<unk>  is a deformed position of the fingers or toes, in which the joint nearest the knuckle (the proximal interphalangeal joint, or PIP) is permanently bent toward the palm while the farthest joint (the distal interphalangeal joint, or DIP) is bent back away (PIP flexion with DIP hyperextension). Causes include injury, inflammatory conditions like rheumatoid arthritis, and genetic conditions like Ehlers-Danlos syndrome.
Boutonniere deformity
Sprengel's deformity
Madelung's deformity
Gibbus deformity
Tailor's bunion
Habit-tic deformity
Swan neck deformity
Rocker bottom foot