Radial hemimelia is an underdevelopment of the upper limb caused by the partial or complete absence of the radius bone. A person with this birth defect appears to have had their forearm amputated. What are the causes and symptoms of radial hemimelia. How is the treatment going?

Radial hemimeliais acongenital defectcharacterized by the partial or complete absence of a radius bone (one of the two forearm bones), which means that the hands are close to the elbows.

The frequency of the defect is estimated at 1: 30,000 - 1: 100,000 births. In 38-66 percent. occurs on both sides.

Congenital lack of a radius bone may be an isolated (independent) defect, but often (25-33%) is one of the components of congenital malformations, such as Holt-Oram syndrome, VACTERL association (combination of several congenital malformations) or TAR syndrome (radial bone aplasia and thrombocytopenia syndrome). It can also coexist with other congenital abnormalities such as, for example, Fanconi anemia, digital hyperplasia or Sprengel's disease.

Radial hemimelia - causes and risk factors

The defect may be the result of a spontaneous genetic mutation or an inherited one.

There are also known risk factors for the development of radial hemimelia (teratogenic factors, i.e. factors causing fetal defects). They include:

  • x-rays;
  • viral infections during pregnancy;
  • drugs - fetal exposure to thalidomide (in the 1960s it was a drug intended to prevent morning sickness in pregnant women) in the first trimester of pregnancy is the best known factor that can lead to congenital lack of radius;

Radial hemimelia - types and symptoms of congenital lack of radius

Type 1 - shortening of the distal radius

The distal epiphysis of the radius is present but its appearance is delayed. In addition, there is a slight radial deviation of the wrist.

Each type of congenital lack of a radius has a thumb underdevelopment of varying severity.

Type 2 - underdevelopment of the radial bone

Both are preservedepiphysis of the radius bone (proximal and distal), but their growth is abnormal.

Type 3 - partial lack of radius

The radius is partially absent. The most common missing part is 1/3 to 2/3 of the distal radius. The ulna is thickened, shortened and radially folded, and the wrist is unsupported.

Type 4 - complete absence of radius

This is the most common type of congenital radius deficiency. The hand is unsupported and usually severely displaced radially.

Radial hemimelia - treatment

Surgical treatment is required to straighten and stretch the wrist and forearm.

There are several operation methods. One of them is the centralization of the wrist. Another technique is radialization, the aim of which is to move the wrist radially. In both cases, Kirschner wires or Steinmann rods (nails) are used for stabilization.

The next stage of treatment is an osteotomy (cutting) of the ulna. It is also necessary to reconstruct the underdeveloped thumb.

Category:

Genetic diseases