polydactyly

Conversion of
a DICOM-format X-ray from a patient of en:User:Drgnu23, a ten year old male. This is the patient"s left hand, posterior-anterior projection. Identifying tags and such have been stripped. The image is his, released under the GFDL. The image was subsequently altered by en:user:Grendelkhan, en:user: Raul654, and en:user:Solipsist.
Wikipedia • CC-BY-SA-3.0
Weitgehend
harmonische Hexadaktylie des Fußes. Die 2. Zehe zeigt Kriterien einer Großzehe (nur Grund- und Endphalanx, verdicktes Metatarsaleköpfchen) sowie Kriterien der anderen Zehen (Form der Grundphalanx, nur minimale Sesambeine am Metatarsaleköpfchen). Vermehrter Interphalangealer Winkel zwischen 1 und 2. Kantenbetonte Bildversion.
Wikipedia • CC BY-SA 3.0
Weitgehend
harmonische Hexadaktylie des Fußes. Die 2. Zehe zeigt Kriterien einer Großzehe (nur Grund- und Endphalanx, verdicktes Metatarsaleköpfchen) sowie Kriterien der anderen Zehen (Form der Grundphalanx, nur minimale Sesambeine am Metatarsaleköpfchen). Vermehrter Interphalangealer Winkel zwischen 1 und 2. Kantenbetonte Bildversion.
Wikipedia • CC BY-SA 3.0
Conversion of
a DICOM-format X-ray from a patient of en:User:Drgnu23, a ten year old male. This is the patient"s right hand, anterior-posterior view. Identifying tags and such have been stripped. The image is his, released under the GFDL. The image was subsequently altered by en:user:Grendelkhan, en:user: Raul654, and en:user:Solipsist.
Wikipedia • CC-BY-SA-3.0
Newborn with
short stature. AP radiograph of the hand shows polydactyly with fusion of the fifth and sixth metacarpals. The middle phalanges are short and broad and the distal phalanges are hypoplastic.The diagnosis was chondroectodermal dysplasia.
pediatricimaging.org • CC-by-nc-sa 4.0
Extending the
spectrum of Ellis van Creveld syndrome: a large family with a mild mutation in the EVCgene. Radiographs of patient IV-9. A) Coned epiphysis of the left second middle phalanx and prominent styloid process of the ulna B) Irregular notched tip of the distal phalanx of the hallux C) Bowing of the right humerus D) Fusion of the right proximal tibia and fibula.
bmcmedgenet.biomedcentral.com • CC-by-2.0
Extending the
spectrum of Ellis van Creveld syndrome: a large family with a mild mutation in the EVCgene. Radiographs of patient V-8. A) Residual appearance of postaxial polydactyly of the hand B) Abnormal appearance of some of the middle and distal phalanges of toes C) Mild lateral bowing of the humerus.
bmcmedgenet.biomedcentral.com • CC-by-2.0
Hexadaktylie
am linken Fuß beim Säugling
Wikipedia • CC BY-SA 3.0
Radiopaedia • CC-by-nc-sa 3.0 • de

Polydactyly (less commonly called hyperdactyly) refers to the situation where there are more than the usual number of digits (five) in a hand or foot. It can be broadly classified as:

Epidemiology

Estimated incidence is different for pre and postaxial polydactyly :

  • postaxial: ~1 in 3000
  • preaxial: ~1 in 7000

Central polydactyly is the rarest encountered.

In addition, there may be a greater prevalence in individuals of African descent (particularly for postaxial polydactyly) .

Pathology

Associations

A large proportion of polydactyly is isolated although they can be associated with an immense amount of anomalies which include:

Significance

If it is an isolated anomaly it is incidental and not of concern but if associated with another anomaly it then carries a vastly variable prognosis dependent on the rest of the syndrome.

Radiographic features

Other than describing polydactyly based on the position of the accessory digit, it can also be described by the number of total digits e.g. hexadactyly (six digits), or even, heptadactyly (seven digits). Indeed the presence of seven individual digits is exceedingly rare but has been reported twice .

Whilst radiology has little role in the diagnosis of polydactyly it is important in two ways:

  • assessment of the remainder of the skeleton (if appropriate) for other skeletal anomalies, and as such aiding in the diagnosis on an underlying syndrome (which in turn may point to additional unsuspected anomalies, and allow for genetic counseling etc.)
  • assess the local anatomy to aid in surgical planning. Of particular importance is the anatomy of the 'normal' digits and the relationship of the extra digit to the adjacent bones and joints.

    • History and etymology

    The term "polydactyly" is derived from the Greek words "πολύς - polus" (many) and "δάκτυλος - daktulos" (finger).

    Siehe auch:
    und weiter:
    Assoziationen und Differentialdiagnosen zu Hexadaktylie:
    Meckel-Syndrom
     
    www.eurorad.org • CC by-nc-sa-4.0
    Ellis-van-Creveld-Syndrom
     
    Wikipedia • CC BY-SA 4.0
    Skelettdysplasie
     
    Wikipedia • CC BY 2.0
    macrodystrophia
    lipomatosa
    ijponline.biomedcentral.com • CC-by-2.0
    asphyxierende
    Thoraxdysplasie (Jeune-Syndrom)
    Wikipedia • CC BY-SA 3.0
    Syndaktylie
     
    Wikipedia • CC BY-SA 4.0
    Fetales
    Valproat-Syndrom
    jmedicalcasereports.biomedcentral.com • CC-by-4.0
    Lhermitte-Duclos-Syndrom
     
    www.eurorad.org • CC by-nc-sa-4.0
    angeborene
    Handfehlbildungen
    Wikipedia • CC-BY-SA-3.0
    chondroectodermal
    dysplasia
    pediatricimaging.org • CC-by-nc-sa 4.0
    Kurzripp-Polydaktylie-Syndrome
     
    bmcmedgenet.biomedcentral.com • CC-by-2.0