Wrist radiographs are ubiquitous on any night of the week in emergency departments, especially when pavements are icy!
On this page:
Systematic review
Choosing a search strategy and utilizing it consistently is a helpful method to overcome common errors seen in diagnostic radiology. The order in which you interpret the radiograph is personal preference. A recommended systematic checklist for reviewing musculoskeletal exams is soft tissue areas, cortical margins, trabecular patterns, bony alignment, joint congruency, and review areas. Review the entire radiograph, regardless of perceived difficulty. Upon identifying an abnormality, do not cease the review, put it to the side and ensure to complete the checklist
Soft tissue
Assess all soft tissue structure for any associated or incidental soft tissue signs
Bone cortex
Check each bone in turn:
- pay particular attention to the distal radius, proximal carpal row (especially the scaphoid) and the bases of the metacarpals
Bony alignment
Distal radial contour
Check the contour of the distal radius:
- AP
- the distal radial articular surface should cup the carpals
- the articular surface should get progressively more distal towards the radial styloid
- radial inclination angle should be 15-25°
- lateral
- the radial surface should be smooth
- there should be a palmar tilt to the articular surface
- volar tilt should be around 10-25°
- if these features aren't present, think distal radial fracture
Carpal arcs
Check the carpal arcs:
- the articular surfaces of the proximal and distal carpal rows should form three smooth arcs
- trace these arcs on the AP film
- the spacing between all carpal bones should be 1-2 mm
- if the arc is broken or there is a widening of a joint space, think carpal dislocation
Carpal alignment (lateral)
Check lateral alignment:
- the distal radius, lunate and capitate should be in a straight line
- if the line has been disrupted, think:
- lunate dislocation: lunate is completely dislocated
- perilunate dislocation: capitate and other carpal bones (except lunate) are dislocated
- the scapholunate angle should be between 30o and 60o in the neutral position
- capitolunate angle should be less than 30o in the neutral position
Joint congruency
Carpometacarpal articulation
Check carpometacarpal joint space:
- a 1-2 mm joint space should be seen between the carpals and metacarpals
- if the joint space is narrowed, think carpometacarpal dislocation
One of the commonest misses in trauma films of the hand and wrist is a dislocation of the 5th carpometacarpal joint which may cause significant morbidity if the diagnosis is delayed.
Common pathology
Colles fracture
- the most common distal radial fracture in any adult group
- peak incidence in elderly women
- usually, following a fall onto an outstretched hand
- dorsal angulation of the distal fracture component
- important to determine if there is intra-articular extension
- more: Colles fracture
Smith fracture
- account for less than 3% of forearm fractures
- more common in young males and elderly females
- fall onto flexed wrist or direct blowback of wrist
- classically, an extra-articular distal radius fracture with palmar angulation of distal fracture fragment
- also called the reverse Colles
- more: Smith fracture
Scaphoid fracture
- 80% of all carpal bone fractures
- usually young adults
- fall on an outstretched hand
- 80% of fractures are through the waist of the scaphoid
- if suspected, perform additional scaphoid views
- may be radiographically occult - should be followed up if pain persists
- more: scaphoid fracture
Triquetral fracture
- second most common carpal bone fracture
- hyperextension or avulsive injury
- frequently seen as dorsal chip fractures on lateral views only
- more: triquetral fracture
Perilunate dislocation
- typically occur in young adults
- following a fall on the dorsiflexed wrist
- best detected on lateral view - the lunate articulates with distal radius but capitate does not sit in lunate ‘cup’
- 60% associated with scaphoid fracture
- more: perilunate dislocation
Don't miss...
Scapholunate dissociation
- injury to the scapholunate and radiolunate ligament results in scapholunate dissociation and significant instability
- the scapholunate space is widened (> 4 mm) - the Terry Thomas sign
- more: scapholunate dissociation
Lunate dislocation
- much less common than perilunate dislocation
- commonly occur in young adults
- fall onto a dorsiflexed wrist
- more: lunate dislocation
Carpometacarpal dislocation
- rare but important injury to dominant hands of younger males
- younger male predominance
- often occur after a punch followed by a fall
- reduction of joint space on the AP
- best seen on an oblique study
- more: carpometacarpal dislocation
Unable to process the form. Check for errors and try again.