scaphoid fracture

Question 1

mechanism of injury of scaphoid fracture

Answer 1

• fall onto outstretched hand (FOOSH)
• contact sports

-> axial compression of scaphoid, with wrist hyperextended and radially deviated

Question 2

blood supply of scaphoid bone

Answer 2

80% blood derived from dorsal carpal branch of radial artery - retrograde
interruption -> avascular necrosis in prox injuries

Question 3

signs and sx of scaphoid injury

Answer 3

• pain along radial aspect of wrist, at base of thumb
• loss if grip/pinch strength
• max tenderness - anatomical snuff box
• wrist joint effusion - unlikely in hyperacute injuries (less than 4hrs old), delayed presentation (more 4 days)
• pain on telescoping of thumb
• tenderness of scaphoid tubercle on volar aspect of wrist
• pain on ulnar deviation

Question 4

ix for scaphoid fracture

Answer 4

plain XR
* AP and lateral
* ‘Scaphoid views’: posterioranterior (PA), lateral, oblique (with wrist pronated at 45º) and Ziter view (PA view with the wrist in ulnar deviation and beam angulated at 20º)

CT in ongoing clinical suspicion / plan mx / assess recovery

MRI definite ix - first line but not common prctice

Question 5

mx of scaphoid fracture

Answer 5

1. immobilisation with a Futuro splint or standard below-elbow backslab
2. refer to ortho - further imaging in 7-10 ays when initial XR inconclusive

undisplaced scaphoid waist
* cast 6-8wks
* sports people may benefit from early surgical intervention

displaced
* surgical fixation

prox scaphoid fractures
* surgical fixation

Question 6

complications of scaphoid fracture

Answer 6

non-union -> pain and early OA
avascular necrosis