Nonunion is common in fracture of
**Core Concept**
The question is testing the understanding of **fracture healing** and the factors that influence **nonunion**, a condition where a fracture fails to heal. Nonunion is often related to the **blood supply** and **stability** at the fracture site.
**Why the Correct Answer is Right**
Although the options are missing, typically, nonunion is common in fractures of the **scaphoid bone**, due to its fragile blood supply, especially when the fracture occurs in the proximal pole. The **tibial shaft** and **femoral neck** are other areas prone to nonunion, but the scaphoid is particularly notorious due to its **retrograde blood supply**.
**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific option, it's challenging to provide a detailed explanation, but generally, fractures in areas with a good blood supply are less likely to result in nonunion.
**Option B:** Similarly, without the option, we can't specify why it's incorrect, but areas with adequate reduction and stabilization tend to have better healing outcomes.
**Option C:** This option might be incorrect because it doesn't align with common sites known for nonunion, such as the scaphoid.
**Option D:** Again, without specifics, we can infer that areas not typically associated with nonunion would be incorrect.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that **smoking** significantly impairs fracture healing by reducing blood flow and, thus, increasing the risk of nonunion. This is a critical factor to consider in the management of fractures.
**Correct Answer:** D. Scaphoid bone.