Case Of The Month

Presentation: 

Fell on outstretched hand.  Tender at the base of the thumb.

Investigations: 

 A series of  xrays were taken, showing no abnormality

MRI scanning was performed.  This revealed a typical scaphoid fracture. 

Left image:  Plain xray.  Normal appearances

Middle Image:  MRI (T1 scan) reveals an undisplaced fracture through the waist of scaphoid (arrow)

Right Image:  MRI  (T2 with fat suppression) shows oedema in the region of fracture (arrow)

Diagnosis:

Occult fracture of the scaphoid

Discussion:

 Protocols for the management of a patient with a suspected scaphoid fracture where the xrays appear normal traditionally involve applying a cast and repeating the xray in two weeks. This can results in time off work, loss of income, ACC and employer costs, patient inconvenience and medicolegal consequences. Worryingly, scaphoid fractures can still be present despite a normal follow up xray.

 MRI allows accurate and rapid diagnosis of scaphoid fractures. If the scan is normal, a cast is not required, allowing an early return to normal activities.  MRI can also show unsuspected occult fractures of the distal forearm and wrist.

 MR is ideally used to confirm or exclude an occult fracture at initial presentation, but may also be used after an indeterminate follow up radiograph.