Boutonniere deformity causes symptoms and complete treatment

Boutonnière deformity (also known as “buttonhole deformity”) is a condition that affects the fingers of the hand and directly impacts both their appearance and function. It most commonly occurs due to tendon injuries or inflammatory diseases such as rheumatoid arthritis, which lead to an imbalance in the movement of the finger’s middle joint (the proximal interphalangeal joint).As the condition progresses, a noticeable bending of the middle joint develops, along with difficulty in fully straightening the finger. This can cause both functional impairment and cosmetic concerns for the patient.Although the condition may appear mild in its early stages, neglecting it can lead to permanent finger deformity. Therefore, early diagnosis and appropriate treatment are essential for restoring normal hand function, we will explore everything related to Boutonnière deformity, including its causes, symptoms, diagnosis, treatment options, and prevention.

What is Boutonnière deformity?

Boutonnière deformity is an injury affecting the extensor tendon that runs over the middle joint of the finger (the central slip of the extensor tendon). This injury leads to tearing or weakening of the tendon, causing the middle joint of the finger to bend inward, while the tip joint becomes abnormally extended. This results in noticeable dysfunction of hand movement.

❓ Does Boutonnière deformity affect one finger or multiple fingers?

It usually affects a single finger, especially after a direct injury.
However, it may affect multiple fingers in chronic conditions such as rheumatoid arthritis.

❓ Can the deformity appear suddenly or develop gradually?

It may appear suddenly after a strong injury to the finger.
Or it may develop gradually over time in chronic conditions like rheumatoid arthritis.

❓ Can the condition be ignored if it is mild?

It is not recommended to ignore it even if it appears mild.
The condition may progressively worsen and lead to a permanent deformity if not treated properly.

❓ Does it affect the thumb?

It rarely affects the thumb.
It most commonly occurs in the other fingers such as the index, middle, and ring fingers.

❓ Is wearing a splint painful?

A splint is not inherently painful.
However, it may cause mild pressure or initial discomfort.
Despite that, it is an essential part of proper treatment.

❓ Can a person return to work or study during treatment?

Yes, in most cases the patient can continue work or study normally.
However, some adjustments may be needed to avoid putting pressure on the affected finger.

❓ Is surgery dangerous?

Surgery is generally not considered dangerous.
However, it requires high precision.
Post-operative physiotherapy is essential.
Results depend greatly on the severity of the condition before surgery.

❓ What happens if the condition is not treated?

The deformity may become permanent.
There will be reduced finger mobility.
Difficulty in gripping objects and performing daily activities may develop.

❓ Can the deformity return after treatment?

Recurrence is rare in most cases.
However, it may happen if:

The underlying cause (injury or inflammation) recurs
The patient does not follow medical instructions

❓ Does it affect writing or phone use?

Yes, especially in moderate or severe cases.
It reduces fine motor control of the finger, affecting precise tasks.

❓ Does it occur in children?

It is rare in children.
However, it may occur due to sports injuries or direct falls on the hand.

❓ Is the deformity painful?

It may be painful in the early stages, especially right after injury.
In chronic cases, pain may decrease while the deformity becomes more obvious.

Causes of Boutonnière Deformity

Boutonnière deformity occurs when the middle joint of the finger (PIP joint) bends inward, while the tip joint (DIP) extends outward. The main cause is damage or dysfunction of the central slip of the extensor tendon.

Main causes:

1) Rheumatoid arthritis

One of the most common causes.
Chronic inflammation gradually weakens the tendons and surrounding ligaments.

2) Direct injuries

Tearing or rupture of the central slip tendon.
A strong blow to the finger or sudden forced bending of the joint, often seen in sports injuries.

3) Cuts and trauma

Deep cuts on the back of the finger.
Fractures or dislocation of the proximal interphalangeal joint (PIP).

4) Burns and fibrosis

Burns may lead to scar tissue formation (fibrosis),
which disrupts tendon movement and balance.

