This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Orthopaedics
In which of the following deformities is the distal interphalangeal joint flexed and proximal interphalangeal joint extended? 
Select and explain. 
A. Boutonierre Deformity, B. Swan neck deformity, C. Z deformity, D. Claw hand
B: Swan neck deformity
Answer: B: Swan neck deformity 
Explanation: Boutonniere deformity: flexion contracture of PIP joint and extension of DIP jointSwan neck deformity: Hyperextension of PIP joint and flexion at DIP jointZ-deformity: radial detion of the wrist with ulnar detion of fingers(Refer: Mohindra's Fundamentals of Ohopedics, 2nd edition, pg no. 420)