**Question:** A 10-year-old boy presenting with a cubitus varus deformity and a history of trauma 3 months back on clinical examination, has the preserved 3 bony point relationship of the elbow. The most probable diagnosis is

A. Epiphysiolysis
B. Salter-Harris fracture type II
C. Salter-Harris fracture type III
D. Salter-Harris fracture type IV

**Correct Answer:** D. Salter-Harris fracture type IV

**Core Concept:** Cubitus varus deformity is a term used to describe a type of elbow fracture in children where the radial head fractures through the growth plate of the radius, leading to a deformity characterized by a valgus angulation of the distal part of the radius. In this case, the preserved 3 bony point relationship of the elbow indicates that the radial head fracture has occurred through the growth plate of the radius.

**Why the Correct Answer is Right:** The correct answer, Salter-Harris fracture type IV, refers to a fracture that occurs in the distal radial epiphysis involving the radial head and neck, leading to cubitus varus deformity. This type of fracture occurs in the growth plate of the radius, resulting in a valgus angulation of the distal part of the radius. Although the other options involve Salter-Harris fracture types, they do not account for the preserved 3 bony point relationship of the elbow, which is a crucial clue to identify the correct diagnosis.

**Why Each Wrong Option is Incorrect:**

A. Epiphysiolysis: This refers to a separation of the epiphysis from the shaft of a long bone, usually due to a trauma. It doesn't describe the specific fracture pattern in this case.

B. Salter-Harris fracture type II: This type of fracture involves the diaphysis (shaft) of the radius, not the epiphysis (growth plate).

C. Salter-Harris fracture type III: This fracture type involves the diaphysis of the radius and ulna, not the epiphysis.

**Clinical Pearl:** The preserved 3 bony point relationship of the elbow in a cubitus varus deformity helps differentiate between various fracture types and guides towards the correct diagnosis. It is essential for clinicians to consider the age of the patient, mechanism of injury, and the preserved 3 bony point relationship to accurately diagnose the fracture type and initiate appropriate management.