A Swan Neck Deformity is a deformity of the finger in which the middle joint is bent back more than normal, and the tip of the finger is bent down. Sometimes, this deformity can be caused by an injury. Other times, it can happen over time due to a condition such as rheumatoid arthritis.
The odd bending of the finger is usually due to a tear of a ligament in the middle joint of the finger. Sometimes, the tendon is torn. It causes the tendon to become weak. Eventually, the ability of the tendons to straighten the joint becomes lessened, causing the bending. Here are some signs that you have a Swan Neck Deformity: