Interphalangeal Joint Dislocation

Aetiology

  • Hyperextension injury; direct axial blow
  • Almost always dislocate posteriorly

Clinical presentation

  • Pain and deformity of the affected digit

Investigations

  • X-ray - AP and lateral

Management

  • PIP - closed reduction and buddy taping (or splinting)
  • DIP - closed reduction +/- splinting
  • Head of phalynx can button-hole through volar plate, causing volar plate entrapment which blocks reduction → open reduction required
  • If associated fracture renders the joint unstable, additional fixation/repair is required

Complications

  • Delayed presentation causes degeneration of the articular surface and profound stiffness of the finger
    • Impossible to reduce, may require fusion
  • Recurrent instability due to associated fracture