**Core Concept**
Tubercular synovitis of the hip is an early stage of tuberculosis infection in the hip joint, characterized by inflammation of the synovial membrane. The synovium produces excess fluid, leading to joint effusion and potential damage to the surrounding tissues.

**Why the Correct Answer is Right**
In the early stage of tubercular synovitis, the hip joint is often spared from significant structural damage. However, the inflammation and joint effusion can lead to a characteristic deformity known as **flexion, abduction, and external rotation deformity**. This deformity occurs due to the inflammation of the surrounding muscles and ligaments, which causes the hip joint to become fixed in a flexed, abducted, and externally rotated position. The flexion deformity is often most pronounced, leading to a characteristic "frog-like" appearance of the affected hip.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the typical deformity associated with tubercular synovitis. The deformity is not typically characterized by flexion, adduction, and internal rotation.

**Option B:** This option is incorrect because it is more characteristic of a late-stage hip deformity, often seen in cases of tubercular arthritis where joint destruction is more extensive.

**Option C:** This option is incorrect because it is not a specific deformity associated with tubercular synovitis. While hip flexion can occur, it is not a characteristic feature of this condition.

**Clinical Pearl / High-Yield Fact**
It's essential to recognize that the deformity associated with tubercular synovitis can be reversible with early treatment, making prompt diagnosis and intervention crucial in preventing long-term joint damage.

**Correct Answer:** C. Flexion, abduction, and external rotation deformity.