Proximal interphalangeal dislocation (finger)

Background

Distal interphalangeal dislocation (DIP), proximal interphalangeal dislocation (PIP), and metacarpophalangeal dislocation (MCP) joints of the finger shown.

Volar/anterior finger anatomy.

Lateral finger anatomy.

• 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

Hand Anatomy

• Volar = anterior = dorsal
• Dorsal = posterior = palmar

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

• Distal finger
  • Finger amputation
  • Fingertip laceration
  • Nail avulsion
  • Nailbed laceration
  • Subungual hematoma
• Other finger/thumb
  • Boutonniere deformity
  • Mallet finger
    • Swan neck deformity
  • Jammed finger
  • Jersey finger
  • Trigger finger
  • Ring avulsion injury
  • De Quervain tenosynovitis
  • Infiltrative tenosynovitis
  • Metacarpophalangeal ulnar ligament rupture (Gamekeeper's thumb)
• Hand
  • Dupuytren contracture
• Wrist
  • Drummer's wrist
  • Ganglion cyst
  • Lunotriquetral ligament instability
  • Scaphoid fracture
  • Extensor digitorum tenosynovitis
  • Compressive neuropathy ("bracelet syndrome")
  • Intersection syndrome
  • Snapping Extensor Carpi Ulnaris
  • Vaughn Jackson syndrome
• General
  • Hand and finger dislocations
  • Hand and finger fractures
  • Hand and finger infections
  • Gout and pseudogout
  • Hand and finger tendon injuries
  • High-pressure injection injury
  • Osteoarthritis
  • Rheumatoid arthritis
  • Ring removal

Evaluation

PIP posterior 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

• 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

• Place Alumifoam splint on side of dislocation
  • 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
  • Splint should never extend onto the palm
• 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