Proximal interphalangeal dislocation (finger)

Background

• Most common finger dislocation
• Volar plate ruptures in both dorsal and volar PIP dislocations
• Lateral dislocations occur when one of collateral ligaments ruptures with at least partial avulsion of volar plate from middle phalanx

Clinical Features

Right fifth PIP phalanx dislocation

• Mechanism: Due to axial load and hyperextension
• Finger pain/deformity
• Evaluate for extension into joint as open dislocations are common

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

Hand and finger injuries

• Radiograph positive
  • Hand and finger fractures
  • Hand and finger dislocations
  • Triquetrolunate ligament instability
• Radiograph negative
  • Dupeytren contracture
  • Boutonniere deformity
  • Hand and finger tendon injuries
  • Ganglion cyst
  • De Quervain tenosynovitis
  • Intersection syndrome
  • Drummer's wrist
  • Extensor digitorum tenosynovitis
  • Vaughn Jackson syndrome
  • Snapping Extensor Carpi Ulnaris
  • Compressive neuropathy, "bracelet syndrome"
  • Scaphoid fracture
  • Osteoarthritis
  • Infiltrative tenosynovitis
  • Gout
  • Rheumatoid arthritis
  • Trigger finger
  • Mallet finger
    • Swan neck deformity
  • Jersey finger
  • Jammed finger
  • Subungual hematoma
  • Fingertip laceration
  • Metacarpophalangeal (MCP) ulnar ligament rupture (Gamekeeper's thumb)
  • Nail avulsion
  • High-pressure injection injury

Evaluation

PIP dislocation of right fifth phalanx

• X-ray finger (PA and lateral)
  • True lateral of only the finger instead of hand will help detect subtle avulsion fractures

Management

Reduction

Digital block

• Dorsal
  • Flex wrist
  • Hyperextend the joint
  • Apply longitudinal traction followed by dorsal pressure to phalanx base
  • Irreducible cases 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
  • Often need open reduction due to volar plate entrapment
  • Flex wrist then hyperflex the affected joint
  • Apply gentle traction then extend the joint

Splinting

• Stable dorsal reduction: 3wk of immobilization in 20-30 deg of flexion
  • If volar dislocation, may have injury to central slip of the extensor tendons, so must be splinted in full extension for 3 weeks to prevent Boutonniere deformity
• Unstable reduction: Surgery
  • Displacement occurs during active range of motion or passive stressing of joint
  • >20 deg of deformity and instability with lateral testing

Disposition

• Outpatient
  • If reduced, with follow up within two weeks with hand specialist

See Also

• Hand and finger dislocations

References

Authors

Ross Donaldson, Ted Fan, Daniel Ostermayer, Neil Young