**Question:** The type of fracture which occurs in infants and children is:

A. Salter-Harris fracture
B. Greenstick fracture
C. Closed fracture
D. Open fracture

**Core Concept:**

A Salter-Harris fracture is a specific type of pediatric fracture that occurs due to the differential growth rates of the bone. In children, the growth plates (epiphyses) are more vulnerable than the rest of the bone, leading to a specific pattern of fracture. The Salter-Harris classification system categorizes pediatric fractures based on the relationship between the fracture line and the growth plate.

**Why the Correct Answer is Right:**

A Salter-Harris fracture is the correct answer because it is the type of fracture that occurs in infants and children. The Salter-Harris classification divides pediatric fractures into six categories based on the relationship between the fracture line and the growth plate. In a Salter-Harris type I fracture, the fracture line passes through the growth plate, while in type II, the fracture extends through the growth plate and a portion of the epiphysis.

**Why Each Wrong Option is Incorrect:**

B. A greenstick fracture is another type of pediatric fracture but refers specifically to a type of bending fracture where the bone remains intact on one side without any significant angulation or shortening. It occurs due to the differential growth rates between the epiphysis and diaphysis. Although related, greenstick fractures do not directly answer the question about the type of fracture in infants and children, so it is incorrect.

C. A closed fracture refers to a type of fracture where the bone remains enclosed by the skin and soft tissues, without any penetration or damage to the skin. This option is relevant to pediatric fractures but does not specify the type of fracture unique to infants and children.

D. An open fracture is a fracture where the bone is exposed through the skin, often resulting from high-energy trauma. This type of fracture is not specific to infants and children and does not address the question about the type of fracture in this age group.

**Clinical Pearl:**

Greenstick fractures are a common type of pediatric fracture, and understanding their pathophysiology is essential for diagnosing and managing these injuries. Pediatric fractures often involve the epiphysis, while in adults, fractures typically occur in the diaphysis. Pediatric fractures are typically caused by a low-energy trauma, such as a fall onto an outstretched hand, while adult fractures often result from high-energy trauma.