Congenital Hand Differences


A congenital hand difference is an abnormality of the hand or arm that is present at the time of birth. The abnormality generally develops during the first four to eight weeks of pregnancy (the time in which the upper limbs are formed) and can impact the appearance and function of the affected limb(s). While the exact cause is often unknown, a variety of therapeutic and surgical treatment options is available for congenital hand differences depending on the child’s health, functionality and goals. Some children are able to forego treatment altogether.


  • Amniotic band syndrome (ABS) occurs when the amnion, a membrane intended to protect the child during pregnancy, breaks and allows loose membrane strands to wrap around and injure the child’s hand or arm.
  • Polydactyly is a condition in which the child is born with an extra finger (usually an extra thumb or little finger) on his or her hand.
  • Radial deficiency is a condition in which the forearm develops improperly, which causes the child’s hand to be bent inward (known as a “club hand”) or the thumb to be malformed or missing (known as “thumb hypoplasia”).
  • Syndactyly is the most common congenital hand difference and occurs when the child’s fingers cannot separate because they are webbed or fused together.
  • Transverse deficiency is a condition in which various components of the child’s arm are missing below a certain point, causing it to appear amputated.


  • Atypical appearance of the hand
  • Developmental issues that affect the child’s motor skills
  • Emotional and social issues
  • Problems performing daily self-care tasks and physical activities


  • There are no recommended prevention methods for congenital hand differences.

Risk factors

  • Genetic changes (spontaneous or hereditary)
  • Related medical conditions
  • Unknown. In most cases, healthcare providers are unable to determine an exact cause for congenital hand differences


  • Physical exam. The majority of congenital hand differences can be diagnosed by the child’s pediatrician after birth. If the condition is complex, however, the child may need to be referred to a pediatric orthopaedic specialist for additional testing.
  • Genetic testing. Undergoing genetic testing can be useful when the congenital hand difference is believed to be the result of a hereditary influence or underlying medical condition.
  • Imaging. X-rays can help determine which bones in the child’s body are impacted.
  • Testing for related medical conditions. The healthcare provider may need to perform additional tests if the congenital hand difference is associated with another underlying medical condition.


  • Physical and/or occupational therapy. Performing certain exercises can help strengthen the child’s arm and hand, as well as improve his or her range of motion and ability to perform a number of daily tasks.
  • Recreational therapy. In addition to adding some much needed play and creativity to a child’s life, recreational therapy can help a child develop his or her motor skills, self-esteem, mental health and social skills.
  • Use of prosthetics or assistive devices. Prosthetics can often be used to replace lost limbs, and assistive devices, such as braces or canes, work to make life more manageable for the child.
  • Surgery. Surgical procedures can help separate fingers that are webbed or fused together, reconstruct certain portions of the hand, replace skin removed during surgical reconstruction and remove duplicate fingers.

Follow-up care

  • Continued access to necessary physical support services, such as physical and occupational therapy, and emotional support services, such as peer support groups or a mental health professional, can be beneficial in helping children successfully overcome any of the long-term hurdles induced by a congenital hand difference.