Radial Dysplasia

Radial dysplasia is underdevelopment, abnormal development, or absence of the structures on the radial side (the “thumb side”) of the forearm, wrist, and/or hand. There is a spectrum of involvement, ranging from a slightly small thumb, to complete absence of the thumb, radial wrist bones, and the radius bone itself (the bone on the “thumb side” of the forearm). In some cases, only the radius is involved. The term “radial clubhand” comes from the appearance of the hand and forearm when the radius is very short or absent: the hand is bent at 90 degrees to the forearm, resembling the appearance of a golf club. Radial dysplasia affects only one side in about 50% of cases, and the right side is twice as commonly affected as the left.

Common Questions

Does radial dysplasia cause my baby any pain?

No, typically there is no pain associated with this condition.

What are the different types of radial dysplasia?

There is a spectrum of involvement in radial dysplasia, as in many of the congenital anomalies. Radial dysplasia may involve only the forearm; the forearm, wrist, and thumb; only the thumb; or the thumb and wrist. Moreover, for each involved structure (e.g. the radius, the thumb), there is a range of involvement, from mild to severe.

Who gets radial dysplasia?

Radial dysplasia can occur in any newborn infant. There is no pattern of inheritance. This condition is rare, and occurs in approximately one in 30,000 to 1 in 100,000 newborns. Boys are affected slightly more often than girls, and Caucasians are affected more than other races.

What causes radial dysplasia?

Although there are many theories, the cause of radial dysplasia has not been determined.

What are the main issues related to radial dysplasia?

The primary issue in radial dysplasia is function of the hand and digits; appearance of the hand is also an issue, but is secondary to function. Children with an under-developed or absent thumb cannot pinch and grasp objects effectively. This is a significant limitation, because the thumb normally accounts for about 40% of total hand function. If the thumb is only mildly or moderately under-developed, the child will try to use it. However, if the thumb is severely under-developed or absent, the index finger begins to substitute for the thumb: the space between the index and middle fingers gradually widens, the index finger rotates toward the middle finger, and the child tries to pinch between the index and middle fingers.

In addition, if the forearm is short and the hand bent in the “clubhand” position, the child may have difficulty with various tasks, such as reaching for objects or getting the hand into a sleeve.

Are there other problems that occur commonly with radial dysplasia?

Yes, radial dysplasia may be associated with a number of other problems, some of them potentially very serious. Therefore, it is critical that any baby with radial dysplasia be carefully and thoroughly examined by an experienced pediatrician. Diagnostic tests such as special x-rays and ultrasounds are usually done. The commonly associated problems may be remembered by the acronym VACTERL: V for vertebral, or spine; A for anal or rectal; C for cardiac, or heart; TE for tracheo-esophageal (the trachea and esophagus); R for renal, or kidney; and L for limb. In addition, there may be serious anemias and other blood disorders.

What is the treatment for babies with radial dysplasia?

While every patient is treated individually, with treatment plans made specifically for him or her, some generalizations are possible. When the radial clubhand deformity is present, a regimen of stretching and splinting is begun with the help of a hand therapist to try to keep the wrist supple and allow the hand to be passively straightened on the forearm. In some babies, the elbow is very stiff and does not bend well; in those patients, straightening the hand would be detrimental, because the baby will actually take advantage of the bent position of the hand to reach its mouth. Many different procedures exist to achieve a better posture of the hand on the forearm. Your surgeon will work with your child to determine the best option for him/her.

The most important treatment intervention is to reconstruct a functional thumb. In cases with mild or moderate under-development of the thumb, reconstruction is done using the tissues of the small thumb and borrowing a tendon(s) from other digits on the hand. However, when the thumb is severely under-developed or absent, reconstruction is not possible. Rather, a completely new thumb is created, usually using the index finger, in an elegant operation known as pollicization. In pollicization, the index finger is moved into the thumb position and adjusted in length and posture to look and function like a thumb.

Hand therapy will be an on-going part of the treatment plan, before and after surgery.

What is done between the time my baby is born and the first surgery?

You will meet with your surgeon soon after your baby is born. In some cases, the diagnosis is made prenatally by ultrasound exam, and you may have the opportunity to meet your surgeon before your baby is born. Your surgeon will examine your baby and take xrays of the affected hand. Your baby will be examined in the clinic periodically during the months before surgery. The treatment plan and the details of the surgical procedures will be carefully explained to you by your surgeon. A hand therapy regimen, with stretching and splinting, may be started soon after birth.

What sorts of specialists will be involved in my baby’s care?

At the very least, your child will be treated by the hand surgeon, a certified hand therapist, and a pediatrician. Depending on what, if any, other abnormalities are detected, a variety of other pediatric specialists may be involved.

Will we get to know our surgeon?

Ideally, you will meet your surgeon either prenatally or soon after your baby is born. You will meet with your surgeon several times before surgery, and will get to know him quite well. Many children with radial dysplasia require multiple surgeries, and the family and surgeon often work together for quite some time.