Metacarpophalangeal dislocation (finger)

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Background

  • Also known as the MCP joint
  • Usually forces that rupture volar plate cause dorsal dislocation

Clinical Features

  • Mechanism: hyperextension
  • Finger pain/deformity

Differential Diagnosis

Hand and finger dislocations

Hand and finger injuries

Evaluation

Types

  • Simple: subluxation
    • Joint appears hyperextended to 60-90 deg
  • Complex: dislocation
    • MCP joint is in moderate hyperextension with metacarpal head prominent in palm
    • Volar plate is interposed in MCP joint space
    • X-ray may show seasamoid within joint space (pathognomonic)
      • Closed reduction is not possible

Management

Reduction

  • Traction alone may convert simple MCP dislocation may convert it to a complex dislocation [1]
  • Dorsal dislocation
    • Flex the wrist to relax the flexor tendon
    • Hyperextend the joint
    • Apply pressure over dorsum of proximal phalanx in distal and volar direction
  • Volar dislocation
    • Rare, will likely need open reduction
    • If attempting closed reduction, push finger into the MCP joint and then hyperflex joint
    • After hyperflexing, pull traction and extend finger, using thumbs to guide proximal finger into place [2]

Splinting

  • Splint with MCP joint in flexion
  • Refer to hand surgeon within 2 weeks

Disposition

  • Outpatient management

See Also

External Links

References

  1. Horn A. Management of Common Dislocations. In: Roberts and Hedges' Clinical Procedures in Emergency Medicine. 6th ed. Philadelphia, PA: Elsevier; 2014.
  2. Davenport M. Procedures for orthopedic emergencies. In: Bond M, ed. Orthopedic Emergencies: Expert Management for the Emergency Physician. Cambridge: Cambridge University Press; October 31, 2013.