Definition

Boutonnière deformity (BD) prevents you from straightening your finger. The disorder affects the finger’s system of tendons. The tendons allow you to flex and straighten your finger.

Tendons in Finger

Finger Tendon

Copyright © Nucleus Medical Media, Inc.

Causes

In BD, the tendon on the top of the finger (called the central slip) is torn or cut from the other tendons. This creates a tear that resembles a buttonhole (or boutonnière in French). The middle joint is forced down and the fingertip bends back. The tendons on this part of the finger are flat and thin. They are prone to injury. If you have BD in the thumb, it affects a joint called the metacarpophalangeal (MCP).

BD can be caused by:

    
  • A powerful blow to the finger
  • A cut to the finger’s central slip
  • An injury to the middle finger joint (called the proximal interphalangeal [PIP] joint)
  • A severe burn on the hand
  • Risk Factors

    These factors increase your chance of developing BD:

        
  • Having rheumatoid arthritis or Dupuytren’s contracture
  • Participating in rough sports, especially those involving catching and throwing balls (eg, football, basketball)
  • Tell your doctor if you have any of these risk factors.

    Symptoms

    If you have any of these symptoms, do not assume it is due to BD. These symptoms may be caused by other conditions. Tell your doctor if you have any of these:

        
  • Pain and swelling on the top of the finger’s middle joint (the PIP joint)
  • Inability to straighten finger at the middle joint
  • Sign of injury (such as fracture or dislocation) to the PIP joint
  • Sign of injury (such as fracture or dislocation) to the MCP joint
  • Diagnosis

    Your doctor will ask about your symptoms and medical history. A physical exam will be done, paying close attention to:

        
  • Muscle strength
  • Joint damage
  • Range of motion
  • Presence of swelling
  • Evidence of infection
  • Tenderness in the finger
  • An x-ray may be done to see if you have a fracture.

    Treatment

    Talk with your doctor about the best treatment plan for you. Treatment options include the following:

    Medication

    Your doctor may recommend the following medications:

        
  • Corticosteroids—to reduce inflammation
  • Nonsteroidal anti-inflammatory drugs (NSAIDS)—to reduce pain and inflammation
  • Nonsurgical Approaches

    For milder cases, the treatment is nonsurgical and may involve:

        
  • Splinting     
  • Applied to the middle joint to fully extend it
  • Used for 3-6 weeks
  • Stretching and strengthening exercises
  • Other techniques: massage, ultrasound therapy, electrical stimulation
  • If your finger does not improve, you may need surgery.

    Surgery

    Surgery is needed in severe cases. For example, when the tendon is cut or when the deformity has lasted a long time. Surgery generally does not return your finger to the way it was working before the injury. But, you may have some improvement. After surgery, you will have to do exercises to strengthen the finger.

    Prevention

    To help reduce your chance of getting BD, take the following steps:

        
  • Wear the proper equipment when playing sports.
  • If you have rheumatoid arthritis, ask you doctor about ways to protect your joints.