher's syndrome

Answer

Crouzan syndrome

Answer

Pierre Robbins syndrome

Question 5

Which of the following characteristics are TRUE or FALSE about osteopetrosis in a child? 1. Growth retardation 2. Mental retardation 3. Multiple fractures 4. Cataract 5. Hepatosplenomegaly

Accepted Answer

1, 3, 5 True & 2, 4 False

Answer

1, 3, 4 True & 2, 5 False

Answer

1, 3, 4 True & 5, 2 False

Answer

2, 3 False & 1, 4, 5 True

Question 6

All of the following are true about a pulled elbow except?

Accepted Answer

The elbow is fully flexed

Answer

The forearm lies in pronation

Answer

It is treated by fully supinating the forearm

Answer

It is a dislocation of the radial head

Question 7

Which of the following is not a component of Kocher's criteria when diagnosing septic arthritis of the hip?

Accepted Answer

C-reactive protein (CRP) > 20 mg/L.

Answer

Non-weight-bearing on the affected side.

Answer

Erythrocyte sedimentation rate (ESR) greater than 40mm/hr.

Answer

White blood cell (WBC) count of >12000/mm³.

Question 8

What is the most common complication of a lateral condylar fracture in children?

Accepted Answer

Valgus deformity

Answer

Cubitus varus

Answer

Malunion

Answer

Hyperextension

Question 9

French osteotomy is used in the treatment of which condition?

Accepted Answer

Cubitus varus

Answer

Cubitus valgus

Answer

Coxa vara

Answer

Coxa valga

Question 10

Which of the following statements is FALSE regarding radial club hand?

Accepted Answer

Hand is deviated to the ulnar side.

Answer

Caused by deficiency of the radius and thumb.

Answer

Associated conditions include Holt-Oram syndrome and VACTERL association.

Answer

Preferred management includes pollicization and centralization of the ulna.

Pediatric Orthopaedics — MCQs

Pediatric Orthopaedics — MCQs

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