Hand Injuries Flashcards
Bennett fx
fracture at the base of the first metacarpal
Rolando fx
comminuted Y shaped fracture at the base of the first metacarpal
Complication of a Bennett fracture?
Dorsolateral dislocation of the fracture fragment secondary to the pull of the abductor pollicus longus
What muscle causes dislocation of fracture fragments in a comminuted base of first metacarpal fx (Bennett fracture)?
Abductor pollicus longus
What is Gamekeeper’s thumb?
avulsion fracture at the base of the proximal first phalanx associated with ulnar collateral ligament disruption.
What is a stener lesion
Adductor tendon gets caught in the torn edges of the UCL
Adductor tendon caught in the torn edges of the UCL
Stener lesion
What is the most common carpal bone fracture?
schapoid
What is the potential complication of a scaphoid fracture?
proximal AVN. The blood supply runs distal to proximal so a scaphoid waist fx cuts off blood supply to the proximal pole –> AVN
What are the effects of SNAC on wrist alignment?
Capitate migrates proximally, radially, and dorsal to the lunate (DISI)
DISI = dorsal intercalated segment instability
- scapholunate angle > 60 deg
What is SLAC wrist?
SLAC= scapholunate advanced collapse
Happens from schapholunate dissociation
first joint to develop arthritic changes in SLAC wrist
radioscaphoid joint
What are the treatments for SLAC?
Wrist fusion: more strength, loss of motion
Proximal row carpectectomy: loss of strength, maintain ROM
What causes peri-lunate instability?
ligamentous injury
Carpal instability: Midcarpal instability nondissociative, dorsal type.
The intrinsic ligaments include the scapholunate interosseous ligament (SLIL), lunotriquetral interosseous ligament (LTIL), midcarpal ligaments, and distal carpal row interosseous ligaments. The intrinsic ligaments demonstrate higher yield strength than the extrinsic ligaments and often fail through avulsion at their attachment sites.
what is VISI?
Volar intercalated instability
VISI can occur because of a disruption of radiocarpal ligaments on the ulnar side of the wrist. The main ligaments involved in this instability are thought to be the ulnar half of the volar arcuate ligament 6 and the lunotriquetral ligament
Lunate dislocation and acute ulnar styloid fracture
The lunate is displaced and rotated volarly. The rest of the carpal bones are in a normal anatomic position in relation to the radius.
“pie in the sky” on frontal projection
“tipped tea cup” on lateral
Mechanism of injury: fall on outstreched hand (high energy trauma with loading of a dorsiflexed wrist)
Trans-scaphoid perilunate dislocation
These injuries involve dislocation of the carpus relative to the lunate which remains in normal alignment with the distal radius.
Around 60% of perilunate dislocations are associated with a scaphoid fracture
