Proximal interphalangeal dislocation (finger)

Background

• Common; due to axial load and hyperextension
• Dorsal dislocation occurs when volar plate ruptures
• Lateral dislocations occur when one of collateral ligaments ruptures with at least partial avulsion of volar plate from middle phalanx

Differential Diagnosis

Hand and finger dislocations

• Finger dislocations
  • Distal interphalangeal dislocation (finger) (DIP)
  • Proximal interphalangeal dislocation (finger) (PIP)
  • Metacarpophalangeal dislocation (finger) (MCP)
• Thumb dislocations
  • Interphalangeal dislocation (thumb) (IP)
  • Metacarpophalangeal dislocation (thumb) (MCP)
• Hand dislocations
  • Carpometacarpal dislocation

Management

• Consider digital block for pain control

Dorsal/Posterior

• Flex wrist, then hyperextend the joint
• Apply longitudinal traction followed by dorsal pressure to phalanx base
• Irreducible dislocation likely due to entrapment of avulsion fracture, profundus tendor or volar plate
  • Without initial hyperextension, can be difficult to disengage from any trapped soft tissue
• Post reduction, look for central slip rupture, which may lead to Boutonniere deformity

Volar/Anterior

• Flex wrist then hyperflex the affected joint
• Apply gentle traction then extend the joint
• Often need open reduction due to volar plate entrapment

Splinting

• Stable Reduction: 3wk of immobilization in 20-30 deg of flexion
• Unstable reduction: Surgery
  • Displacement occurs during active range of motion
  • Displacement occurs during passive stressing of joint
  • >20 deg of deformity and instability with lateral testing

See Also

• Hand and finger dislocations