Question

which deformity is described as hyperextension of the distal interphalangeal joint and hyperflexion of the proximal interphalangeal joint?
haygarth
swan neck
boutonniere
mallet

Explanation:

Swan - Neck deformity is characterized by hyperextension of the distal interphalangeal joint and hyperflexion of the proximal interphalangeal joint. Haygarth nodes are bony enlargements at the DIP joints. Boutonniere deformity has hyperflexion of DIP and hyperextension of PIP. Mallet finger is a flexion - deformity of the DIP joint due to extensor tendon injury.

Answer:

B. Swan Neck