**Core Concept**
Supracondylar fractures of the femur are a type of complex fracture that occurs just above the knee joint. This injury is often associated with damage to the surrounding soft tissues and nerves due to the high energy mechanism of the fracture.

**Why the Correct Answer is Right**
In a supracondylar fracture of the femur, the common peroneal nerve (also known as the common fibular nerve) is frequently injured due to its anatomical location and the mechanism of the fracture. The nerve is closely related to the lateral aspect of the femur, making it susceptible to injury in this type of fracture. The common peroneal nerve is responsible for innervating the muscles of the lateral compartment of the leg, which are involved in foot and ankle movements.

**Why Each Wrong Option is Incorrect**
**Option A:** The femoral nerve is not typically injured in supracondylar fractures of the femur, as it is located more medially and is protected by the femur.

**Option B:** The sciatic nerve is a large nerve that runs down the back of the thigh, but it is not typically injured in supracondylar fractures of the femur.

**Option C:** The tibial nerve is not commonly injured in supracondylar fractures of the femur, as it is located more medially and is not as closely related to the lateral aspect of the femur.

**Clinical Pearl / High-Yield Fact**
The common peroneal nerve is also known as the common fibular nerve, and it is often referred to as the "peroneal nerve".

**Correct Answer: C. The common peroneal nerve.**