Terry Thomas sign

Dr Ian Bickle and Dr Andrew Dixon et al.

The Terry Thomas sign refers to an increase in the scapholunate space on an AP radiograph of the wrist (or coronal CT). The increased distance indicates scapholunate dissociation (often with rotary subluxation of the scaphoid) due to ligamentous injury. There is no consensus as to what measurement constitutes widening, but a cut-off of 3 or 4 mm is reasonable in most cases.

History and etymology

The sign is named after the well-known British comic Terry Thomas (1911-1990) who had frontal dental diastema (a large gap between his two front teeth) 1. It may also be known as the David Letterman sign for the same reason.

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Article Information

rID: 10013
Section: Signs
Synonyms or Alternate Spellings:
  • David Letterman sign

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Cases and Figures

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    Figure 1: Terry Thomas cartoon
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    Scapholunate diss...
    Case 1: Terry Thomas sign
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    Scapholunate diss...
    Case 1: Terry Thomas sign
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    Case 2: scapholunate dislocation
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    Case 3
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    Case 4
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