Winking owl sign (spine)

The (absent) pedicle sign, also called the winking owl sign, occurs on plain film when a pedicle is absent.

The term, winking owl sign, where the missing pedicle corresponds to the closed eye, the contralateral pedicle to the other open eye, and the spinous process to the beak of the animal on AP views of the thoracic or lumbar spine 1, 2.

Pathology

Aetiology

There is a wide aetiology 3, 4:

  • destroyed pedicle
  • congenital absence/hypoplasia of a pedicle
  • neurofibromatosis
  • poorly visualised
  • radiation therapy

Inspired signs
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Article Information

rID: 14693
Sections: Signs, Gamuts
Tag: spine
Synonyms or Alternate Spellings:
  • Absent pedicle sign
  • Winking owl's sign
  • Winking eye sign
  • Pedicle sign
  • The winking owl sign

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    Figure 1: winking owl
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    Case 1: absent right L4 pedicle
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    Absent pedicle
    Case 2: absent left T11 pedicle
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    Case 3: absent left L2 pedicle
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    Case 4
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    Annotated image w...
    Case 5: congenital
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    Case 6
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    Case 7: absent right L1
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