Teardrop sign is seen in
**Core Concept**
The teardrop sign is a radiological finding seen on imaging studies, particularly in the context of trauma or pathology affecting the spine or pelvis. It refers to a specific appearance of a fragment of bone or soft tissue that resembles a teardrop shape, often indicating a fracture or dislocation.
**Why the Correct Answer is Right**
The teardrop sign is commonly associated with acetabular fractures, where a fragment of the posterior wall of the acetabulum is displaced into the pelvis, resembling a teardrop shape on radiographs. This occurs due to the displacement of the posterior wall fragment into the pelvis, often as a result of a high-energy trauma mechanism. The teardrop sign is a critical finding in the assessment of acetabular fractures, as it helps to identify the extent of the injury and guide further management.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the teardrop sign is not typically associated with fractures of the femoral neck.
**Option B:** This option is incorrect because the teardrop sign is not a characteristic finding in pelvic ring injuries.
**Option C:** This option is incorrect because the teardrop sign is not a specific feature of sacral fractures.
**Clinical Pearl / High-Yield Fact**
The teardrop sign is a classic radiological finding in acetabular fractures, and its presence should prompt a thorough evaluation of the pelvis and acetabulum to identify the extent of the injury.
**Correct Answer:** D. Acetabular fractures