What Is a Limb Difference?

"Limb" is another name for the arms or legs. Limb differences are when an arm or leg is not shaped in the usual way. For example, a child's legs may be curved or one might be shorter than the other. Or, a bone in the arm may be short or missing.

A limb difference that a child is born with is called congenital. A limb difference that happens after birth is called acquired.

What Are the Signs & Symptoms of a Limb Difference?

Signs of a limb difference depend on which limb is affected and how severe the difference is. Some limb differences are so mild that you can't notice them. Others are quite noticeable and affect the way a child moves or walks.

There are many types of limb differences. For example, fibular hemimelia is when a baby is born with short and sometimes missing bones in the leg and foot. Limb length discrepancy is when one arm or leg is longer than the other. Sometimes, the knees bow out (bowlegs) or bend inward (knock knees).

A limb difference also can happen after an injury.

How Is a Limb Difference Diagnosed?

To diagnose a limb difference, orthopedic specialists (doctors and other providers who treat bone and muscle problems) talk to the family and the child, and do an exam. Tests (such as X-rays, MRIs, or CT scans) usually are done and can help the specialists decide on the best treatment.

How Is a Limb Difference Treated?

To give the best treatment, health care providers consider how severe the limb difference is, whether it makes regular activities (such as walking or writing) hard, how old the child is, and whether the difference is likely to get worse and cause other problems. Sometimes no treatment is needed.

When needed, treatment may include:

• physical therapy and/or occupational therapy
• bracing
• surgery

What Else Should I Know?

Your orthopedic team will help you find the best treatment for your child. Take time to understand exactly what will happen at each stage of the treatment plan. This way, you and your child know what to expect and can follow the plan. Correction of limb differences can require frequent visits. Parents may need to adjust work and other schedules to get the best outcome for their children.

Remember that your care team is there to answer any questions and help you get the best result for your child.