Not all wrists are "Clinical Scaphoid" 2

And here's the next.
Middle aged patient fell while at work.  Reported to have ?clinical scaphoid injury.  At review in clinic, all tenderness localised to the proximal pole of the scaphoid on the palmar wrist, with a 10p sized bruise.  Reasonable ROM and not too much pain.  What injury was missed on the Xray, how do you measure it, and what does it need?

AP view:  "Terry Thomas" sign - increased gap between scaphoid and lunate (normal 1-2 mm, abnormal 3mm)

Progressive flexion and foreshortening of the scaphoid leads to the scaphoid ring sign (NOT seen here yet.. but look below) where you see the distal pole of the scaphoid end on.

Lateral view: Increased scapholunate angle(normal 30-60º) - draw a line through the centre of the lunate and along the long axis of the scaphoid.  The Scaphoid is flexed, the lunate extended. 

These are nicely summarised at Learning radiology, where the pictures came from or Wheelless.

The patient may give a history of clicking and clunking of the wrist and on examination there is tenderness about the scapholunate interval, which lies just distal to the Lister tubercle. Provocative manoeuvres for scapholunate instability, such as the scaphoid shift/Watson’s test may be strongly positive (although they're not desperately specific).


Scapholunate instability is associated with increased scaphoid flexion and pronation with associated lunate extension (DISI – dorsal intercalated segment instability). The abnormal movement leads to a decrease in surface area contact at the radioscaphoid joint, increased concentration of load, and the development of degenerative arthritis.  If you are going to attempt to repair the intrinsic ligament acutely, you have about a 3 week window, and they'll be in a cast for 6 weeks afterwards.

Good further reading here.