Pediatric Orthopaedics Practice Questions

Q: A 6-year-old child presents with a limp and limited hip abduction. An X-ray reveals flattening of the femoral head. What is the most likely diagnosis?

Legg-Calvé-Perthes disease. ***Legg-Calvé-Perthes disease*** - Characterized by **avascular necrosis** of the femoral head, leading to **flattening** seen on X-ray and symptoms such as a limp and limited hip abduction. - Typically presents in children ages **4-8**, aligning with this child's age and symptoms. *Slipped capital femoral epiphysis* - Generally occurs in **older children** and adolescents, usually presenting with **hip pain** and not primarily limp or abduction issues. - X-ray findings typically show **displacement of the femoral head**, rather than **flattening**. *Developmental dysplasia of the hip* - This condition usually presents at **birth or early infancy**, characterized by a palpable **clunk** on physical examination rather than isolated limp in a 6-year-old. - X-ray would likely show **joint dislocation** or **shallow acetabulum**, not a **flattened femoral head**. *Osteomyelitis* - More commonly presenting with **fever** and localized pain, accompanied by **systemic signs of infection**, which are absent here. - X-ray typically shows **bone infection** signs, not exclusively **joint deformity** like flattening of the femoral head.

Q: What is the most common cause of scoliosis in pediatric patients?

Idiopathic scoliosis. ***Idiopathic scoliosis*** - This is the most common form of scoliosis, making up about 80% of all cases, particularly in pediatric and adolescent populations, with no identifiable cause. - It often progresses during periods of rapid growth, especially during adolescence. *Congenital spinal deformities* - These are present at birth due to **vertebral malformations** but account for a smaller percentage of scoliosis cases compared to idiopathic forms. - The severity and progression of congenital scoliosis are often linked to the specific type of vertebral anomaly. *Neuromuscular conditions* - Conditions such as **cerebral palsy**, **muscular dystrophy**, or **spinal muscular atrophy** can cause scoliosis due to muscle weakness or imbalance. - While significant in affected individuals, the overall prevalence of neuromuscular scoliosis is lower than that of idiopathic scoliosis in the general pediatric population. *Trauma* - **Spinal trauma** can lead to scoliosis, but this is a relatively rare cause, typically resulting from fractures or injuries to the vertebral growth plates. - The onset is usually acute and directly attributable to a specific injury, unlike the gradual progression often seen in idiopathic cases.

Q: A 4-year-old child presents with fever and a mass in the thigh. An X-ray shows periosteal reaction and bone destruction. What is the next best step in diagnosis?

Bone biopsy. ***Bone biopsy*** - The combination of **fever**, a **mass**, and **X-ray findings of periosteal reaction and bone destruction** in a child is highly suspicious for **osteosarcoma** or an infectious process like **osteomyelitis**. - A **bone biopsy** is the definitive diagnostic step to differentiate between these conditions, allowing for histological examination and culture if indicated. *Bone scan* - A bone scan would show increased metabolic activity in the affected area, indicating bone pathology, but it is **not specific enough** to determine the exact nature (benign, malignant, or infectious) of the lesion. - It could help identify other areas of involvement but wouldn't provide a definitive diagnosis for the primary lesion. *Blood culture* - While **fever** could suggest an infectious process like osteomyelitis, a **blood culture** alone is often negative in bone infections, and it **cannot address the possibility of a malignant tumor**. - It would be part of the workup for infection but not the next best step for definitive diagnosis given the presence of a mass and destructive bone changes. *CT Scan* - A **CT scan** would provide more detailed anatomical information about the bone lesion, including its extent and involvement of surrounding tissues. - However, it is an **imaging modality** and cannot provide a definitive histological diagnosis, which is crucial for distinguishing between tumor and infection.

Q: Which bone cyst is most commonly associated with the proximal humerus in children?

Unicameral bone cyst. ***Unicameral bone cyst*** - **Unicameral bone cysts (UBCs)** are benign, fluid-filled lesions most commonly found in the **metaphysis of long bones** in children, particularly the **proximal humerus** and femur. - They are often asymptomatic until a pathological fracture occurs, which is a common presentation. *Aneurysmal bone cyst* - While an **aneurysmal bone cyst (ABC)** can occur in the humerus, it is less common than a UBC in the proximal humerus in children. - ABCs are typically expansile, blood-filled lesions that can arise in any bone, often presenting with pain and swelling. *Osteoid osteoma* - An **osteoid osteoma** is a benign bone tumor characterized by a small nidus that causes **severe nocturnal pain relieved by NSAIDs**. - It is more commonly found in the **diaphysis of long bones** or posterior elements of the spine and is not primarily associated with the proximal humerus in children as a cyst. *Chondroblastoma* - A **chondroblastoma** is a rare, benign cartilaginous tumor that typically affects the **epiphysis of long bones** in adolescents and young adults. - While it can occur in the proximal humerus, it's an epiphyseal lesion, and less common than a UBC which preferentially affects the metaphysis.

Q: What is the most common type of fracture in children?

