Dislocation of os lunatum. Fractures of os scaphoideum

Question 1

lunate dislocation are categorically put into what ?

Answer 1

true lunate dislocation
lunate is forced volar or dorsal while the rest of the carpal bones stays in put

perilunate dislocation - lunate stays in position while carpus dislocation:

transcaphoid perilunate (scaphoid fractures )

perilunate

transradial-styloid

transcapitate

Question 2

what is the classification of lunate dislocation ?

Answer 2

mayfield classification

stage 1 - scapholunate dislocation

stage 2 = +lunocapitate dislocation

stage 3 = + lunotriquteral dislocation
(perilunate)

stage 4 = (no plus) lunate dislocated from lunate fossa and goes velary and associated with median nerve compression into carpal tunnel syndrome

Question 3

what are the findings in the x ray for lunate dislocation ?

Answer 3

in AP VIEW
break in gilula’s arc
(distal carpal bones and proximal carpal bones undersurface arc)

lunate and caput

Question 4

what is the treatment for lunate dislocation ?

Answer 4

closed reduction - finger traps with elbow at 90 degrees flexion
and traction down to the hand with weight for 15 minutes

and splinting

then followed by open reduction
fixation of any associated fractures
repair the scapholunate ligamnet ligament repair

Question 5

what is the complication of lunate dislocation ?

Answer 5

Transient ischemia of the lunate and AVN

Question 6

scaphoid fracture by location usually occurs wear ?

Answer 6

scaphoid waiste 65 percent

proximal third 25 percent

Question 7

what causes scaphoid fractures ?

Answer 7

fall on an outstretched hand

or axial loading on hyperextended and radially deviated wrist

Question 8

in scaphoid fracture what fracture attar’s are considered more stable ?

Answer 8

transverse considered more stable then vertical and oblique

Question 9

clinical symptoms of scaphoid fracture ?

Answer 9

tenderness in the anatomical snuffbox

Question 10

what is the treatment for scaphoid fractures ?

Answer 10

stable non displaced fractures - which are most fractures
thumb spica cast

distal waist occurring - 3 maths
midwaiste - 4 months
proximal third - 5 months

delay of immobilisation will increase the rate of nonunion

if displaced more than 1mm or proximal fracture
scaphoid fracture associated with perilunate dislocation
humpback deformity of the scaphoid

closed reduction and precutenaouse k wire fixation

or open reduction and internal fixation by herbert screws

Question 11

what needs to happen for there to be transcaphoid perilunate dislocation ?

Answer 11

fall on outstretched hand , hyperextension , ulnar diavtion and inter carpal supination - related to perilunate dislocation

Question 12

what are the complication of scaphoid fractures

Answer 12

the blood supply of the of scaphoid is from the radial artery - majority from the dorsal branch (and some distally the volar branch making the palmar arch) which is unique as it runs retrograde
AVN of proximal fragment is very common not so much in distal due to interruption of this retrograde blood flow

and also nonunion due to disruption of the blood flow
vascular bone graft from radius or medial femoral condyle

arthritis