Deformity in anterior dislocation of hip is
**Core Concept**
The question is testing the understanding of the anatomical and clinical consequences of anterior dislocation of the hip. Anterior dislocation of the hip occurs when the femoral head is displaced anteriorly out of the acetabulum, often due to a combination of flexion, abduction, and external rotation of the hip.
**Why the Correct Answer is Right**
In an anterior dislocation, the femoral head is displaced anteriorly, resulting in a characteristic deformity. This deformity is due to the femoral head being positioned in front of the acetabulum, which causes the leg to appear shorter and more flexed than the unaffected side. The deformity is often described as a "flexion, abduction, and external rotation" deformity. This is due to the femoral head being displaced anteriorly and the hip being in a position of flexion, abduction, and external rotation.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because posterior dislocation of the hip is characterized by a different deformity, often described as a "flexion, internal rotation, and adduction" deformity.
* **Option B:** This option is incorrect because the deformity in anterior dislocation of the hip is not characterized by a posterior displacement of the femoral head.
* **Option C:** This option is incorrect because the deformity in anterior dislocation of the hip is not characterized by a medial displacement of the femoral head.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that the deformity in anterior dislocation of the hip is characterized by a "flexion, abduction, and external rotation" deformity, which is often referred to as the "turtle sign" due to the appearance of the leg resembling a turtle's leg.
**Correct Answer: C. Flexion, abduction, and external rotation deformity.**