Syndactyly (plural: syndactylies) refers to a congenital fusion of two or more digits. It may be confined to soft tissue (soft tissue syndactyly/simple syndactyly) or may involve bone (bony syndactyly/complex syndactyly).

The overall estimated incidence is at ~1 per 2,500 to 5,000 live births 6,8. There may be a greater male predilection.

Syndactyly can occur as an isolated phenomenon or can be associated with numerous other entities. Isolated cases can be either sporadic or familial.

  • triploidy: tend to affect the 3rd and 4th digits of the hands

There is a very wide spectrum of syndactyly ranging from partial to complete.

Overall, the 2nd and 3rd digits tend to be most frequently associated 6. May involve the toes more than fingers.

Postnatally the type and degree of bony syndactyly can be easily diagnosed on plain film.

Often difficult to diagnose on ultrasound (especially with soft tissue syndactyly). The diagnosis may be suggested if the digits appear to constantly move together 7. The fingers may appear constantly deformed with complex syndactyly 6.

The overall prognosis can be extremely variable depending on the presence of other associated anomalies.

The term syndactyly is derived from the Greek words 'syn' meaning together and 'daktulos' meaning fingers.

Article information

rID: 13659
Section: Gamuts
Synonyms or Alternate Spellings:
  • Syndactylies

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Cases and figures

  • Figure 1: clinical photograph
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  • Figure 2
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  • Case 1
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  • Syndactyly with e...
    Case 2: with Apert syndrome
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  • Case 2: with Apert syndrome
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  • Case 4: with Fraser syndrome
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  • Case 5: simple syndactyly
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  • Case 6
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