**Core Concept**
Tillaux's sign is a clinical finding associated with a specific pathological condition. It refers to the presence of a characteristic swelling or deformity in the region of the ankle, resulting from a particular type of fracture.

**Why the Correct Answer is Right**
Tillaux's sign is seen in a type of fracture known as a "Tillaux fracture," which is a bimalleolar equivalent fracture of the distal fibula. This fracture occurs when the fibula is broken near the ankle joint, and the surrounding soft tissues become swollen and inflamed. The presence of Tillaux's sign is a clinical indicator of this type of fracture. The mechanism of injury typically involves a forced external rotation of the foot, which results in the fracture of the distal fibula.

**Why Each Wrong Option is Incorrect**
* **Option A:** Not relevant to Tillaux's sign, as it is not associated with a similar type of fracture or injury.
* **Option B:** Not correct, as it is a different type of fracture that affects the tibia and fibula, but does not involve the same clinical sign.
* **Option C:** Not relevant, as it is a different type of ankle injury that does not involve a fracture of the distal fibula.

**Clinical Pearl / High-Yield Fact**
It is essential for clinicians to recognize Tillaux's sign in patients with ankle injuries, as it is a critical indicator of a potential Tillaux fracture. This knowledge can help guide further diagnostic evaluation and treatment.

**Correct Answer:** C.