Swan Neck Deformity

Have you ever closed your fingers in a fist and then stretched them out wide? Yes, we all do and it is not a very big deal for most of us. Can you flex one finger joint and extend the other joint in the same finger? I am sure you will shout out loud saying it is impossible. However, there are a few people who have one joint in the flexed position and the other joint extended in the same finger. You will call this very abnormal and say something is amiss in the person. You are right; this is an indication of something wrong with the finger joints. This condition is called swan neck deformity of the fingers. Let us go into the details and understand this problem from the following paragraphs.

Swan Neck Deformity of the Fingers
This is a condition where the affected person is not able to fully straighten out his fingers. A person with this deformity has the middle finger joint in the hyperextended position and the joint near the fingertip in the flexed position. This is a permanent condition that is caused either by injury or inflammation. In a normal finger, ligaments, muscles and tendons help in the movement and positioning of fingers. When an injury or disease affects either of these structures it causes problems with finger alignment and function.

When you have a look at the anatomy of hand, you will understand the fingers are made up of three phalanges. There are two joints that separate the phalanges called the interphalangeal joints. Each finger joint is straightened out with the help of tendons that are called extensor tendons. They are present on the backside of the bones in the forearms. These extensor tendons become extensor hood when they reach the finger. These extensor tendons are connected to a band of tissue called ligaments. They help in balancing the motion of the finger joints. The strongest ligament is the volar plate that helps in straightening and keeping the middle joint from hyperextending. When the volar plate becomes weak or loses its ability to straighten up the joints, it leads to deformed position of fingers.

Causes
A hyperextended middle knuckle or the PIP joint and a flexed DIP joint (end knuckle), leads to the deformity. There are many causes of it, among which one of the most common causes is rheumatoid arthritis (RA). This condition causes chronic inflammation that affects the PIP joint. This stretches the volar plate causing it to become weak and stretched. Soon, the PIP joint becomes loose and bends into hyperextension. This causes the extensor tendon to shift out of balance. When this happens, the DIP joint is affected and enters into a flexion position.

Other causes of this deformity include mallet fingers. This is a condition where the volar plate loses it ability to extend and straighten the DIP joint. This leads to an imbalance with the extensor muscles, thus causing the DIP joints to enter flexion position. The ligaments on the top of the finger are torn at the distal end and they tend to apply more force, leading to hypertension of PIP joint.

Those with Ehlers-Danlos Syndrome have loose or lax joints. This causes the fingers to bend backwards and have hyperflexibility. These people tend to suffer from swan neck deformity of the fingers.

Symptoms
The physical appearance of the fingers is one of the main symptoms of the deformity. The PIP joint is in hypertension, that is, bent backwards far too much. The DIP joint is in a flexion position, that is, bent towards the palm. In severe cases, one needs to use the other hand to bend the fingers to straighten out or close the fist. The fingers get a typical swan neck shape, hence, the name.

Treatment
The treatment includes non-surgical as well as surgical options. When the PIP joint is supple and not stiff, the doctor will begin with a non-surgical treatment. This includes visit to occupational therapists who will try stretching, message, joint mobilization, etc. to correct the imbalances and restore the finger alignment.

There are splints that help in keeping the PIP joints in line. These splints prevent the fingers from moving into hypertension. Do not think these splints will make your fingers look ugly. In fact, there are new designs of splints that look like jewelry rings. You can get them in stainless steel, sterling silver and even gold. So, you can wear them as part of your deformity treatment and flaunt them as a fashion accessory.

When physical therapy and splints do not give the desired results after 6 weeks, the doctors may suggest surgery. These surgeries include soft tissue repair, PIP joint arthroplasty and finger joint fusion. The doctor will decide which surgery suits your condition and choose it receptively for treatment. After surgery, one will be required to wear braces or splints and undergo physical therapy. These therapy sessions continue for up to 3 to 5 months and will take up to 6 months for full recovery.

This is a very debilitating condition that causes loss of function of fingers. Speak to a specialist and find a treatment option that will help you overcome this finger deformity.