## **Core Concept**
Congenital syphilis results from the transmission of *Treponema pallidum* from mother to fetus. Musculoskeletal manifestations can occur in congenital syphilis, affecting bones and joints.

## **Why the Correct Answer is Right**
In congenital syphilis, painless joint effusions, particularly in the knees, are known as **Clutton's joints**. This condition is characterized by a painless, symmetrical synovitis leading to joint effusion, commonly seen in the knees but can also affect other joints. The exact mechanism is not fully understood, but it is believed to result from a syphilitic infection causing inflammation of the synovial membrane.

## **Why Each Wrong Option is Incorrect**
- **Option A:** While various terms might describe joint or bone manifestations in congenital syphilis, they do not specifically refer to painless effusions.
- **Option B:** Similarly, other manifestations of congenital syphilis exist, but they do not accurately describe Clutton's joints.
- **Option C:** This option might refer to other syphilis manifestations but does not accurately describe painless joint effusions.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that Clutton's joints are a classic sign of congenital syphilis. They are characterized by painless, bilateral joint effusions, most commonly in the knees. This condition typically presents in the second decade of life.

## **Correct Answer:** D. Clutton's joints