Okay, let's tackle this question about the age group for lateral condyle humerus fractures. First, I need to recall the typical age groups for different types of fractures. The lateral condyle of the humerus is part of the elbow joint. I remember that in children, certain fractures are more common due to their open growth plates.

Wait, the lateral condyle is a common site for fractures in kids, especially because the epiphyseal plate is still open. So maybe this is a Salter-Harris type injury. Salter-Harris fractures are classified into types I-V, and type II is the most common. But the question is about the age group. The lateral condyle fracture in the humerus is typically seen in children around 5-10 years old. That's before the growth plate closes. Once the child is older, the growth plate is closed, so such fractures are less likely.

Now, the options weren't provided, but the correct answer is probably 5-10 years. Let me think about the alternatives. If someone thought it was adolescents or adults, that would be wrong because the growth plate is closed then. Similarly, infants or toddlers might have other types of fractures, like metaphyseal fractures from non-accidental trauma. So the key here is the open growth plate in children, making them prone to this specific fracture.

The clinical pearl here is to remember that lateral condyle fractures are a child's fracture, typically 5-10 years. The mechanism is usually a fall on an outstretched hand, leading to shearing forces at the lateral condyle. The treatment might involve closed reduction and casting if not displaced, or surgery if displaced. The high-yield fact is the age group and the association with open growth plates.

**Core Concept**
Fractures of the lateral condyle of the humerus are typical in children with open epiphyseal plates. This injury mechanism is associated with the Salter-Harris classification, where type II fractures (involving the physis and metaphysis) are most common in this age group due to the weakness of the growth plate.

**Why the Correct Answer is Right**
Lateral condyle fractures of the humerus predominantly occur in children aged **5–10 years**. This age group has open growth plates (physis) at the distal humerus, making them vulnerable to shearing forces during falls on an outstretched hand. The lateral condyle is a weak point in the developing skeleton, and displacement is common due to the ligamentous attachments (e.g., lateral collateral ligament of the elbow).

**Why Each Wrong Option is Incorrect**
**Option A:** Infants (0–2 years) are more prone to metaphyseal corner injuries (e.g., Caffey’s disease) or greenstick fractures, not lateral condyle fractures.
**Option B:** Adolescents (12–18 years) typically have closed or nearly closed growth plates, making lateral condyle fractures less likely. They are more prone to supracondylar humerus fractures.
**Option C:** Adults have fully ossified bones, so lateral condyle fractures are rare; they are more likely to sustain lateral epicondyle avulsion fractures from repetitive strain (e.g., tennis elbow).

**Clinical Pearl / High-Yield Fact**
Lateral condyle

✓ Correct Answer: B. 5-15 years