**Question:** The commonest hip injury in the elderly patients is -

A. Femoral neck fracture
B. Trochanteric fracture
C. Pelvic fracture
D. Acetabular fracture

**Correct Answer:** D. Acetabular fracture

**Core Concept:** Hip fractures are a significant public health issue, particularly in the elderly population, due to their association with increased morbidity, mortality, and decreased quality of life. Hip fractures are classified into two main categories: femoral neck fractures and acetabular fractures.

**Why the Correct Answer is Right:** Acetabular fractures are a subset of hip fractures that involve the hip joint socket (acetabulum) and are more complex injuries compared to femoral neck fractures. These fractures are mainly caused by high-energy trauma, such as motor vehicle accidents or falls from height, which are common in the elderly population. Acetabular fractures often involve multiple fragments and can lead to significant displacement and instability of the hip joint.

**Why Each Wrong Option is Incorrect:**

A. Femoral neck fractures (also known as subtrochanteric fractures) occur in the femoral neck region, which is a separate category from acetabular fractures. These fractures are less common in elderly patients than acetabular fractures.

B. Trochanteric fractures occur in the greater trochanter region, which is a different type of hip fracture from acetabular fractures. These fractures are not as common in elderly patients as acetabular fractures and do not specifically address the issue of the hip joint socket.

C. Pelvic fractures encompass fractures involving the entire pelvis, including the acetabulum and other pelvic bones. While pelvic fractures can occur in elderly patients, they do not specifically address the hip joint socket and are less specific than acetabular fractures in terms of targeting the hip joint.

**Clinical Pearl:** Acetabular fractures represent a significant clinical challenge due to their impact on the stability and function of the hip joint, leading to impaired mobility and increased morbidity in elderly patients. Early recognition and management are crucial for optimal outcome and minimizing complications like avascular necrosis, septic arthritis, and non-union.