Simple DIP Dislocations
Pure dislocations of the finger DIP or thumb IP joints are RARE – usually these are mallet fracture dislocations with volar subluxation of the distal phalanx (dorsal fracture dislocations are rare also).
When a pure dislocation occurs, it is usually dorsal, with an open wound.
– closed reduction and splinting, 3 weeks
– if open, irrigation and debridement, reduction, splint
Irreducible DIP Dislocations
Five distinct mechanisms:
1. pure dorsal dislocation with entrapped volar plate – probably most common
2. entrapped FDP
3. entrapped osteochondral fracture
4. buttonholing of the distal condyles of the middle phalanx through the FDP
5. chronic dislocation
– if truly irreducible, treat with open reduction, then a brief period of immobilization
– chronic dislocations (after 2-3 weeks) likely require open reduction, which can be done from the dorsal, volar, or midlateral sides.