x-ray wrist anatomy Flashcards
what size of joint space should uniformly be found between all carpal bones
2mm
on a lateral wrist projection, what 3 aspects should line up/be congruent
capitate, lunate and radius
what is the likely cause of a colles wrist fracture?
falling onto outstretched hand
what is the likely cause of a smiths wrist fracture
falling onto dorsal aspect of hand with flexed wrist
what is the difference between a collet and smiths fracture
colles = hand is dislocated posteriorly to wrist
smiths = hand is dislocated anteriorly to wrist
what is a Bartons fracture
intra-articular shearing fracture with subluxation at the radio-carpal joint. (describe dislocation of the distal aspect of the joint e.g anterior subluxation of radio-carpal joint)
if there is displacement of a distal radial fracture, the affected triangular fibrocartilage surrounding the carpal bones can cause what to fracture?
- avulsion of the ulnar styloid process
fractures of scaphoid are typically non-displaced and hard to see, how long are repeat radiographs requested for?
10-14 days
avulsion fractures at the distal part of scaphoid are caused by which ligament
radial collateral ligament
what is the risk of a fracture at proximal pole of scaphoid
blood supply comes from distal pole of scaphoid, so in comparison, healing at the proximal scaphoid is slower and more prone to avascular necrosis
what is the clinical method used to identify scaphoid injury
compression to anatomical snuff box
on what view can you find a triquetrial avulsion fracture
lateral wrist
- see as a dorsal fracture proximal to carpal bones
a hamate fracture is usually associated with what anatomy and how can you begin to identify it
4/5th metacarpal
- look if theres 2mm joint space
what is keinbock disease
sclerotic lunate bone
(due to avascular necrosis)
- looks denser radiographically (whiter than other carpal bones)
what is a lunate/perilunate fracture dislocation
lunate = lunate separate from capitate and radius coherence (capitate sinks proximally)
perilunate = capitate separates from lunate and radial coherence (capitate dislocated dorsally)
what is mid carpal dislocation
lunate tilts palmer but isn’t dislocated from radius AND capitate dislocated from lunate dorsally but minimally
what 6 aspects are included in the zone of vulnerability in the wrist
- radial and ulnar styloid
- capitate
- hamate (proximal pole)
- scaphoid
- triquetrium
with progression from radial to ulnar side of arch, the severity of injury increases and frequency of injury decreases
what is carpal instability and how might you identify it
- ligament rupture of carpal bones (commonly scaphoid-lunate joint)
- increase gap of joint space
- formation of triangular appearance on PA radiography
what is a galeazzi fracture-dislocation
displaced radial shaft fracture AND dislocation of distal radioulnar joint
