What is a swan-neck deformity?
Rheumatoid arthritis is a common cause of a swan-neck deformity. It’s estimated that about 50% of those with RA have this deformity. With a swan-neck deformity, the base of the finger and the outermost joint bend, while the middle joint straightens. Over time, this imbalance of the finger joints can result in the crooked swan-neck position. (True swan-neck deformity does not occur in the thumb.) A swan-neck deformity can make it almost impossible to bend the affected finger normally; it can make it difficult to button shirts, grip a glass, or pinch with the fingers.
