Terry-Thomas Sign


Terry-Thomas Sign: increased distance between the scaphoid and the lunate (scapholunate space) on AP XR of the wrist associated with scapholunate dissociation. Frankel in 1977, likened the widening of the scapholunate interval to the ‘upper central dental diastema‘ of British comedian Terry-Thomas

Scapholunate dissociation is associated with scapholunate ligament disruption; scaphoid subluxation, rotation and potential carpus instability

The scapholunate interval (measured at the midpoint of the adjacent parallel articular contours of the scaphoid and lunate bones) should be <2mm and scapholunate dissociation (Terry-Thomas sign) most commonly described for intervals >4mm

With scapholunate dissociation, the scaphoid often rotates to a more transverse position increasing the scapholunate angle to more than 60° and if rotated to be viewed end-on the ‘signet-ring sign‘ occurs

Terry-Thomas sign scapholunate and diastema
Terry-Thomas sign

History of the Terry-Thomas Sign

1977 – Victor H Frankel, MD proposed and sought permission from the actor Terry-Thomas that his name and physiognomy be used eponymously

The application of anthropomorphic similes can aid in the recognition of conditions that are difficult to diagnose and easily overlooked. Dental diastema (the classic Terry-Thomas dental pattern) is a useful anthropomorphic sign for detecting rotatory luxation of the navicular (scaphoid).

Frankel VH, 1978

Associated Persons

Alternative names
  • David Letterman sign
  • Scapholunate dissociation
  • Rotary subluxation of the scaphoid
  • Rotational subluxation of the navicular


Dr. Frankel graciously obtained the actor’s permission before naming a pathological entity after him. Although first eponymised in 1977, by Victor H Frankel (1977;129:321-2) – this reference had numerous errors and was reprinted with correction in 1978 (1978;135:311-2)

The application of anthropomorphic similes supplies us with diagnostic clues and triggers that simplify the complicated and clarify the opaque

Frankel VH, 1978

Alternate Carpal bone nomenclature

Bones of the carpus have had many names over the centuries. Frankel described the ‘rotational subluxation of the navicular, resulting in a gap between the navicular and lunate with similar appearance to the dental diastema of Terry-Thomas‘. In the same paper Frankel described the mnemonic for bones of the carpus as ‘Never Lower Tillie’s Pants, Grandma May Come Home.‘ – this may appear confusing…until modern nomenclature is applied

  • N = Navicular (now scaphoid); L = lunate; T = triquetrum; P = pisiform
  • G = Greater multangular (now trapezium); L = Lesser multangular (now trapezoid); C = cueiform; H = hamate


Original articles

Review articles



the names behind the name

BA MA (Oxon) MBChB (Edin) FACEM FFSEM. Emergency physician, Sir Charles Gairdner Hospital.  Passion for rugby; medical history; medical education; and asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books | Twitter |

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