What is Boutonniere Deformity?
The Boutonniere deformity is a medical condition where your finger bends at the middle joint (also known as the proximal interphalangeal joint or PIP) and straightens out at the end joint (also known as the distal interphalangeal joint or DIP). This situation can happen after an injury, and it’s often caused by a tear in the middle portion of a specific finger tendon, causing it to lose its ability to stretch the finger. This deformity can also happen due to a cut to the same part of the tendon and its surrounding protective layer.
Apart from physical injuries, a Boutonniere deformity could also occur as a result of burn injuries. This is especially true where circulation to the finger is limited, making the tendons more prone to tearing. Boutonniere deformities are also commonly seen in people with inflammatory arthritis, such as rheumatoid arthritis, which is a condition where your immune system mistakenly attacks your own body’s tissues, leading to inflammation in your joints.
What Causes Boutonniere Deformity?
A boutonnière deformity, or a bend in the middle joint of the finger, is usually caused by damage to the extensor tendon, the tissue that helps straighten your fingers. If this tendon gets hurt, parts of the tendon can separate, allowing the top of the closest bone in your finger to poke through the split parts of the tendon. The result looks like a buttonhole, which is where the condition got its name.
Usually, this kind of injury often happens during sports, with football and basketball being the most common sources.
Risk Factors and Frequency for Boutonniere Deformity
While ‘jam-injuries’ are a wide range of injuries related to trauma, they often result in something called ‘central slip injuries’. These can lead to a well-known condition called ’boutonniere deformities’. Furthermore, up to 50% of people suffering from rheumatoid arthritis will develop this deformity in at least one finger.
Signs and Symptoms of Boutonniere Deformity
For any injury to a finger, it’s essential to find out how the injury occurred. This is important as it will guide the choice of treatment and also help to avoid long-term problems or changes to the shape of the finger. Sometimes, a finger injury may not become obvious for several weeks. If the injury involves a cut, it’s important to clean the area well and check whether the tendons (connective tissues that join muscle to bone) are intact. The ‘Elson test’ can be used to see if there’s any damage to the tendons. This involves:
- The patient resting the injured finger along the edge of a surface like a table, with the finger bent at the middle joint (PIP joint).
- The doctor or nurse applying pressure to the middle part of the finger.
- The patient trying to straighten the finger at the PIP joint against the pressure.
- A positive sign of damage is if the end part of the finger (DIP joint) over-extends or bends back too much.
If a boutonniere deformity (a specific type of finger deformity) is caused by rheumatoid arthritis, the doctor should find out how long the patient has had symptoms, what medications they have taken previously and now, the level of pain, and how the condition impacts their ability to perform daily tasks.
Testing for Boutonniere Deformity
X-rays are useful in checking if there are any related bone fractures. They also help in identifying any breaks or disruptions in the outer layer of bones attached to the central part of the tendon. Side-view x-rays can be used to figure out the degree of bending backward.
Treatment Options for Boutonniere Deformity
The aim of treatment is to help the affected finger move normally again. There are both surgical and nonsurgical ways to treat this. One nonsurgical method is splinting, which helps keep the affected joint still to allow it to straighten out and heal. This also prevents the tendon from moving out of place. The splint is typically worn for 3 to 6 weeks, depending on the patient’s age and how severe the injury is. Patients are usually advised to continue wearing the splint at night for several more weeks. Treatment should also involve exercises to increase the strength and flexibility of the affected finger. If the injury happened during sports, the area may be taped or splinted for protection when returning to activity.
Surgery is another option if the tendon is cut or if there is a large piece of bone that has moved away from where it should be. If the condition doesn’t improve with nonsurgical treatments like splinting, surgery might be necessary. If there is a large avulsion (a piece of bone that has been ripped away), the injury can be corrected with surgical fixation using a wire or screw. If the condition has not been treated for more than three weeks, it becomes more difficult to correct.
For some people, the condition can be a long-term result of rheumatoid arthritis. Treatments for rheumatoid arthritis include disease-modifying anti-rheumatic drugs (DMARDs, which slow down the progression of the disease), biologic response modifier drugs (which work by changing the signals the immune system sends that cause tissue damage), glucocorticoids (which reduce inflammation and slow down the immune system), nonsteroidal anti-inflammatory medications (NSAIDs, which help control pain, swelling, and inflammation), and analgesics (which are used just to control pain). Each of these treatments work differently, but have a similar effect on the disease.
If nonsurgical treatments don’t work, joint replacement surgery might be necessary. Another option is joint fusion, which fuses the two joint surfaces of the affected finger together. Fusion can help relieve pain, stabilize the joint, and prevent the joint deformity from getting worse. After surgery, patients are asked to wear a splint or brace for several weeks to keep the joint straight. Physical or occupational therapy often follows splinting.
What else can Boutonniere Deformity be?
PIP joint dislocation is a common condition usually caused by trauma. It often results in a visibly noticeable deformation.
Skin contracture at the base of your finger can also result from severe burns.
Less frequently, various diseases like Hansen’s disease and epidermolysis bullosa can also cause finger contractures.
What to expect with Boutonniere Deformity
The main aim of treatment is to prevent the development of a condition known as a boutonniere deformity. Serial digital casting, a procedure where a cast is regularly applied and replaced, has been shown to be somewhat effective in achieving this. Depending on the severity of the injury, it’s not very common to see a full recovery in terms of range of motion, which refers to the full movement potential of a joint.
Possible Complications When Diagnosed with Boutonniere Deformity
Complications that can occur with or without treatment for a joint injury may vary and include:
- Stiffness in the joint that doesn’t fade away
- Re-injury or redislocation of the same joint
- Post-traumatic arthritis which is a type of arthritis induced by physical injury
- Persistent swelling
- Decreased flexibility or limited movement of the joint
Preventing Boutonniere Deformity
Doctors have an essential role in preparing their patients for the potential outcomes after injury, especially when full recovery might not be guaranteed. Patients should know that complications might happen, such as persistent stiffness in the injured area, early signs of arthritis, or a greater chance of getting injured again. This is particularly important for athletes, especially those who play sports like football and basketball, where finger injuries are more common.
Doctors should encourage their athlete patients to seek medical attention promptly if they experience ‘jam’ injuries to the fingers, which are common in these sports. It’s essential to know that delaying treatment could result in long-term problems that might limit their ability to continue playing their sport.
