Lunotriquetral ligament instability

Background

• Ulnar equivalent of the scapholunate ligament injury
• May be confused with other causes of ulnar-sided wrist pain
• Results from FOOSH with impact on hypothenar eminence

Clinical Features

• Localized tenderness on ulnar aspect of wrist just distal to ulna

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

Evaluation

• X-ray (note: imaging is often normal with this injury)
  • PA - Widening of the triquetrolunate joint space
  • Lateral - volar intercalated segment instability is seen
    • Lunate tilts palmar producing zigzag pattern (opposite of scapholunate injury)

Management

• Ulnar gutter splint or short arm posterior mold
• Refer to orthopedic surgery

Disposition

• Discharge with ortho follow-up