What is a boutonniere deformity?
A boutonniere deformity is a condition that affects the joints in one of your fingers. It causes the middle joint of your finger to bend in, and the outermost joint to bend out. It’s also called a central slip injury.
It’s often caused by rheumatoid arthritis. Other possible causes include:
There are both surgical and nonsurgical treatment options for treating boutonniere deformities, depending on the severity.
Boutonniere deformity vs. swan neck deformity
Before diving into the different treatment options, it’s important to know the difference between a boutonniere deformity and swan neck deformity. While they’re similar, they do have a few key differences.
In the swan neck deformity, the base of your finger, not the middle joint, bends in or flexes toward your hand. The middle joint is straightened or extended outward, while the outermost joint bends or flexes toward the palm. Like boutonniere deformities, swan neck deformities are often caused by rheumatoid arthritis.
Mild cases of boutonniere deformity usually don’t require surgery.
The most common treatment for boutonniere deformity involves stabilizing your finger with a splint that rests on the middle joint. The splint creates pressure to straighten and immobilize the finger. If the deformity was caused by an injury, wearing a splint can also help to straighten out the tendon and take tension off it as it heals.
You’ll likely need to wear the splint continuously for three to six weeks. After that, you may need to wear it at night for a few weeks.
A boutonniere deformity can affect your finger’s range of motion and flexibility. Your doctor may recommend doing some exercises to help strengthen the affected finger, such as:
- raising and lowering your finger at the knuckle
- bending and straightening the tip of your finger
If your boutonniere deformity is due to rheumatoid arthritis or osteoarthritis, wearing a splint and doing strengthening exercises may not be enough. You doctor may instead prescribe medication, including corticosteroid injections to reduce inflammation and swelling. They might also instruct you to wear a splint while taking medication.
In some cases, boutonniere deformities require surgery. This is more likely in cases caused by advanced rheumatoid arthritis or severe injuries.
There are several different approaches for surgically treating a boutonniere deformity, including:
- cutting and releasing tendons
- cutting and sewing together damaged tendons
- using a piece of tendon from another area
- using wire or small screws to straighten the joints
It generally takes about 12 weeks to recovery from these types of surgery, and you may have limited use of your affected hand during that period.
A boutonniere deformity is a fairly common complication of rheumatoid arthritis, osteoarthritis, and finger injuries. It’s often treated by wearing a splint when caught early. In more severe cases, you may need surgery to repair the tendons in your finger or straighten the middle joint.