5) Neglected minor injuries

Some injuries may seem minor at first,
but neglecting them can lead to worsening and eventual visible deformity over time.

Symptoms of Boutonnière Deformity

The symptoms of this deformity clearly affect both the appearance and function of the affected finger, and include the following:

1) Visible deformity of the finger

Permanent or progressive bending of the proximal interphalangeal joint (PIP) inward.
Hyperextension or outward bending of the distal interphalangeal joint (DIP).
A characteristic “button-in-a-hole” appearance, which gives the condition its name.

2) Movement difficulty

Reduced ability to fully straighten the PIP joint.
Difficulty extending or controlling normal finger movement.

3) Pain and swelling

Pain when moving the affected joint.
Swelling around the PIP joint, more noticeable in inflammatory cases or recent injuries.

4) Joint stiffness

Gradual stiffness of the joint.
More noticeable in the morning or after periods of rest, especially in rheumatoid arthritis.

5) Functional impairment

Difficulty performing fine motor tasks such as writing or buttoning clothes.
Reduced hand strength in some cases.

Types of Boutonnière Deformity

Boutonnière deformity is not formally classified into strict medical types, but it is generally categorized based on stage, flexibility, or underlying cause.

First: Based on stage (most common classification)

1) Early (acute) stage

The injury is recent.
The PIP joint is still fully or partially extendable.
Usually caused by a partial tear of the central slip tendon.
Treatment is relatively simple, mainly splinting and physiotherapy.

2) Intermediate stage

Progressive fixed flexion of the PIP joint begins.
Clear difficulty in finger extension.
Deformity becomes more visible during movement.
Requires longer treatment and may not fully resolve without proper medical care.

3) Chronic stage

The deformity becomes fixed and clearly visible.
The PIP joint remains permanently flexed.
DIP hyperextension becomes more pronounced.
Often requires surgery or long-term rehabilitation.

Second: Based on correctability

1) Flexible (correctable) deformity

The finger can still be manually extended or corrected with treatment.
Tendons still retain some flexibility.

2) Fixed (non-correctable) deformity

The joint becomes stiff.
Fibrosis of ligaments and tissues occurs.
Often requires surgical intervention.

Third: Based on cause

1) Rheumatoid deformity

Caused by rheumatoid arthritis.
Develops gradually over time.

2) Traumatic deformity

Occurs after a direct injury to the finger.
Such as tendon rupture, fracture, or dislocation.

Diagnosis of Boutonnière Deformity

Diagnosis mainly relies on clinical examination, with additional tests when needed.

1) Clinical examination (most important)

The doctor observes:

Fixed or progressive flexion of the PIP joint.
Hyperextension of the DIP joint.
Difficulty or inability to fully extend the PIP joint.

Important test: Passive extension test

If the joint can be manually extended → flexible, treatable conservatively.
If it cannot be extended → chronic or stiff condition.

2) Medical history

Helps in diagnosis through:

Previous finger injury.
Presence of rheumatoid arthritis.
Prior pain or swelling in the joint.
Sudden or gradual symptom progression.

3) Functional assessment

Measuring range of motion.
Evaluating flexion and extension strength.
Comparing with the healthy finger.

4) X-ray

Does not directly diagnose the deformity but is used to:

Rule out fractures or dislocations.
Assess joint changes, especially in rheumatoid arthritis.
Evaluate joint erosion in chronic cases.

5) Additional tests (if needed)

Rheumatoid factor tests (RF, Anti-CCP) if rheumatoid arthritis is suspected.
MRI or ultrasound to assess the central slip tendon.

Complications of Boutonnière Deformity

Complications depend on severity, cause, and delay in treatment, ranging from mild symptoms to permanent deformity.

1) Permanent loss of finger function

Inability to fully extend the PIP joint.
Difficulty with fine tasks like writing or using a phone.
Reduced hand strength, especially if multiple fingers are affected.

2) Joint stiffness

Progressive loss of joint flexibility.
Condition may become fixed and difficult to correct.

