Children's Hospital Colorado

Finger/Thumb Hypoplasia or Aplasia

What is finger/thumb hypoplasia or finger/thumb aplasia?

  • Finger/thumb hypoplasia is when a baby is born with a finger or thumb that is not developed completely (it is usually small in size).
  • Finger/thumb aplasia is when a baby is born without a finger or thumb (it is missing).
  • The condition may or may not involve the other structures of the finger/thumb (bones, tendons, ligaments, muscles, joints and nerves).

What causes finger/thumb hypoplasia or aplasia?

Doctors do not know why finger/thumb hypoplasia or aplasia occurs, but they do know that it is often associated with specific syndromes and other hand differences.

How is finger/thumb hypoplasia or aplasia diagnosed?

Finger/thumb hypoplasia or aplasia is diagnosed by examination, usually just after birth. Often, X-rays will be ordered to look at the bones of the thumbs/fingers. The baby's doctor may order other tests to check for associated syndromes.

How is finger/thumb hypoplasia or aplasia treated?

Treatment of finger/thumb hypoplasia or aplasia varies and may include surgery.

It is important to take into account the child's overall health, medical history and whether surgery will improve how the hand works.

Infants and children born with these hand differences learn to use their hands to pinch and grasp using the structures of the hand they do have. Some activities are still harder for these children to perform.

If surgery is recommended:

  • It is usually reconstructive (rebuilding or remaking) surgery.
  • Surgery may be done to make the web space (skin between the fingers or thumb and fingers) less tight. Sometimes a skin graft is needed.
  • Surgery may be performed on bones, tendons, ligaments, muscles, joints and/or nerves.
  • The surgery will be done in the operating room under general anesthesia (the child is put to sleep).
  • Pollicization is a surgery in which the index finger is taken and put in the place where there is no thumb, or there is a small thumb that does not work normally. A hand with a thumb and three fingers usually works much better than a hand with four fingers. It is also harder to see the hand difference when the child has a thumb. The index finger must work well for the surgery to be successful. Pollicization surgery has been done for many years with much success.

After surgery:

  • After surgery, your child's hand will have bandages and most likely there will be a cast placed over the bandages.
  • Depending on how much needs to be done, and how long the surgery takes, your child will most likely need to spend at least one night in the hospital.

Why choose Children's Hospital Colorado for your child’s finger/thumb hypoplasia or aplasia?

Our Hand and Upper Extremity Program team provides a comprehensive, multidisciplinary approach to the care of your child. This means you have access to leading specialists from multiple departments who work together to treat your child.

Your child's care team includes pediatric experts from orthopedic surgery, rehabilitation and physical medicine, and occupational therapy.