Radial Dysplasia (radial club hand, radial longitudinal deficiency) Symptoms & Causes

At Boston Children's Hospital, our orthopedic and plastic surgery teams know how concerned you are that your baby has a hand deformity. It may help you to know that we’ve developed innovative surgical and non-surgical treatments for children with all degrees of severity of radial dysplasia. Learning more about this condition will help you feel more confident and in control as we treat — and work toward — healing your child.

What is radial dysplasia?

Radial dysplasia is a non-painful, rare congenital (meaning your baby was born with it) difference in which the radius bone of the forearm did not form properly. This causes the affected hand to be bent inward toward the thumb-side of the forearm, often with limited movement.

In addition to the curve of the wrist and forearm, your child may have a missing or small thumb.

What does "radial" mean?

When describing a specific side of the forearm, you may hear your child's doctor refer to the "radial side," which means the side of the arm on which the thumb lies, corresponding to the radius bone of the forearm. The doctor may also refer to the "ulnar side," which describes the side on which the little finger lies, corresponding to the ulna bone.

How common is radial dysplasia?

Radial dysplasia affects between one in 55,000 and 100,000 babies.

How will having radial dysplasia affect my child?

Functional consequences depend upon the severity of radial dysplasia. In the most severe cases, your child may have very limited range of motion at the wrist because her radius is completely absent. Other problems that cause limited function include:

•   an underdeveloped or missing thumb
•   abnormal muscles in the forearm, wrist, and hand
•   curvature and/or shortening of the ulna

In mild cases, the radius is merely slightly smaller than the ulna and there is minimal wrist deviation. This generally does not cause many problems with your child’s development or hand function.

Can radial dysplasia be associated with other conditions?

If your child is diagnosed with radial dysplasia, your doctor will check for other associated deformities or syndromes, including problems with the:

•   heart (such as Holt-Oram syndrome, also called hand-heart syndrome)
•   kidneys, spinal column and/or digestive system (such as VACTERL syndrome)
•   blood cells (such as Fanconi anemia, TAR)

Additional anomalies can occur with radial dysplasia, including:

•   bone/joint anomalies
•   muscle/tendon anomalies
•   nerve/artery anomalies

What causes radial dysplasia?

Radial dysplasia usually occurs sporadically (by chance). Doctors and scientists don’t know why radial dysplasia affects certain children.

In some children, radial dysplasia is associated with other congenital anomalies or syndromes that are known to have a genetic component. Some associated deformities or syndromes include those of the:

•   heart (such as Holt-Oram syndrome, also called hand-heart syndrome)
•   kidneys, spinal column and/or digestive system (such as VACTERL syndrome)
•   blood cells (such as Fanconi anemia)
•   thrombocytopenia-absent radius syndrome (TAR)

What are the symptoms of radial dysplasia?

Signs of radial dysplasia may include:

•   The affected arm is shorter, with curving of the forearm and stiffness of the wrist and fingers.
•   The thumb is either very small or missing.

The arrangement of muscles and nerves may be unbalanced, and some muscles and nerves may even be missing.

When to see a specialist

Your child’s doctor will know by sight that your baby’s hand has a radial dysplasia. The doctor will refer you to a hand specialist, who will guide you to a more detailed diagnosis and treatment plan.

Questions to ask your doctor

If your child is diagnosed with radial dysplasia, you may feel overwhelmed with information. It can be easy to lose track of the questions that occur to you. Lots of parents find it helpful to jot down questions as they arise—that way, when you talk to your child’s doctors, you can be sure that all of your concerns are addressed.

Some of the questions you may want to ask include:

•   What is happening to my child, and why?
•   What will x-rays reveal?
•   What actions might you take after you review my child’s x-rays? 
•   Is surgery necessary? Are there alternative therapies?
•   Will my child be OK after surgery?
•   Will my child recover full function of her hand? Will it look OK?
•   Will there be restrictions on her activities or capabilities?
•   What will be the long-term effects?
•   What can we do at home?

Radial dysplasia glossary


•   absent radius: condition in which the inner forearm bone (radius) is completely missing; occurs in Type 4
    radial dysplasia
•   The Center for Families at Children’s: dedicated to helping families find the information, services
    and resources they need to understand their child’s medical condition and take part in their care in radial dysplasia
•   congenital: present at birth
•   embryonic development: development of the fetus in the womb
•   in utero: in the womb (uterus)
•   occupational and physical therapy: services offered by trained professionals to help restore function or
    (re)teach basic life skills, like dressing oneself or grasping objects
•   orthopedics: the medical specialty concerned with diagnosing, treating, rehabilitating and preventing disorders
    and injuries to the spine, skeletal system and associated muscles, joints and ligaments
•   orthopedic surgeon, orthopedist: a physician specializing in surgical and non-surgical treatment of the spine,
    skeletal system and associated muscles, joins and ligaments
•   osteotomy: surgery that involves cutting bone
•   passive motion: motion in a body part guided by a helper, rather than by the patient
•   pollicization: surgical procedure in which a thumb is constructed from an existing index finger
•   post-operative (post-op): occurring after surgery
•   prenatal (fetal) ultrasound:ultrasound performed at several stages of pregnancy; may detect radial dysplasia
    in the fetus
•   pre-operative (pre-op): occurring before surgery
•   radial dysplasia (radial longitudinal deficiency): a deformity in which the radius bone of the forearm doesn’t
    develop properly, causing the hand to angulate toward the thumb-side of the forearm with limited movement
•   radius: forearm bone on the thumb-side
•   range of motion (ROM) exercises: physical therapy exercises designed to improve or restore flexion and
    extension of joints 
•   reconstructive surgery: surgery performed to repair and/or restore a body part to normal or as near normal
    as possible
•   sporadic: occurring without apparent genetic cause
•   thumb aplasia: complete absence of the thumb
•   thumb hypoplasia: underdevelopment of the thumb; can occur with radial dysplasia
•   ulna: bone on the  little finger side of the forearm 
•   x-raysa diagnostic test that uses invisible ionizing radiation to produce images of internal tissues, bones, and
    organs onto film