Some health conditions, diseases, and injuries can have long-lasting effects on your bones and joints. One example of this is boutonniere deformity, when the middle joint in your finger bends inward and the outer joint bends outward. Learn more about this deformity and how to use a finger splint to lessen your symptoms and heal.
Understanding Boutonniere Deformity
Each of your fingers has several tendons that all work together, allowing the finger to bend and straighten out. Tendons run on either side and on top of your fingers. A boutonniere deformity results from an injury to your top tendon.
The injury stops the middle joint of your affected finger from straightening out, so it stays permanently bent. If left untreated, the deformity gets worse with time. The result is permanent joint damage and impaired finger function.
Causes of a Boutonniere Deformity
Several situations may lead to a boutonniere deformity. Lasting inflammation from arthritis may damage your tendons and cause permanently bent fingers. Your tendon may also be damaged by something striking the top of your finger with force. A boutonniere deformity is especially common if the force happens when your finger is already flexed at the middle joint, causing that joint to take the brunt of the blow.
If the skin on your finger breaks open, whether from force or from a cut, it may cause tendon damage. The tear looks like a buttonhole, which is "boutonniere" in French. That's how the deformity gets its name.
Symptoms of a Boutonniere Deformity
The first signs of a boutonniere deformity may show up right after an injury happens or several weeks later. When arthritis is the cause, it usually happens slowly over time.
You’ll first notice that no matter how hard you try, you can’t straighten your fingers out completely, and the tip of your finger doesn’t bend in toward the palm of your hand. You may have swelling or feel pain in the middle and outer joints.
Diagnosing a Boutonniere Deformity
When you damage your finger, a number of injuries may occur. Pain and swelling are common in finger injuries and don’t necessarily point to a boutonniere deformity. Your doctor will complete a visual assessment and then ask about your concerns.
If your doctor suspects a break, they may request an X-ray to help figure out what the next steps should be. An X-ray also shows your tendons, so the doctor can see if the top tendon is out of place and causing a boutonniere deformity.
Treating a Boutonniere Deformity
If you have any concerns about injury to the joints of your fingers, seek medical help right away. A boutonniere deformity gets worse with time and may lead to permanent damage to your fingers.
Splint. The least invasive treatment option is to use a splint to straighten your finger. This treatment option applies gentle pressure that keeps your tendon from separating as it heals. The splint also lets your outer joint to bend properly following treatment.
A younger person may need to wear the splint for 6 weeks, while an older one usually wears one for 3 weeks. Your treatment plan depends on the severity of your boutonniere deformity. Once the initial treatment is complete, your doctor may ask you to wear the splint at night while you sleep to maintain your results.
Surgery. You have two surgery options for addressing a boutonniere deformity. The first is arthrodesis, a surgery in which your doctor fuses the bones together at each joint. If a boutonniere deformity causes you severe pain, this surgery offers stability and less pain. However, it also leaves you with less flexibility in the joint.
Another surgical option is arthroplasty. This involves removing your damaged joint and replacing it with an implant. Arthroplasty is used if your condition is severe. The goal of this surgery is to relieve pain while restoring function to your fingers.
Most implants are made from silicone rubber. Around 30% of implants fail within 10 years of surgery because they can't fully duplicate natural motion. They can easily slip out of place.
Your doctor can talk to you about the pros and cons of surgery and splinting and what the best choice for you might be.