Take a look at your hand and straighten your fingers out. If they look crooked, there can be a few different possibilities of what may be taking place. A specific pattern that will be discussed in this article is called Swan Neck deformity.
In a swan neck finger, the tip of the finger is bent toward the palm, like in a mallet finger, while at the next joint closest to the palm there is hyperextension in the opposite direction. In most cases, this deformity is caused by disruption of the volar plate.
The volar plate is the strongest ligament on the palm side of the hand and it connects the part of the finger that is closest to the palm (proximal phalanx) to the middle part of the finger (middle phalanx). The volar plate tightens as the fingers straighten to prevent hyperextension at this joint.
With a Swan Neck deformity, the volar plate is either torn or over stretched due to trauma, injury or disease, such as Rheumatoid arthritis, and various nerve disorders, such as cerebral palsy, Parkinson’s disease, or stroke. Because the joint begins to easily bend back into hyperextension, the extensor tendons on the opposite side of the hand get out of balance, which allows the tip of the finger to get pulled downward. As the tip of the finger flexes and the middle joint hyperextends, the swan neck deformity occurs.
Treatment for a Swan Neck deformity can consist of either non-surgical or surgical options.
The non-surgical option is rehabilitation that would include strengthening, stretching, massage and joint mobilization to try to restore balance and alignment throughout the finger joints. There are also special splints that can be made to prevent the joint from hyperextending. Some of the newer splints even look like jewelry. These options work well for mild cases of Swan Neck. In more severe cases surgery may be a better option.
Surgical options include repairing the muscles or tendons that are contributing to the postural imbalance, replacing the joint that hyperextends or fusing the joint that hyperextends. Joint fusion will typically occur with the finger bent at 25-45 degrees to be most functional. After surgery, physical therapy will be needed for about 10-12 weeks.
As always, your friendly therapists at PhysioDC are here for your rehabilitative needs and are happy to help you out if you find yourself with a Swan Neck Deformity of the finger or other injuries requiring physical therapy.