Greenstick fracture. ***Greenstick fracture*** - **Greenstick fractures** are common in children because their bones are more flexible and softer than adult bones. - The bone **bends and cracks** but does not break completely through, similar to how a young tree branch would break. *Transverse fracture* - A **transverse fracture** involves a clean break straight across the bone, which is less common in the flexible bones of children. - This type of fracture often results from a **direct blow** perpendicular to the bone's long axis. *Comminuted fracture* - A **comminuted fracture** involves the bone breaking into three or more pieces, indicating a high-energy trauma. - These are **rare in children** due to the elasticity of their bones. *Oblique fracture* - An **oblique fracture** has an angled break across the bone, typically caused by a twisting force. - While possible, it is **less common** than a greenstick fracture in children.

Q: In pediatric patients, what is the most likely consequence of untreated developmental dysplasia of the hip?

Shortening of the limb. ***Shortening of the limb*** - Untreated **developmental dysplasia of the hip (DDH)** results in the femoral head not being properly seated in the acetabulum, leading to a **proximal migration** of the femur and thus a functional **shortening of the affected limb**. - This limb length discrepancy can lead to an **uneven gait** and compensatory mechanisms in the spine and pelvis. *Genu valgum* - **Genu valgum**, or "knock-knees," is an angular deformity primarily at the **knee joint**, where the knees touch while the ankles are apart. - It is not a direct or primary consequence of untreated DDH, which primarily affects the **hip joint**. *Increased lumbar lordosis* - While **increased lumbar lordosis** can be a compensatory mechanism for various postural imbalances, it is usually a consequence of bilateral hip flexion contractures or anterior pelvic tilt, not a direct result of unilateral DDH. - In unilateral DDH, **pelvic tilt** and compensatory scoliosis are more directly associated due to limb length discrepancy. *Pelvic tilt* - **Pelvic tilt** often occurs as a **compensatory mechanism** in response to a limb length discrepancy. - While it is a common finding with untreated DDH, the **shortening of the limb** is the fundamental structural problem directly caused by the unreduced hip.

Q: Which type of fracture is associated with a fall on an outstretched hand in children?

Colles fracture. ***Colles fracture*** - A **Colles fracture** is a **distal radius fracture** that results in the distal fragment being displaced dorsally and radially, often creating a "dinner fork" deformity. - This fracture is very common in children and adults following a **fall on an outstretched hand (FOOSH)**, especially when the wrist is in extension during impact. *Galeazzi fracture* - A **Galeazzi fracture** involves a fracture of the **distal shaft of the radius** combined with a **dislocation of the distal radioulnar joint (DRUJ)**. - While it can result from a fall on an outstretched hand, this specific combination of injuries is less common than a simple Colles fracture in children and involves a different mechanism of force. *Monteggia fracture* - A **Monteggia fracture** is characterized by a fracture of the **proximal or middle third of the ulna** accompanied by a **dislocation of the radial head** at the elbow. - This injury typically occurs due to a direct blow to the forearm or an extreme pronation mechanism, and is less commonly associated with the typical FOOSH mechanism that causes Colles fractures. *Supracondylar fracture* - A **supracondylar fracture** is a fracture of the **distal humerus**, just above the elbow joint, and is the most common elbow fracture in children. - While also caused by a FOOSH injury, the force transmission in a supracondylar fracture is to the elbow, not the wrist, making it distinct from a Colles fracture.

Q: What is the most likely diagnosis for a newborn with asymmetric limb movements and a clavicle that is palpable as discontinuous upon examination?

Clavicle fracture. ***Clavicle fracture*** - A **discontinuous clavicle** on palpation is a direct sign of a fracture, which is a common birth injury. - Asymmetric limb movements can result from pain upon moving the affected arm, leading to reduced use of that limb. *Congenital muscular torticollis* - Characterized by a **sternocleidomastoid muscle mass/tightness** leading to head tilt and rotation. - While it causes asymmetric head posture, it does not typically present with a palpable clavicle discontinuity or initially with asymmetric limb movement due to pain. *Klumpke's palsy* - Involves damage to the **C8-T1 nerve roots** of the brachial plexus, leading to paralysis of the hand and wrist muscles. - Causes a characteristic **"claw hand" deformity** and is not associated with clavicle discontinuity. *Erb's palsy* - Results from injury to the **C5-C6 nerve roots** of the brachial plexus, causing weakness in the shoulder and elbow. - Presents with a **"waiter's tip" posture** (arm adducted, internally rotated, elbow extended), and is not typically associated with a clavicle fracture, though they can co-occur.

Q: A 10-year-old boy presents with a painful limp. X-rays reveal a mixed lytic and sclerotic lesion in the metaphysis of the femur. What is the most likely diagnosis?

