Pipkin fracture is defined as
**Core Concept**
A Pipkin fracture is a classification of femoral neck fractures that involves the femoral head. It is an important concept in orthopedic trauma, as it has implications for treatment and prognosis.
**Why the Correct Answer is Right**
The correct answer is D. Pipkin fractures are classified into four types based on the location and extent of the fracture. Type I involves a fracture of the posterior femoral neck, Type II involves a fracture of the anterior femoral neck, Type III involves a fracture of the femoral head with a posterior displacement of the head, and Type IV involves a fracture of the femoral head with a combination of posterior and anterior displacement. The classification helps in determining the best treatment approach, which may involve closed reduction and internal fixation, open reduction and internal fixation, or even arthroplasty.
**Why Each Wrong Option is Incorrect**
**Option A:** This is incorrect because a Pipkin fracture specifically refers to a fracture of the femoral neck involving the femoral head, not a fracture of the femoral shaft.
**Option B:** This is incorrect because a Garden classification is used to describe femoral neck fractures, not a Pipkin fracture.
**Option C:** This is incorrect because a Colles fracture is a type of fracture that occurs at the distal radius, not a fracture of the femoral neck.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the Pipkin classification is specific to femoral neck fractures involving the femoral head, and understanding this classification is crucial for determining the best treatment approach for these complex fractures.
**Correct Answer: D. Pipkin fracture of the femoral neck.**