Wrist

Question 1

PA wrist appearance

- (carpal joints?)

Answer 1

carpal bones are arranged in two rows, with unifrom joint spaces - 1-2mm wide
- abnormally wide joint spaces indicate an injury

Question 2

Lateral Wrist Appearance

• (appearance of radius?)
• (cup, saucer apple?)
• (radial tilt?)

Answer 2

• dorsal aspect of the radius is competely smooth
• distal radius, lunate and capitate sit in a straight line (cup, saucer, apple)
• articular surface of the radius has a PALMAR TILT (2-20deg)
• if palmar tilt is not present, may be a impacted #

Question 3

NAME THE PATHOLOGY
# distal radius and ulna, posterior displacement of distal fragment

Answer 3

Colles #

Question 4

NAME THE PATHOLOGY:
# distal radius and ulna, anterior displacement of distal fragment

Answer 4

Smith’s #

Question 5

Describe a greenstick #

Answer 5

• in children

- bending of bone, incomplete fracture, only one cortex is fractured

Question 6

Describe a buckle/torus #

Answer 6

• bulging in cortex
• compression of bone
• not a complete #

Question 7

describe a Barton fracture

Answer 7

• shearing fracture involving the dorsal aspect of the distal radius through it’s articular surface
• volar Barton’s # = shearing fracture involving the volar/palmar aspect of the distal radius through its articular surface

Question 8

Scaphoid

• (risks?)
• (image appears normal?)

Answer 8

# across waist can risk blood supply to the proximal fragment
- risks malunion, non union and avascular necrosis

• if images appear normal, patient will be imaged again in roghly 10 days to see if there is ossification

Question 9

Triquetral #

Answer 9

small fragment lying posterior to PROXIMAL row of carpals on a lateral image suggests there may be a triquetral #

Question 10

NAME THE PATHOLOGY:
# of the radial shaft with angulation and dislocation of the radio-ulnar joint

Answer 10

Galeazzi fracture-dislocation

Question 11

Lunate Dislocation

Answer 11

• lunate dislocates anteriorly
• the radius and capitate remain in a straight line
• on a PA image, a dislocated lunate looks like a triangle

Question 12

Perilunate dislocation

Answer 12

• often associated with a scaphoid #
• the whole carpus (apart from the lunate) is displaced posteriorly
• the lunate and radius remain in line, the capitate lies posteriorly

Question 13

Carpal Subluxation

• (joint spaces?)
• (signs?)

Answer 13

• intercarpal joint spaces are no more than 2mm, widening is a sign of subluxation
• scapholunate subluxation: gap between scaphoid and lunate known as terry thomas or madonna signe
  - suggests damage to scapholunate ligaments

Question 14

zone of vulnerability (carpals)

Answer 14

• an arc passes from radial styloid process, the scaphoid ,proximal aspects of capitate and hamate and the ulanr styloid prcess
• if there is an abnormality somewhere in this arc, look at the rest of the arc for #

Question 15

PA Wrist Positioning

Answer 15

• affected arm is abducted and elbow flexed 90 deg. Palm of hand touching detector
• centre midway between radial and ulnar styloid processes, midcarpal region
• collimate to include 1/2 metacarpal bones, distal 1/4 of the radius and ulna
• 55kVp 2mAs

Question 16

Lateral Wrist Positioning

Answer 16

• affected arm is abducted and elbow felxed 90 deg. Ulanr aspect of hand in contact with detector
• shoulder, elbow and wrist should be in the same plane
• radial and ulnar styloid processed should be superimposed
• centre midcarpal region
• collimate to include 1/2 metacarpals, distal 1/4 radius and ulna, dorsal and palmar skin margins.
  57kVP 3mAs