3) Permanent finger deformity

Persistent PIP flexion.
DIP hyperextension.
Visible change in finger appearance.

4) Progression in chronic diseases

In rheumatoid arthritis, other hand joints may also be affected.
Leads to gradual functional decline if untreated.

5) Chronic pain

Pain during movement or pressure.
May become persistent in inflammatory cases.

6) Difficulty treating late cases

Delayed treatment reduces chances of non-surgical correction.
Advanced cases may require surgery or long-term rehabilitation.

Medical Treatment of Boutonnière Deformity (Medications)

Medication alone does not directly fix the deformity, because the main issue is tendon injury. However, drugs play an important role in reducing inflammation, relieving symptoms, and slowing progression.

First: Pain relievers and anti-inflammatory drugs

1) NSAIDs (Non-steroidal anti-inflammatory drugs)

Help to:

Reduce pain
Reduce swelling
Reduce inflammation

Examples:

Ibuprofen
Diclofenac
Naproxen

Notes:

Do not repair the tendon injury
Usually used short-term
May cause stomach or kidney side effects with long use

2) Paracetamol (Acetaminophen)

Used for pain relief only
Does not reduce inflammation
Preferred for mild cases or when NSAIDs cannot be used

Second: Corticosteroids

Used in severe inflammation or rheumatoid arthritis.

Forms:

Oral tablets (e.g., Prednisolone)
Local joint injections

Benefits:

Rapid reduction of inflammation
Decreases swelling in tendons and joints

Warnings:

Not for long-term use
May weaken tendons with prolonged use

Third: Disease-modifying drugs (for rheumatoid arthritis)

1) DMARDs

Examples:

Methotrexate
Hydroxychloroquine
Sulfasalazine

Benefits:

Slow or stop joint and tendon damage
Prevent deformity progression

2) Biologic drugs

Used in advanced or resistant cases.

Examples:

TNF inhibitors such as Etanercept and Adalimumab

Benefits:

Precisely reduce immune system activity
Significantly slow disease progression

Fourth: Supportive medications

Vitamin D for bone health
Calcium if needed
Muscle relaxants in some cases

Important note

Medications cannot repair a torn tendon or correct finger shape.
However, they help to:

Reduce inflammation
Slow disease progression
Protect other joints from damage

Surgical Treatment of Boutonnière Deformity

Surgery is indicated in Boutonnière deformity when the condition is chronic, fixed, or when conservative treatment (such as splinting and physiotherapy) fails. The goals of surgical intervention are:

Restoring balance between the finger tendons
Correcting flexion of the proximal interphalangeal joint (PIP)
Improving hand function as much as possible, and sometimes appearance

First: Soft Tissue Release

These procedures are used in moderate or partially flexible cases.

1) Lateral band release

Concept:
Releasing the lateral bands that have shifted dorsally and contribute to PIP flexion.

Procedure:

A small surgical incision is made on the back of the finger
The lateral bands are released and repositioned
They are fixed in the correct anatomical position

Goal:

Restore extension of the PIP joint

2) Capsulotomy (joint capsule release)

Concept:
Used when there is joint stiffness or fibrosis.

Procedure:

Opening the PIP joint capsule
Removing adhesions and fibrotic tissue
Restoring joint mobility as close to normal as possible

Second: Tendon Reconstruction

3) Central slip repair

Concept:
Repairing or reconstructing the damaged extensor tendon.

Procedure:

Surgically exposing the tendon
Suturing it if partially torn
Using a tendon graft if necessary

4) Tendon transfer

Concept:
Using a healthy tendon to replace the damaged one.

Procedure:

Harvesting part of a nearby healthy tendon
Redirecting it to perform the function of the damaged tendon
Fixing it to the PIP joint

Third: Tendon Balancing Procedures

5) Lateral band relocation

Concept:
Repositioning the lateral bands from the back to the front of the joint.

Procedure:

Detaching the lateral bands
Moving them to the anterior side of the joint
Fixing them in place, usually with splint support after surgery

6) Tendon tightening or lengthening

Concept:
Adjusting tendon tension to restore balance between flexion and extension.

