Module 2: MSK Flashcards
stress fracture is
abnormal stress on normal bone
insufficiency fracture is ..
normal stress on abnormal bone
bones heal in how many weeks
6-8
Most often scaphoid fracture
waist 70%
thenproximal 20%
then distal 10%
first sign of AVN for scahpod fracutre
sclerosis
why does sclerosis signify AVN in scaphoid
dead bone can’t turnover
location of fracture most at risk of aVN in scaphoid
proximal
Scaphoid fracture on MRI look for what
Dark on T1
What is a SLAC wrist
complication of trauma
Scapho-lunate advanced collapse
injury to SL ligament
what is SNAC wrist
a potential complication of trauma as well
Scaphoid non-union advanced collapse
happens with injury to the scaphoid
which way does the scahpoid want to be rotating
what holds it back
flexion
SL ligament holds it back
if SL breaks what happens to the capitate?
the scaphoid radial distance narrows
the capitate moves proximally.
how can you treat a SLAC wrist?
wrist fusion - max strength loss of motion
proximal row carpectomy - max rom, lose strength
describe a perilunate dislocation
capitate moved off the back (sits perilunate)
describe a midcarpal dislocation
lunate is dislocated anteriorly and capitate posterily
(all moved from the mid)
describe a lunate dislocation
lunate rotate and dislocated anteriorly.
Normal Scaphlunate distance
3mm
the lunate wants to move in which direction ?
rock posteriorly
what does DISI stand for
dorsal intercalated segmental instability
VISI stands for
volar intercalated segmental instability
What happens in DISI ?
rocking dorsally of the lunate
happens due to an injury of the SL ligament. (therefore a radial sided injury)
What happens in VISI?
very rare
ulnar sided injury will damage the lunotriquetral ligament. Lunate is no longer pinned.
Lunate will tilt volar direcitons.
what is the normal scaphoid lunate angle?
30 - 60 degrees
DISI vs VISI angles ?
DISI - opens the angle- greater than 60
VISI - closes into a V - less than 30