**Core Concept**
Bohler's angle is a radiological parameter used to assess the integrity of the calcaneus. It is defined as the angle formed by the intersection of two lines: one drawn along the posterior edge of the posterior facet and the other along the superior margin of the posterior tuberosity. A reduced Bohler's angle is indicative of calcaneal fractures or other conditions that affect the bone structure.

**Why the Correct Answer is Right**
A reduced Bohler's angle is typically associated with calcaneal fractures, particularly those that involve the posterior facet or the posterior tuberosity. This is because the fracture disrupts the normal trabecular pattern and alters the bone's architecture, leading to a decrease in the angle. The calcaneus has a unique trabecular pattern, with denser trabeculae in the posterior facet and less dense trabeculae in the posterior tuberosity. A fracture in this area can cause a shift in the trabecular pattern, resulting in a reduced Bohler's angle.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because while fractures can affect the Bohler's angle, it is not the only condition that can do so. Other conditions such as osteoporosis or tumors may also affect the angle.
**Option B:** This option is incorrect because it is too vague and does not specifically address the Bohler's angle. Many conditions can affect the calcaneus, but not all of them will necessarily reduce the Bohler's angle.
**Option C:** This option is incorrect because it is not a condition that is specifically associated with a reduced Bohler's angle. While it may affect the calcaneus, it is not a direct cause of a reduced angle.

**Clinical Pearl / High-Yield Fact**
A reduced Bohler's angle is often associated with a "tongue" or "beak" deformity of the posterior facet, which can be visualized on a lateral radiograph of the foot. This deformity is a classic sign of a calcaneal fracture.

**Correct Answer:** C.