Brodie's Abscess. **Brodie's Abscess** - This presents as a **long-standing, localized infection** (often staphylococcus) within a bone, characterized by a **mixed lytic and sclerotic lesion** on X-ray, typically in the metaphysis of long bones. - The painful limp in a 10-year-old child, along with the described radiological findings, is highly suggestive of a **chronic osteomyelitis** presenting as Brodie's abscess. *Osteosarcoma* - While it can present with a painful limp and occurs in the metaphysis of long bones in children, osteosarcoma typically shows a more **aggressive lytic and blastic pattern** with a **Codman’s triangle** or **sunburst periosteal reaction**, not solely a mixed lytic and sclerotic lesion. - It is a **malignant tumor** with rapid progression, usually presenting with more severe, constant pain. *Osteoid Osteoma* - This is a **benign bone tumor** characterized by a small lytic nidus surrounded by a large area of reactive sclerosis on X-ray. - The pain associated with osteoid osteoma is typically **worse at night** and **relieved by NSAIDs**, and the lesion description in the question (mixed lytic and sclerotic) is less specific to its characteristic "nidus." *Ewing's Sarcoma* - This is another malignant bone tumor that can cause a painful limp in children, often presenting with an **"onion skin" periosteal reaction** on X-ray, predominantly in the diaphysis of long bones, not solely a mixed lytic and sclerotic lesion in the metaphysis. - Ewing's sarcoma can also present with systemic symptoms like **fever and weight loss**, which are not mentioned in this case.

Q: A 14-year-old girl presents with a curvature of the spine that progresses with growth. Which condition is she likely to have?

Scoliosis. ***Scoliosis*** - **Scoliosis** is a sideways curvature of the spine, most commonly diagnosed in adolescents, and often progresses during periods of rapid growth. - The presentation of a **progressive spinal curvature** in a 14-year-old girl is a classic description of adolescent idiopathic scoliosis. *Kyphosis* - **Kyphosis** is an exaggerated outward curve of the thoracic spine, leading to a "hunchback" appearance. - While it is a type of spinal curvature, it is distinct from the **lateral-rotational curve** seen in scoliosis. *Lordosis* - **Lordosis** is an exaggerated inward curve of the lumbar spine, often resulting in a prominent abdomen and buttocks. - It refers to an increase in the normal anterior convexity of the lumbar spine, not a lateral curvature. *Spondylolisthesis* - **Spondylolisthesis** is a condition where one vertebra slips forward over another. - While it can cause back pain and sometimes lead to changes in spinal alignment, it is primarily a **vertebral slippage** rather than a rotational or lateral curvature of the entire spine.

Question 1

A 6-year-old child presents with a limp and limited hip abduction. An X-ray reveals flattening of the femoral head. What is the most likely diagnosis?

Accepted Answer

Legg-Calvé-Perthes disease

Answer

Slipped capital femoral epiphysis

Answer

Developmental dysplasia of the hip

Answer

Osteomyelitis

Question 2

What is the most common cause of scoliosis in pediatric patients?

Accepted Answer

Idiopathic scoliosis

Answer

Congenital spinal deformities

Answer

Neuromuscular conditions

Answer

Trauma

Question 3

A 4-year-old child presents with fever and a mass in the thigh. An X-ray shows periosteal reaction and bone destruction. What is the next best step in diagnosis?

Accepted Answer

Bone biopsy

Answer

Bone scan

Answer

Blood culture

Answer

CT Scan

Question 4

Which bone cyst is most commonly associated with the proximal humerus in children?

Accepted Answer

Unicameral bone cyst

Answer

Aneurysmal bone cyst

Answer

Osteoid osteoma

Answer

Chondroblastoma

Question 5

What is the most common type of fracture in children?

Accepted Answer

Greenstick fracture

Answer

Transverse fracture

Answer

Comminuted fracture

Answer

Oblique fracture

Question 6

In pediatric patients, what is the most likely consequence of untreated developmental dysplasia of the hip?

Accepted Answer

Shortening of the limb

Answer

Genu valgum

Answer

Increased lumbar lordosis

Answer

Pelvic tilt

Question 7

Which type of fracture is associated with a fall on an outstretched hand in children?

Accepted Answer

Colles fracture

Answer

Galeazzi fracture

Answer

Monteggia fracture

Answer

Supracondylar fracture

Question 8

What is the most likely diagnosis for a newborn with asymmetric limb movements and a clavicle that is palpable as discontinuous upon examination?

Accepted Answer

Clavicle fracture

Answer

Congenital muscular torticollis

Answer

Klumpke's palsy

Answer

Erb's palsy

Question 9

A 10-year-old boy presents with a painful limp. X-rays reveal a mixed lytic and sclerotic lesion in the metaphysis of the femur. What is the most likely diagnosis?

Accepted Answer

Brodie's Abscess

Answer

Osteoid Osteoma

Answer

Osteosarcoma

Answer

Ewing's Sarcoma

Question 10

A 14-year-old girl presents with a curvature of the spine that progresses with growth. Which condition is she likely to have?

Accepted Answer

Scoliosis

Answer

Kyphosis

Answer

Lordosis

Answer

Spondylolisthesis

Pediatric Orthopaedics — MCQs

Pediatric Orthopaedics — MCQs

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