## **Core Concept**
The angle of Gissane, also known as the angle of inclination, is a significant radiological parameter used in orthopedics. It is specifically associated with the **talus bone** in the foot, particularly relevant in the assessment of talar fractures.

## **Why the Correct Answer is Right**
The angle of Gissane is measured on a lateral radiograph of the ankle and is defined by the intersection of two lines drawn through the talar dome. One line is drawn along the superior surface of the talar dome, and the other line is drawn along the lateral talar facet. Normally, this angle ranges approximately from 130° to 150°. It is crucial for assessing the integrity of the talar dome and the subtalar joint. The angle helps in evaluating the severity and potential displacement of talar fractures.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because, although several bones have specific angles used in orthopedic assessment (e.g., the angle of Boehler for the calcaneus), the angle of Gissane is not associated with this bone.
- **Option B:** This option is incorrect because the angle of Gissane is not related to this bone; it's specifically associated with the talus.
- **Option D:** This option is incorrect because, similar to options A and B, the angle of Gissane does not pertain to this bone.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that an increased angle of Gissane may indicate a **talar fracture**, particularly a fracture through the talar neck or body. This can disrupt the blood supply to the talus, potentially leading to avascular necrosis. Thus, accurate measurement and interpretation of this angle are critical in the management of ankle and foot injuries.

## **Correct Answer:** C. Talus.