**Core Concept**
Gissane's angle is an important radiological landmark in the evaluation of intra-articular fractures of the calcaneum, reflecting the angle between the posterior facet and the anterior process of the calcaneus. It is crucial for assessing the severity and guiding the management of these fractures. The angle is measured on a lateral radiograph of the foot or ankle.

**Why the Correct Answer is Right**
The normal Gissane's angle is approximately 120-145 degrees, but in the context of intra-articular calcaneal fractures, an increase in this angle suggests a more severe displacement of the fracture fragments, indicating a worse prognosis and potentially requiring more aggressive treatment. Understanding the significance of Gissane's angle is vital for orthopedic surgeons in planning surgical interventions.

**Why Each Wrong Option is Incorrect**
**Option A:** This choice is incorrect because it does not accurately represent the normal range or the significance of Gissane's angle in the context of calcaneal fractures.
**Option B:** Similarly, this option does not correctly reflect the angle's measurement or its implications for fracture management.
**Option C:** This choice is also incorrect as it fails to provide a relevant or accurate description of Gissane's angle.
**Option D:** This option is incorrect as it is not the correct answer choice provided for the question.

**Clinical Pearl / High-Yield Fact**
Remembering that an increased Gissane's angle in intra-articular calcaneal fractures often correlates with a more complex fracture pattern and potentially poorer outcomes is crucial. This knowledge aids in the prompt recognition and appropriate referral of such cases for specialized orthopedic care.

**Correct Answer:** Correct Answer: B. 120-145 degrees