Classification

Central defects of the hand can be considered in terms of typical or atypical defects. In 1992, the International Federation of Societies for Surgery of the Hand determined that cleft hand should refer to typical forms whereas atypical forms were part of the spectrum of symbrachydactyly. This was an attempt to amalgamate clinical features that were described in classification systems such as that of Sandzen(1; see submenu). The features of typical and aypical cleft hands can be broadly described as:

• typical cleft hand:
  • tends to be inherited, often familial inheritance
  • often bilateral and can involve feet
  • not associated with Poland's syndrome
  • associated with cleft lip and palate
  • anatomically:
    • V-shaped deformity
    • commonly middle or index ray deficient
    • syndactyly common
  • ring finger may have three digital arteries
  • dual tendons to ring finger common
  • hypertrophy of bones adjacent to cleft
• atypical cleft hand:
  • tends to be unilateral
  • not inherited
  • this group are now considered to be a variant of symbrachydactyly; can be considered as an intercalary or isolated transverse absence of the fingers
  • anatomically:
    • absent or hypoplastic index and middle fingers giving a U-shaped defect
    • digits replaced by poorly functioning, short nubbins with nail tissue remaining
    • vestigial arterial supply to central digits
    • skeletal hypoplasia

As described in the submenu, other classification systems describe central hand defects in terms of anatomical or functional deficits.

Ref: (1) Sandzen SC (1985). Hand Clin 1: 483-498.