Radial longitudinal deficiency is a rare condition that affects the forearm. It is a congenital condition, meaning your baby was born with it, and can affect one or both arms. It is sometimes called radial club hand, radial dysplasia, or radius deficiency.
There are two bones in your baby’s forearm: the ulna, on the outer side of the arm, and the radius, on the inner side. Radial longitudinal deficiency occurs when the radius does not form properly. This causes the wrist to bend toward the thumb side of the forearm.
Radial longitudinal deficiency also affects the soft tissues and flesh of the forearm. The arrangement of muscles and nerves may be unbalanced, and some muscles and nerves may be missing.
If your child has a mild form of radial longitudinal deficiency, the condition will probably not cause problems with their development or hand movement.
If your child has a severe form, they may have problems moving their hand, fingers, and elbow. Their entire arm will be shorter, with a curved forearm and stiff elbow and fingers. They may also have a small or missing thumb.

Radial longitudinal deficiency usually occurs by chance, although for some people it can also run in the family. Doctors and scientists do not know why some children are born with this condition. There are several theories, including compression of the uterus and blood vessel injury. None of these theories have been proven, however.
There are no known links between this condition and the mother’s lifestyle or anything the mother may do during pregnancy.
Radial longitudinal deficiency is associated with several congenital syndromes, including those affecting the heart, digestive system, and kidneys. It has also been linked to some chromosomal abnormalities, including Down syndrome and Trisomy 18 and 13.
Radial longitudinal deficiency is sometimes picked up on a prenatal ultrasound, but the condition cannot be treated until after your baby is born.
If your child’s condition is detected after birth, a doctor will examine their forearm and take an X-ray. Your child’s doctor will check for other differences or syndromes that are associated with radius deficiency. Additional tests could include blood tests and ultrasounds of the kidneys and possibly the heart.
Your child’s treatment will depend on how severely their arm and hand are affected. The goals of treatment are to:
When your child is an infant, their doctor will talk to you about how to perform gentle stretching exercises for your child’s wrist and elbow to help improve the range of motion in those joints.
Even if your child will eventually need surgery, range-of-motion exercises are extremely important. Any improvement in range of motion achieved through exercise will make surgery more effective and possibly less complex. Your baby will probably need to wear a splint at night throughout infancy and during times when they grow quickly.
If your child’s condition is severe, they may wear a cast or splint to gradually stretch the soft tissues in their forearm.
Your child’s doctor must weigh the decision to perform surgery against any other medical conditions your child may have, as well as the overall function of their arm.
If your baby has severe radial longitudinal deficiency, they may need surgery after a period of stretching and splinting. Surgery is also an option if problems with the thumb interfere with your child’s use of their hand.
Each part of the arm is treated during separate surgeries that may take place over months or years, typically starting when your child is about 1. Below are surgeries your child may need to treat different parts of their arm and hand. The number and timing of these surgeries will depend on your child and their condition:
Osteotomy involves cutting a bone into wedges and reshaping it. In cases of radial longitudinal deficiency, the surgeon will perform an osteotomy on the forearm bones in order to straighten them. The wedges of bone are held in place by pins while the bone heals. These pins are removed once the bone has grown strong in its new position.
Many children with radial longitudinal deficiency need surgery to reconstruct their thumb. If the thumb is only mildly underdeveloped, a surgical procedure called an opponensplasty can strengthen the thumb muscles. When the thumb is more significantly underdeveloped or missing, the surgeon may perform a pollicization to reposition the index finger as a thumb.
Elbow surgery is rarely needed. Some children who have difficulty bending their elbow will undergo a procedure to release tight soft tissues at the back of the elbow that make the elbow stiff. This can be done separately or in combination with procedures to correct the wrist and thumb.
Your child’s long-term outlook depends on the severity of their condition and whether they have any associated conditions.
If your child has a mild case of radial longitudinal deficiency, they will need physical therapy as they grow in order to keep their arm and wrist aligned and strong. They may have minor problems moving and using their arm.
If your child has more severe radial longitudinal deficiency, their arm will have limited range of motion, strength, and movement, but there are many possible ways to adapt. Ongoing physical and occupational therapy are often helpful to help your child get the most use of their arm possible as they grow and develop.
The Orthopedics and Sports Medicine Department’s Hand and Orthopedic Upper Extremity Program and our the Department of Plastic and Oral Surgery’s Hand and Reconstructive Microsurgery Program have treated thousands of babies and children with radial longitudinal deficiency and other hand problems. We are experienced treating conditions that range from routine to highly complex and can provide your child with expert diagnosis, treatment, and care. We also offer the benefits of some of the most advanced clinical and scientific research in the world.
Our Orthopedics and Sports Medicine Department is nationally known as the preeminent center for the care of children and young adults with a wide range of developmental, congenital, neuromuscular, sports-related, traumatic, and post-traumatic problems of the musculoskeletal system.
Our Department of Plastic and Oral Surgery is one of the largest and most experienced pediatric plastic and oral surgery centers anywhere in the world. We provide comprehensive care and treatment for a wide variety of congenital and acquired conditions, including hand deformities.