**Question:** In class III Ellis fracture

A. Disruption of bone cortex with fracture line passing through the medulla
B. Disruption of bone cortex with fracture line passing through the medulla and involvement of articular surface
C. Disruption of bone cortex with fracture line passing through the medulla and involvement of articular surface and posterior cortex
D. Disruption of bone cortex with fracture line passing through the medulla and involvement of articular surface

**Correct Answer:** D. Disruption of bone cortex with fracture line passing through the medulla and involvement of articular surface

**Core Concept:** Class III Ellis fracture refers to a fracture that involves the cortical bone, medulla, and articular surface, with an extension into the posterior cortex. This classification system categorizes fractures based on the extent of the damage to the bone cortex, medulla, and articular surface.

**Why the Correct Answer is Right:**

Class III Ellis fractures are a severe type of fracture that involves the disruption of the bone cortex, medulla, and articular surface, with extension into the posterior cortex. This classification helps in understanding the extent of the injury, guiding treatment options, and predicting the prognosis.

**Why Each Wrong Option is Incorrect:**

A. This option describes a fracture with disruption of the bone cortex but does not mention the involvement of the medulla or articular surface, which distinguishes it from the correct answer.
B. This option includes the involvement of the articular surface, but omits the posterior cortex extension, making it an incomplete description of a Class III Ellis fracture.
C. This option includes the involvement of the articular surface and posterior cortex, but leaves out the medulla, which is also crucial in distinguishing this fracture type from the correct answer.
D. This option correctly describes a fracture with disruption of the bone cortex, medulla, and articular surface, but omits the posterior cortex extension, which is a crucial aspect of a Class III Ellis fracture.

**Clinical Pearl:** Class III Ellis fractures require prompt medical attention and appropriate treatment to prevent complications such as malunion, non-union, or post-traumatic arthritis. A thorough understanding of fracture classifications, including the Ellis classification, is essential for accurate diagnosis, treatment planning, and patient prognosis.