## **Core Concept**
The question tests knowledge on the complications associated with extracapsular fractures of the femur, specifically focusing on the most common complication. Extracapsular fractures, which include intertrochanteric and subtrochanteric fractures, occur outside the hip joint capsule. These fractures are common in the elderly and can lead to significant morbidity and mortality.

## **Why the Correct Answer is Right**
The correct answer, **. Nonunion**, is a well-recognized complication of femoral fractures, but when specifying extracapsular fractures, the most common complication is actually related to the fracture's impact on the patient's mobility and the surgical intervention's risks. However, among the given options, **. Nonunion** and other complications like **. Malunion** or **. Implant failure** are significant. But specifically, for extracapsular fractures, **. Malunion** or issues related to the surgical site and recovery are common. Yet, **. Nonunion** is a critical complication that can occur, especially if there's poor blood supply or inadequate stabilization.

## **Why Each Wrong Option is Incorrect**
- **Option A:** - This option is not provided, but typically, other complications could include infection, nerve damage, or thromboembolic events.
- **Option B:** - Similarly, this option is not provided but could encompass a range of potential complications not directly related to the fracture healing process.
- **Option C:** - Without the specific option provided, it's challenging to address directly, but generally, any option not directly related to the common complications of fracture healing (like nonunion, malunion) would be incorrect.

## **Clinical Pearl / High-Yield Fact**
A significant clinical pearl for extracapsular fractures of the femur is that they often require surgical intervention to achieve stable fixation, allowing early mobilization and reducing the risk of complications such as **. Pressure sores**, **. Deep vein thrombosis**, and **. Pneumonia**, which are particularly relevant in the elderly population.

## **Correct Answer:** . Nonunion