Wrist & Forearm Trauma

Question 1

name the 4 types of trauma associated with the hand

Answer 1

• scaphoid fractures
• colles fracture
• smith’s fracture
• wrist dislocation

Question 2

describe a scaphoid fracture

Answer 2

deformity of scaphoid where it fractures into 2 or more fragments
(70-80% of carpal bone fractures occur at the scaphoid as the force is transmitted to it)

Question 3

MOI for a scaphoid fracture

Answer 3

hyperextension of wrist with compression

Question 4

describe and name a serious concern with scaphoid fractures

Answer 4

avascular necrosis - prevents blood getting to the proximal
fracture fragment

Question 5

describe the radiographic appearance of scaphoid fractures

Answer 5

• lucent line across the waist of
  the scaphoid
• a ‘fat pad’ sign indicates a fracture is present even if fracture line not evident
• fat pad is a small triangular collection of fat alongside the scaphoid

Question 6

describe the treatment for scaphoid fractures

Answer 6

• stable fractures need immobilisation in thumb spica
• up to 5 months if the proximal portion
• unstable fractures need surgical fixation, bone grafting and immobilisation

Question 7

describe a colles fracture

Answer 7

an extra-articular transverse fracture of the distal radius, where the distal fragment is displaced posteriorly

Question 8

MOI for a colles fracture

Answer 8

• fall on an outstretched hand
• forearm is pronated and in dorsi-flexion, which is why fracture fragment moves posteriorly on impact

Question 9

describe the radiographic appearance of colles fracture

Answer 9

• PA shows impaction at the fracture site
• lateral shows posterior displacement of the distal fragment
• pronator quadratus fat pad is visible
  indicating underlying haematoma around fracture site

Question 10

describe the treatment for a stable colles fracture

Answer 10

closed reduction and immobilisation in cast

Question 11

describe the treatment for an unstable colles fracture

Answer 11

Open reduction internal fixation with either K wires or pin and plate fixator

Question 12

describe the prognosis for a colles fracture

Answer 12

prognosis is good however complications:
- osteoarthritis
- mal-union resembling dinner fork deformity
- carpal tunnel issues
- associated nerve palsy

Question 13

describe smiths fracture

Answer 13

an extra-articular transverse fracture of the distal radius, where the distal fragment is displaced anteriorly

Question 14

MOI for a smiths fracture

Answer 14

a fall onto flexed wrist or direct blow to dorsal aspect of the hand, where fragment moves anteriorly on impact

Question 15

describe the radiographic appearance of a smiths fracture

Answer 15

• PA view shows impaction at the fracture site
• lateral view shows anterior displacement of distal fragment

Question 16

describe treatment for a stable smiths fracture

Answer 16

closed reduction and immobilisation in a cast

Question 17

describe treatment for an unstable smiths fracture

Answer 17

open reduction internal fixation with pin and plate fixator

Question 18

describe the prognosis for a smiths fracture

Answer 18

prognosis is good possible complications:
- osteoarthritis
- mal-union with ‘volar’ displacement
- ‘garden spade’ deformity leading to carpal tunnel issues
- long term ligament damage

Question 19

describe a wrist dislocation

Answer 19

overlapping of the carpal bones and the joint spaces to be reduced or widened - usually the lunate moves out of anatomical position

Question 20

MOI of a lunate dislocation

Answer 20

fall onto outstretched hand in dorsi-flexion

Question 21

describe the radiographic appearance of a lunate dislocation

Answer 21

the lunate is tipped anteriorly ‘spilled tea cup’ sign and the carpal bones overlap

Question 22

describe the treatment of a lunate dislocation

Answer 22

open reduction internal fixation and K wires or screws and cast 2/3 months

Question 23

describe the prognosis for a lunate dislocation

Answer 23

• high risk of nerve palsy
• degenerative arthritis
• wrist instability due to long term ligamentous damage
• essential repair needed to minimise this