Anatomic classification of congenital limb deficiencies

The anatomic classification of congenital limb deficiencies is used to classify limb deficiencies.

The anatomic classification is proposed to systematically classify all congenital limb reduction defects and avoid terminology that can be considered imprecise or derogatory ¹.

This system is currently (c. 2024) endorsed by the World Health Organization and the Centers for Disease Control and Prevention ².

Classification

• complete absence of limb (amelia)

• intercalary defect: absence or severe hypoplasia of a section of a long bone, with normal distal structure

• terminal transverse defect: complete absence of all structures distal to a certain point of a limb

• longitudinal defect: absence or hypoplasia of a bone parallel to the axis of a limb

  • preaxial: affects the medial side of the limb. In the upper limb, it involves the thumb with or without the radius, 2^nd and 3^rd digits may be involved too. In the lower limb, it involves the hallux with or without the tibia, 2^nd and 3^rd toes may be involved too

  • central: affects the central part of all of the 2^nd to 4^th digits

  • postaxial: affects the lateral side of the limb. In the upper limb, it involves the 5^th digit with or without the ulna, 4^th and 3^rd digits may be involved too. In the lower limb, it involves the 5^th digit with or without the fibula, 4^th and 3^rd digits may be involved too

  • pre- and postaxial: mixed preaxial and post axial longitudinal defects

See also

• limb deficiency