lunate and peri lunate dislocation

Question 1

mayfield classification

Answer 1

1. failure of scapholunate ligament
2. failure of lunocapitate dissociation
3. failure of LT ligament - perilunate
4. palmar dislocation of lunate at the radiocarpal joint

Question 2

management of lunate dislocations

Answer 2

closed reduction:
- traction and hyperextension
- thumb to reduce lunate
- hold lunate reduced - distract and flex wrist to reduce capitate onto lunate

open reduction:
1. extended carpal tunnel release - relieve pressure on median nerve and reduce lunate
2. dorsal approach - if volar unsuccessful - utility approach - 3rd compartment berger flap
Berger flap - ligament preserving - splits dorsal intercarpal and radiotriquetral in line with fibres

Definitive
- reduce carpus and K-wire transfixation
- repair scapholunate ligament - dorsal (most important)
- repair lunotriquetral and capsule rent volarly through carpal tunnel