Hand and finger dislocations

Types

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

MCP Joint

• Usually due to hyperextension forces that rupture volar plate causing dorsal dislocation
• Two types:
  • Simple: subluxation
    • Joint appears hyperextended to 60-90 deg
  • Complex: dislocation
    • MCP joint is in moderate hyperextension w/ 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

Reduction

• Do NOT hyperextend joint (may convert subluxation into complete dislocation)
• Flex the wrist to relax the flexor tendon
• Apply pressure over dorsum of proximal phalanx in distal and volar direction

Management

• Splint w/ MCP joint in flexion
• Refer to hand surgeon

CMC Joint

• Uncommon due to strong ligaments and insertions of wrist flexors/extensors
  • Cause is usually result of high-sped mechamisms
• Dislocates usually dorsally and associated w/ fracture(s)

Reduction

• Traction and flexion w/ simultaneous longitudinal pressure on metacarpal base

Management

• Refer to hand surgeon

Thumb

IP Joint

• Uncommon
• Dislocations often associated w/ open injuries

Reduction

• Median nerve block
• Reduce similar to IP joint of other digits

Management

• Immobilization in mild flexion for 3wk is usually all that is required

MCP Joint

• Like other MCP joint dislocations, may be simple or complex

Reduction

• Radial and median nerve blocks
• Pressure directed distally on base of prox phalanx w/ metacarpal flexed and abducted

Management

• Stable reduction: Immobilize in thumb spica w/ MCP joint in 20 deg flexion for 4wk
• Unstable reduction: ORIF

MCP Ulnar Ligament Rupture

• Also known as gamekeeper's thumb or skier's thumb
• Ulnar ligament ruptures at insertion into prox phalanx (due to radial deviation of MCP)
• X-ray (perform before joint stressing)
  • Bony avulsion from insertion of UCL into proximal phalanx
  • Associated condylar fracture
  • Proximal phalanx volar subluxation and radial deviation suggests complete UCL rupture
• Exam
  • Swelling and localized tenderness over ulnar border of joint
  • Weakness of pinch
  • Partial versus complete rupture
    • Valgus stress testing with joint in full extension and in 30 deg of flexion
      • >35 deg of joint laxity or 15 deg of laxity beyond that present in uninjured thumb is consistent w/ complete UCL rupture

Management

• Partial rupture
  • Immobilize in thumb spica for 4wk
• Full rupture
  • Referral within 1wk

Differential Diagnosis

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

See Also

• Hand and Finger Diagnoses (Main)