Radial Dysplasia

What is radial dysplasia?

Radial dysplasia, also called radial longitudinal deficiency, occurs when the radius bone in the forearm does not develop correctly. It is congenital, meaning it's a condition a baby is born with.

In babies with radial dysplasia, the radius bone is too short or is missing completely. This can make the arm and hand turn in towards the thumb side of the hand. In severe cases, the baby may also have a small or missing thumb. The condition can occur in one or both arms.

There are four types of radial dysplasia, ranging from mild to severe.

• Type 1 is the mildest form. In this type, the radius may just a bit shorter than normal, causing a slightly turned wrist.
• In type 2, the radius bone is much shorter than normal. Children with this type may also have thumb that is smaller than normal.
• In type 3, the radius bone is very underdeveloped, and most of it may be missing. Many children with this type also have a small or missing thumb.
• In type 4, the most severe form, the radius bone is missing completely. Most children with this type also have a missing thumb and may have other missing fingers.

What are the signs and symptoms of radial dysplasia?

The symptoms of radial dysplasia are usually visible at birth. They can vary depending on the type your child has. Symptoms may include:

• A turned-in wrist
• A shortened forearm
• A missing thumb
• Problems using the hand or fingers

What causes radial dysplasia?

Radial dysplasia occurs while a baby is developing during pregnancy. Experts do not know what causes the condition, although sometimes it runs in families. In some cases, it may be part of a larger syndrome, in which a baby has other medical conditions.

How is radial dysplasia treated?

Your child's treatment for radial dysplasia will depend on which type they have and their individual symptoms. Your care team at Arkansas Children's is experienced in treating all types of radial dysplasia and will work with you to create the best treatment plan for your child.

Treatments may include:

• Exercises to help improve your child’s range of motion.
• Splinting or casting to stretch the wrist and arm.
• Surgery to improve function in the arm, wrist or hand. Some children with severe radial dysplasia may need several surgeries over a period of years.