**Question:** Most common complication of Coles fracture is:

A. Non-union
B. Malunion
C. Tuberculosis
D. Dislocation

**Correct Answer:** D. Dislocation

**Core Concept:**
Coles fracture, also known as a Salter-Harris type II fracture, is a fracture that occurs in the growth plate of the distal fibula in children. This type of fracture affects the physis, where the growth cartilage is replaced by bone. The most common complication of a Coles fracture is dislocation, particularly when the fracture is not reduced and stabilized properly.

**Why the Correct Answer is Right:**
When a Coles fracture is not reduced adequately, the displaced fragments can lead to a dislocation at the affected joint. The displacement can cause instability and inability to bear weight on the injured limb, leading to pain, swelling, and limited mobility. Inadequate reduction can also result in malunion or non-union, but these complications are less common compared to dislocation.

**Why Each Wrong Option is Incorrect:**
A. Non-union: This complication occurs when the fracture fails to heal despite a reasonable attempt at treatment. Coles fracture is usually associated with a good prognosis due to its relatively small bone and the presence of the growth plate, which promotes healing.

B. Malunion: Malunion in Coles fracture refers to the fracture healing in an abnormal position, affecting the alignment of the bone. However, malunion is less common compared to dislocation when the fracture is not reduced appropriately.

C. Tuberculosis: Tuberculosis is not directly related to Coles fracture and would be a complication associated with a tuberculosis infection in the affected area.

**Clinical Pearl:**
Proper management of Coles fracture includes reduction and immobilization to prevent complications. In the event of a dislocation or malunion, prompt reduction under anesthesia and fixation with an appropriate splint or cast is essential to ensure a successful outcome.