Hands Flashcards
Principles of Tendon Transfer
Single
Supple
Sacrificable
Sufficient strength
Synergistic action
Short excursion
Single Line of Pull
Performing a single action
Passing over a stable joint
Common Tendon Transfers - Radial nerve palsy (1/3)
Deficiency:
Wrist extension
Lost:
ECRL/ECRB
Transfer:
Pronator Teres (median n) to ECRB
Common Tendon Transfers - Radial nerve palsy (2/3)
Deficiency:
Finger extension
Lost:
EDC, EIP, EDM
Transfer:
FCR & FCU to EDC 2-5
FDS 3 or Palmaris Longus to EPL & EIP
FDS 4 to EDC 3-5
Common Tendon Transfers - Radial nerve palsy (3/3)
Deficiency:
Thumb extension
Lost:
EPL
Transfer:
Palmaris longus to EPL
FDS 3 to radial lateral band
ECRL to lateral band
Perilunate Dislocation
Failure of perilunate ligaments with resultant loss of lunate congruency through greater arc. Lunate stays in place and carpus dislocates.
Lunate dislocation
Failure of perilunate ligaments (Mayfield Stage IV - scapholunate, lunocapitate, lunotriquetral and dorsal radiocarpal ligaments) such that lunate dislocates into Space of Poivier/carpal tunnel but carpus remains aligned with radius.
Classification of Perilunate Dislocations
Mayfield - Stages I to IV
Stage I - Scapholunate ligament injury
Stage II - Stage I + Lunocapitate disruption
Stage III - Stage II + Lunotriquetral disruption
Stage IV - Stage III + Lunate dislocation +/- median nerve symptoms 25%-ish
Treatment of Acute Perilunate Dislocations
Emergent reduction & splinting
Open reduction, ligament repair with anchor sutures (+/- washing line technique), K-wire stabilisation +/- CTD
Outcomes:
Decreased risk of cartilage/nerve damage
Return to full function unlikely
Reduced grip strength and stiffness common
Treatment of Chronic Perilunate Dislocations
> 8/52 old - proximal row carpectomy
Chronic injuries with degenerative changes - total wrist arthrodesis
Transient ischaemia of lunate
12.5%
Benign/self-limiting
1-4 months post-lunate/perilunate dislocation