Fourth: Arthrodesis (Joint Fusion)

Used in severe or non-repairable cases.

7) Joint fusion

Procedure:

Removing joint surfaces
Fixing bones with screws or wires

Result:

Complete loss of joint movement
But a straight and more functional finger position

Fifth: Postoperative Care

8) Splinting

The PIP joint is immobilized in an extended position
Usually for 4–6 weeks or longer depending on the case

9) Physiotherapy

Prevents stiffness
Gradually restores movement
Strengthens tendons and surrounding muscles

Choosing the surgical method

Condition	Suitable surgery
Early and flexible	Tendon repair + splinting
Moderate	Soft tissue release + tendon repositioning
Chronic but mobile	Tendon reconstruction
Severe and fixed	Joint fusion

Exercise Treatment for Boutonnière Deformity

Exercises are an important part of treatment, especially in early stages, after splint removal, or after surgery. However, exercises alone cannot repair a torn tendon. They help restore movement, prevent stiffness, and improve finger function.

Important before starting exercises

In early cases, splinting in PIP extension is usually required
Exercises should only begin after medical approval

Goals of therapy exercises

Strengthen the central slip tendon
Prevent stiffness of the PIP joint
Improve finger range of motion
Restore balance between PIP and DIP joints

Therapeutic exercises

1) Passive PIP extension

Gently straighten the finger using the other hand
Hold for 5–10 seconds
Repeat 10–15 times, 3–5 times daily
Benefit: Prevents stiffness and improves flexibility

2) Isometric extension exercise

Place finger on a flat surface
Try to lift it slightly without strong movement
Hold for 5 seconds
Repeat 10 times, 2–3 times daily
Benefit: Strengthens extensor tendon safely

3) DIP flexion exercise

Bend only the fingertip joint
Keep PIP as straight as possible
Benefit: Restores tendon balance and reduces DIP hyperextension

4) Assisted extension

Support finger movement using the other hand or elastic band
Benefit: Gradually improves range of motion

5) Light resistance exercise

Use therapy putty or soft resistance bands
Try to extend the finger against resistance
Benefit: Strengthens muscles and tendons

6) Stretching

Gently extend the finger upward
Hold for 15–30 seconds
Repeat regularly
Benefit: Improves flexibility and reduces stiffness

Important guidelines

Avoid strong pain or excessive force
Progress gradually
Stop if pain or swelling increases
Consistency is more important than intensity

Duration of treatment

Usually 4–8 weeks or longer depending on severity
Best results occur when combined with splinting and physiotherapy

Prevention of Boutonnière Deformity

Prevention focuses on protecting the central slip tendon and avoiding injuries or conditions that weaken it.

First: Preventing injuries

1) Avoid direct finger trauma

Be careful during sports like basketball, volleyball, and football
Use protective equipment when needed
Avoid forced bending of the finger backward

2) Use protective devices

Finger splints during sports
Buddy taping (taping fingers together)
Protective gloves in contact sports

3) Proper handling of minor injuries

Do not ignore finger pain or sprains
Apply cold compresses in the first 24–48 hours
See a doctor if symptoms persist

Second: Preventing complications after injury

4) Early treatment

Immobilize the finger if tendon injury is suspected
Use splints when necessary
Follow treatment instructions carefully

Neglect is a major cause of permanent deformity.

5) Early physiotherapy

Gentle exercises under supervision
Maintain tendon flexibility
Prevent joint stiffness

Third: Prevention in joint diseases (especially rheumatoid arthritis)

6) Control rheumatoid arthritis

Follow prescribed medications (e.g., methotrexate)
Regular medical follow-up
Reduce inflammatory flare-ups

7) Reduce joint stress

Use assistive tools to reduce hand strain
Distribute pressure across the whole hand

Fourth: Daily preventive habits

8) Maintain finger flexibility

Do light finger exercises daily
Avoid prolonged finger flexion positions