This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Orthopaedics
Painless effusion in joints in Congenital syphilis are called 
Select and explain. 
A. Clutton's joint, B. Charcot's joint, C. Barton's joint, D. Chronic osteomyelitis
A: Clutton's joint
Answer: A: Clutton's joint 
Explanation: Painless synovitis at puberty in late congenital syphilis is called clutton's joint.