radiology Radiology ( ) is the medical discipline that uses medical imaging to diagnose diseases and guide their treatment, within the bodies of humans and other animals. It began with radiography (which is why its name has a root referring to radiati ...

, the Terry-Thomas sign is a

scapholunate ligament The scapholunate ligament is a ligament of the wrist. Rupture of the scapholunate ligament causes scapholunate instability, which, if untreated, will eventually cause a predictable pattern of wrist osteoarthritis called scapholunate advanced col ...

dissociation on an

anteroposterior Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

view of the wrist. Most commonly a result of a fall on the outstretched hand ( FOOSH), the

ruptures resulting in separation of the

lunate Lunate is a crescent or moon-shaped microlith. In the specialized terminology of lithic reduction, a lunate flake is a small, crescent-shaped flake removed from a stone tool during the process of pressure flaking. In the Natufian period, a lu ...

and scaphoid bones. This burst causes the scaphoid bone to dorsally rotate. A gap of more than 3mm is

pathognomonic Pathognomonic (rare synonym ''pathognomic'') is a term, often used in medicine, that means "characteristic for a particular disease". A pathognomonic sign is a particular sign whose presence means that a particular disease is present beyond any dou ...

for scapholunate dissociation. The resulting separation between the scaphoid and lunate bones leaves a space on the x-ray that is similar to the gap comedian Terry-Thomas had between his front teeth. For newer radiology students who do not know who Terry-Thomas was, this finding might also be known as the

David Letterman David Michael Letterman (born April 12, 1947) is an American television host, comedian, writer and producer. He hosted late night television talk shows for 33 years, beginning with the February 1, 1982 debut of '' Late Night with David Letterma ...

sign.

References

External links

Entry on RadiopaediaCase study and history from PubMed
Radiologic signs {{Med-sign-stub