Swan Neck Deformity

Swan neck deformity is a condition that develops in the finger and thumb caused by a tendon imbalance where the middle joint is bent back and the end joint is bent down. When viewed from the side, the finger’s appearance is similar to a swan’s neck. In the thumb, when the tip joint bends and the middle joint does not, this is called a duck-bill thumb deformity.

Causes

Swan neck deformity is generally caused by a weakened or torn ligament in the palm side of the finger’s middle joint. The weakness is often the result of an injury or rheumatoid arthritis, which can destabilize the tissue around the joint.

Symptoms

Swan neck deformity is usually easy to identify by its resemblance to the outstretched neck of a swan. The condition can cause difficulty bending the middle joint. Stiffness and a snapping sensation are also common.

Diagnosis

Swan neck deformities are diagnosed by a physician during an exam from looking at the hands and assessing the symptoms. X-rays may also be used to rule out any other injuries or abnormalities.

Treatment

There are a number of treatment options for swan neck deformity depending on the severity of the condition. A common non-invasive option is a ring that is placed over the middle joint to correct the finger’s position. Surgery to reposition the tendons on the side of the middle joint or replacement of the arthritic joint may be necessary in severe cases.