Skeletal limb abnormalities are problems in the bone structure of your arms or legs. They can affect a part of your limb or the entire limb. Usually these problems are present at birth and sometimes babies are born with abnormalities in more than one limb.

Certain diseases or injuries can disturb the normal growth of your bone structure and lead to skeletal abnormalities as well.

Congenital abnormalities

A congenital skeletal abnormality is present when you’re born. The abnormality may mean that one of your limbs is smaller or larger than normal or that you have more fingers or toes than normal. You could also be missing an entire arm or leg, or you might be missing a segment of one of your limbs or have fingers and toes that are not be completely separated from each other.

Congenital limb abnormalities are rare. These abnormalities can happen because of a chromosome problem, or in some cases, congenital limb abnormalities can result from a mother taking prescription drugs during pregnancy.

In the United States, approximately 1,500 babies are born with skeletal abnormalities in their arms and about half as many newborns have skeletal abnormalities in their legs, according to the Centers for Disease Control and Prevention.

Acquired abnormalities

An acquired abnormality is one that happens after birth. Such a condition occurs if you were born with normal limbs but experienced a bone fracture during childhood. The broken bone might grow more slowly than usual, leading to the affected arm or leg developing abnormally.

Some diseases, such as rickets and rheumatoid arthritis, can negatively affect your bone structure, leading to abnormalities in your legs or arms.

If you’re born with a skeletal limb abnormality, outward symptoms can be obvious, such as:

  • a limb that isn’t fully formed or is
    missing a component
  • one leg or arm that is shorter than the
  • legs or arms that aren’t in proportion
    with the rest of your body

In the case of acquired limb abnormalities, you might not have any external symptoms. Some common signs of an acquired limb abnormality are:

  • one leg appears to be shorter than the
    other leg
  • pain in your hip, knee, ankle, or back
  • one shoulder looks slumped in comparison
    to the other
  • unusual walking gait such as a limp,
    rotating your leg in an unusual way, or walking on your toes

Currently, the causes of congenital skeletal limb abnormalities are not fully understood. Possible risk factors include:

  • being exposed to viruses, medications,
    or chemicals before birth
  • tobacco use by the mother while pregnant
  • having other kinds of abnormalities, including
    omphalocele, a heart defect, or gastroschisis
  • congenital constriction band syndrome,
    in which bands of amniotic tissue get tangled in your arms or legs before
    your birth

Acquired limb abnormalities can be caused by childhood injury. Some of these injuries result in slower bone growth. They can also be caused by a number of diseases that affect your bone structure, including:

  • rickets, or vitamin D deficiency
  • Marfan syndrome, a connective tissue
  • Down syndrome, a genetic disorder
    involving extra chromosomes

If the abnormality is present when you’re born, it usually can be diagnosed immediately with a physical examination.

An acquired skeletal abnormality requires a fairly extensive examination. This procedure includes viewing your medical history, taking a physical exam, and measuring your limbs. X-rays, CT scans, and other types of medical imaging also can be used to view underlying bone structure and diagnose abnormalities.

There are three primary goals of treatment for congenital limb abnormalities, including:

  • encouraging development of the
    affected limb
  • improving the appearance of the
    affected limb
  • helping you adapt to day-to-day issues
    that may be caused by the abnormality

Your doctor will help you decide the best type of treatment for your specific condition.

Supportive devices

Your doctor may prescribe an artificial arm or leg, known as a prosthetic limb. It functions in place of a normal limb.

In some cases, your affected limb may be present but weakened. An orthotic brace or splint may be used to support your affected limb so it can function normally.

Occupational or physical therapy

In some cases, your doctor may recommend occupational therapy or physical therapy to help exercise and strengthen your affected limb.


Sometimes surgery is necessary to repair an abnormality in your leg’s structure. Two types of surgery are epiphysiodesis and femoral shortening. Epiphysiodesis is a carefully timed procedure to stop the normal growth of one leg so that the shorter leg can reach an equal length. Femoral shortening is a procedure where part of the femur, or thigh bone, is removed.

Limb lengthening

Your doctor might recommend elongating a short limb through a gradual process called limb lengthening. For this procedure, your doctor will cut your bone and use an external device to gradually increase the length of your leg over the course of several months to a year. This procedure can be painful and has a higher potential for complications than other treatments.

As a child with a skeletal limb abnormality, you may face a variety of physical and emotional difficulties. Your experience will depend on where the abnormality is located and how severe it is. Possible issues include:

  • problems with developing motor skills
    and other physical milestones
  • limitations in sports participation or
    other activities
  • being teased or excluded because of
    differences in your appearance
  • needing help in personal activities,
    such as eating or bathing

Ongoing medical treatment for skeletal limb abnormalities can assist you in gaining optimal functioning and independence. Many people with some type of limb deformity are able to live productive and healthy lives.

There is no certain way to prevent skeletal limb abnormalities from occurring. Instead, the focus is on early detection and treatment.

Pregnant women can decrease chances of limb abnormalities in their babies by taking a prenatal vitamin that includes folic acid. It’s also recommended that pregnant women avoid tobacco and alcohol use.